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View Full Version : Suspension Bushings - Delrin, Rulon or Other



NickP
11-03-2016, 10:55 AM
On more than one occasion, discussions regarding what bushing material should be considered versus stock replacement rubber units have arisen here so I thought for the sake of keeping it real, maybe a solid conversation might be in order. For starters, I am nor have I ever been a scientist, chemist or engineer so I am unable to unequivocally delineate data with any sort of authority so I'll leave that effort to others. I can however thanks to the internet, google and other sources, search for answers and draw some conclusions based upon white papers and other available data. So, what I'd like to open the floor with is real life experiences and other known facts - No name calling or insinuations allowed - Just the facts - opinions are great, but we all know the rest of the saying.

Some reading of properties of plastics and their derivatives says there's a lot to choosing the right material. One material I found is Rulon. https://en.wikipedia.org/wiki/Rulon_(plastic). 142 seems to be a possibility. Others mixes are within the scope of the issue too. http://www.tstar.com/materials?__hstc=71297167.efffe9e1e7916a03bc080b40 399b4acd.1478125167868.1478125167868.1478146472767 .2&__hssc=71297167.1.1478195366583&__hsfp=3478827707&hsCtaTracking=37fdf901-4313-4d36-9c49-9ccbffa91c5c%7C8fd6b677-7356-4b0f-bea4-7ffe7c246a98#home/?__hstc=71297167.efffe9e1e7916a03bc080b40399b4acd. 1478125167868.1478125167868.1478146472767.2&__hssc=71297167.1.1478195366583&__hsfp=3478827707&hsCtaTracking=37fdf901-4313-4d36-9c49-9ccbffa91c5c%7C8fd6b677-7356-4b0f-bea4-7ffe7c246a98&view_32_search=rulon&view_32_page=1

For mass production, cost may outweigh the complete exercise due to Rulon's cost but for the occasional use it might be good.

JUMP IN!

chevynut
11-03-2016, 11:04 AM
http://www.boedeker.com/rulon_p.htm?utm_source=google&utm_medium=cpc&utm_campaign=Rulon&utm_content=rulon%20plastic&utm_term=rulon%20plastic&gclid=CjwKEAjwwOvABRC08aedoZ_lnTMSJACs_cbut3OlOsn-GNmVdDeFCANPNnJkPRhiKv5wFgsOYBYvjBoCjRLw_wcB

I personally think that stuff is way too hard to make a good bushing material that's somewhat compliant. It's 60-75 or so Shore D....


Durometers of various common materials
Material
Durometer
Scale


Bicycle gel seat
15–30
OO


Chewing gum (https://en.wikipedia.org/wiki/Chewing_gum)
20
OO


Sorbothane (https://en.wikipedia.org/wiki/Sorbothane)
30–70
OO


Rubber band (https://en.wikipedia.org/wiki/Rubber_band)
25
A


Door seal
55
A


Automotive tire tread (https://en.wikipedia.org/wiki/Tread)
70
A


Soft wheels of roller skates (https://en.wikipedia.org/wiki/Roller_skates) and skateboard (https://en.wikipedia.org/wiki/Skateboard)
78
A


Hydraulic O-ring (https://en.wikipedia.org/wiki/O-ring)
70–90
A


Hard wheels of roller skates and skateboard
98
A


Ebonite rubber (https://en.wikipedia.org/wiki/Ebonite)
100
A


Solid truck tires
50
D


Hard hat (https://en.wikipedia.org/wiki/Hard_hat) (typically HDPE (https://en.wikipedia.org/wiki/High-density_polyethylene))
75
D

chevynut
11-03-2016, 11:13 AM
I think the best bushing material has to be relatively firm, not soft like rubber or hard like Delrin, and must have good lubrication properties. Solid bushings (like hard plastic or aluminum) work okay where there's only rotation, but they transmit the most NVH and need to be lubricated. Rubber allows too much flexing and movement of suspension components, but it's good as far as not transmitting NVH. Rubber tears and binds because the inner and outer sleeves are bonded to it so it's always in shear, restricting motion. Polyurethane is the plastic of choice because it can be made in different hardnesses, the inner sleeve slides on the polyurethane giving better motion without binding, and it can be impregnated with graphite (Polygraphite) to improve lubricity. Cost doesn't seem to be an issue with Polyurethane as it is with Teflon. IMO Delrin is too hard for most applications, and Teflon is too soft and easily deformable. Heims give good articulation but are bad at transferring NVH. The industry has chosen polyurethane, and I think there are good reasons behind it.

Rick_L
11-05-2016, 09:54 AM
Seems to me that the automotive industry in general has chosen rubber not PU.

For performance applications, a harder rubber than OEM would be better, but pu is much easier to work with for short runs and does not require bonding, which often requires process tweeking.

Everything is a compromise, what part of your specs do you allow to be deleted or degraded first?

chevynut
11-18-2016, 08:15 AM
Copied from my chassis assembly thread:

Yesterday I decided to take a look at something I've long speculated about with regard to poly suspension bushings. RD has said that he doesn't like Poly bushings because they "bind" the suspension. Car Creations published a video showing how a rear C4 suspension supposedly "binds" and hangs up when poly bushings are used, limiting free suspension travel. I think that video was biased and assembled to help sell their products and not representative of a proper installation. Based on how the poly bushings are supposed to work, that "binding" shouldn't happen. The bushings should be pressed into the suspension part, and the steel sleeve in the center should be lubed and it should rotate within the bushing, and the bushing should not rotate within the suspension component. The diameter of the center sleeve is larger than the diameter of the hole, so there is preload on the bushing when installed.

I had previously assembled my C4 dogbones with new Polygraphite bushings from P-S-T. They rotated fairly easily, but not as easily as I thought they should especially after sitting a while. So I took them back off and did some measuring. It turns out that the width of the front bushings when installed in the dogbones was around .020" or more WIDER than the length of the inner steel sleeve in all 4 locations. The inboard washers actually made an imprint in the bushings. The result of this is that the bushings were "pinched" between the frame parts as the bolts were torqued down. This causes a lot of friction in the assembly, which restricts free movement. It also forces the grease out from the sides of the bushing and eventually causes them to squeak.

I pulled the bushings back out of the dogbones and faced them down on my lathe until the installed width was the same as the sleeve length. I didn't want any side to side movement so I tried not to make them too narrow. I found that 3 of the 4 rear dogbone bushings were the same width as the sleeve or slightly narrower, but one was significantly wider. So I faced that one down too, so now my bushings are "blueprinted" :razz:. I don't know why the manufacturers make them wider than they need to be, but it could be the tolerance in the width of the dogbones which isn't tightly controlled.

After re-lubing everything and torquing the front bolts, the dogbones operate quite a bit more freely than before. I plan to do this with the lower front a-arms as well, to make sure they rotate freely. I think this problem is why some people don't like poly bushings and probably why they squeak so bad in some applications. You MUST lubricate the sides of the bushings too because they turn with the suspension movement.

NickP
11-18-2016, 03:39 PM
NVH - I would assume, relative to our slice of heaven, that each individual has their own threshold of tolerance relative to this condition within his/her own car and in this case, a 50+ year old one at that. Isolating noise in this instance, i.e. a C4 suspended vehicle shouldn't be that difficult especially due to the rear IRS essentially floating with only very few components transmitting a sound. Batwing - two mounting points isolated by either rubber or poly. The nose of the third member assembly attached with a form of a ladder or other form of extension typically with a poly rod end. Now, enter the anti-sway bar - isolated by rubber or poly at two points along with the connectors being anything from a rod end or a simple bolt with poly or rubber locators. If a stock spring is utilized there is a pretty good sounding board there but again, it's an integral component isolated by the three previously mentioned locations. If coil over shocks are utilized and each of the mount points have spherical bearings I suspect it might transmit some undesirable noise. The use of poly here will address that though.

For the bulk of my past hotrods, I simply cranked up the stereo for the "street car" and for the most part the car had so many other detectable outpourings of noise and vibration I really never noticed them because I was having too much fun.

I'm looking at a Delran "Acetal AF blend, supplied as a 2:1 blend of Acetyl AF-100 and Acetal 150 resins" now to play with for some new dogbone and camber rods. Newman had a huge price attached to their product but I think I have a solution that can be very competitive.

It's fun to try if for no other reason than to stay out of the bars at night.

chevynut
11-18-2016, 04:48 PM
If coil over shocks are utilized and each of the mount points have spherical bearings I suspect it might transmit some undesirable noise. The use of poly here will address that though.

I just bought some spherical bearings from Aldan and noticed they have a steel bearing with a poly race. That was a little surprising. In front I'll be using bushings with the t-bar on bottom and probably the spherical bearings on top, although the poly bushings don't need to deflect much there. In the rear there's more movement so I may use the spherical bearings top and bottom.


Newman had a huge price attached to their product but I think I have a solution that can be very competitive.

You have no competition from Newman. He must have sold out all of his remaining parts because his site is totally shut down now.

NickP
11-18-2016, 07:43 PM
I just bought some spherical bearings from Aldan and noticed they have a steel bearing with a poly race. That was a little surprising. In front I'll be using bushings with the t-bar on bottom and probably the spherical bearings on top, although the poly bushings don't need to deflect much there. In the rear there's more movement so I may use the spherical bearings top and bottom.



I think that's just a PTFE liner

chevynut
11-19-2016, 07:20 AM
I think that's just a PTFE liner

Here's what the Aldan website shows for the bearings I ordered from Summit, using the Aldan part number.



https://aldanamerican.com/wp-content/uploads/2014/09/ALD-9-300x300.jpg
However, on the ones I got the whole race is black. I found this pic on the QA-1 website and it looks like what I got...nylon/PTFE race. I wonder if this is strong enough for the coilovers.



https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcSqLuLyYzxiJHYhnpAWcbYF1SnDaGll1 oSQSWzg2jgV65Xhj7ofOQ
"QA1’s EMB Nylon Race Series spherical bearings feature an injection molded race for superior ball to race conformity. This race results in the bearing being completely self-sealing and self-lubricating, keeping dirt and debris out. EMB Series spherical bearings are ideal for low load, low oscillation applications."

NickP
11-19-2016, 07:48 AM
Here's what the Aldan website shows for the bearings I ordered from Summit, using the Aldan part number.



https://aldanamerican.com/wp-content/uploads/2014/09/ALD-9-300x300.jpg
However, on the ones I got the whole race is black. I found this pic on the QA-1 website and it looks like what I got...nylon/PTFE race. I wonder if this is strong enough for the coilovers.



https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcSqLuLyYzxiJHYhnpAWcbYF1SnDaGll1 oSQSWzg2jgV65Xhj7ofOQ
"QA1’s EMB Nylon Race Series spherical bearings feature an injection molded race for superior ball to race conformity. This race results in the bearing being completely self-sealing and self-lubricating, keeping dirt and debris out. EMB Series spherical bearings are ideal for low load, low oscillation applications."

Interesting; oddly enough, I was reviewing them last night also. Then, I too wondered about the "low load" and became submerged in trying to understand the imposed loads to them and that drifted to all joints within the suspension system, be it stock or poly etc. Once there, my confusion grew so I went to bed and didn't sleep due to calculating all night. I'm exhausted this morning. I still have no clue as to what kind, static or dynamic, loads the various points see and the selection of spherical bearings is way wide to add to my state of distress.

chevynut
11-19-2016, 08:03 AM
LOL! Hope you're better this morning after a cup of coffee. :D

The best way to think about coilover shock loads, imo, is to simply multiply the total spring compression at rest by the spring rate. If I have a shock with a 4" stroke and it runs 2" compressed with a spring preload of 1" that's 3" of total compression and the static axial load with a 400 lb/in spring would be 1200 pounds. If the shock bottoms out the total compression is 5" and there would be a 2000 pound axial load. QA-1 says the maximum axial load on these nylon race bearings is 2000 pounds. Summit's specs say 5000 pounds for the same part.

55 Rescue Dog
11-19-2016, 02:51 PM
All friction aside, I think if you take a good look at the Banski trailing arms, or something similar, it is the way to go for the C4 IRS. I have no problem with poly bushings anywhere in the suspension, except the trailing arms.
https://www.banskimotorsports.com/c4-trailing-arms.html
They use Aurora rod ends rated at 8200lbs static load each.
https://www.banskimotorsports.com/key-components--rod-ends.html

chevynut
11-20-2016, 07:56 AM
I have no problem with poly bushings anywhere in the suspension, except the trailing arms.

Here we go again ....clearly your "problem" is that you don't understand what's really going on in a C4 IRS or you wouldn't make comments like that and buy those harsh riding, wear-prone, over-priced non-GM trailing arms meant for racing, not street use. And what's the need for those expensive custom-machined cones that are made for high offset angles? You don't need them and will never see anywhere near 22 degrees of offset in a C4 IRS application. You could have bought 4 swaged aluminum rods and 8 of those cheap Aurora low carbon heims and made them yourself for less than half their price if that's what you wanted. And you wouldn't have "panicked" either. http://www.trifivechevys.com/images/smilies/biggrin-new.png

I already showed that poly bushings are not an issue for use in a stock C4 dogbone. The deflection angles are small and poly is not rigid material. If you have data (numbers) proving differently, then post them.

55 Rescue Dog
11-20-2016, 08:48 AM
Of course poly dog bones probably feel nice, and free hanging off the ground in the shop, but under heavy acceleration/braking/cornering loads, it's just not convincing at all.

NickP
11-20-2016, 01:51 PM
Of course poly dog bones probably feel nice, and free hanging off the ground in the shop, but under heavy acceleration/braking/cornering loads, it's just not convincing at all.

RD, if you're going to make a statement then please provide data, numbers, a white paper or something, be it yours or from some qualified source that validates your hypothesis. Shit man, anyone can drop a turd but until you compare them for texture, color, smell and resident chemicals, it's still just a turd.

55 Rescue Dog
11-20-2016, 04:21 PM
Dammit, I'm sorry I keep forgetting this is the CN NP engineering forum where everything is proven on paper without ever driving a car from their R&D department. Me neither, but it is only simply a discussion until someone actually drives their car to show what works, and what doesn't. I have plenty of white papers that I wipe with, and a good vent fan too.

oceangoer
11-20-2016, 07:25 PM
I have decided to utilize spherical rod ends for my control arms.. Lowest friction and many other issues.

I've used them in the lower caster struts for many years with great results.

Has anyone used poly-graphite front control arm bushings ??

http://p-s-t.com/series-220203-polygraphite-front-end-control-arm-bushing-set.html#!model%3DCORVETTE%7C%7Cyear%3D1994%7C%7Cm ake%3DCHEVROLET


6571

55 Rescue Dog
11-21-2016, 05:56 AM
According to this article, rubber bushings have no friction in rotation, but poly bushings do have friction that can change under load, and miles.

http://www.elephantracing.com/techtopic/polyurethanefriction.htm

BamaNomad
11-21-2016, 06:22 AM
That's a pretty good article with some good information, although the bottom line suggestions seem to apply only to Porsches.. :)

A point was made that there was no 'friction' in rubber bushings which is true up until the rubber 'separates'... :) While there is no friction in a good rubber bushing, there is something else that we would prefer not to be there ... 'a spring constant'. Ideally, in a suspension system there would be no friction, no stiction, no spring constant, and no translation of the rotating axis, but of course we do not live in a perfect world, and there's no perfect solution to this problem... thus we have several options available depending on where we place the primary emphasis.

chevynut
11-21-2016, 08:51 AM
A point was made that there was no 'friction' in rubber bushings which is true up until the rubber 'separates'... :-) While there is no friction in a good rubber bushing, there is something else that we would prefer not to be there ... 'a spring constant'.

A rubber bushing is bonded to the sleeve and the shell, so by it's design it acts as a spring as you said. Add up all the little springs in each bushing and you get a lot of "binding" in the suspension which inhibits articulation. It's very hard to move a stock C4 rear suspension, or even a front C4 suspension. I have to loosen the nuts on the upper a-arm shafts to get them to move in my jig. They're always under shear loading, so they eventually fail by tearing.

A poly or other polymeric bushing slides on the sleeve so there is no such "springiness" when designed and installed correctly. I found that mine worked a lot more smoothly when the bushings were the same width as the sleeve length. I think that's how they're supposed to be designed, but the manufacturers can't anticipate the tolerances in the suspension parts so they seem to cut them to the large side which causes friction on the sides of the bushings. In any case, you should lube the sides too when assembling the suspension.

The spherical bearings probably provide the best articulation but the tradeoff is NVH and wear. I think the poly bushings are better for a street-driven car. Even a solid axle with a 4-link has some angular displacement as the car rolls. But poly bushings work well there too.

55 Rescue Dog
11-21-2016, 03:50 PM
A rubber bushing is bonded to the sleeve and the shell, so by it's design it acts as a spring as you said. Add up all the little springs in each bushing and you get a lot of "binding" in the suspension which inhibits articulation. It's very hard to move a stock C4 rear suspension, or even a front C4 suspension. I have to loosen the nuts on the upper a-arm shafts to get them to move in my jig. They're always under shear loading, so they eventually fail by tearing.

A poly or other polymeric bushing slides on the sleeve so there is no such "springiness" when designed and installed correctly. I found that mine worked a lot more smoothly when the bushings were the same width as the sleeve length. I think that's how they're supposed to be designed, but the manufacturers can't anticipate the tolerances in the suspension parts so they seem to cut them to the large side which causes friction on the sides of the bushings. In any case, you should lube the sides too when assembling the suspension.

The spherical bearings probably provide the best articulation but the tradeoff is NVH and wear. I think the poly bushings are better for a street-driven car. Even a solid axle with a 4-link has some angular displacement as the car rolls. But poly bushings work well there too.
BS! All 4 link trailing arms need to move in 3 different arcs, whether IRS or solid axel. Up/down, twist, and side to side.
And if you really think about it, rubber bushings are actually less restrictive than even heim joints loaded. No friction, just a little progressive twisting of the rubber. If the bushings can't twist, then the trailing arm will try to, which is where the binding comes into play.

NickP
11-21-2016, 05:36 PM
BS! All 4 link trailing arms need to move in 3 different arcs, whether IRS or solid axel. Up/down, twist, and side to side.
And if you really think about it, rubber bushings are actually less restrictive than even heim joints loaded. No friction, just a little progressive twisting of the rubber. If the bushings can't twist, then the trailing arm will try to, which is where the binding comes into play.

How about this guys. I'll start another post about Rubber VS Poly and you that want to argue, go there.

chevynut
11-21-2016, 07:02 PM
I'm done arguing with RD because he has no clue about what's going on in these suspensions. The angular displacements are so small that it doesn't matter except in RD's imagination. Poly does allow some tiny amounts of twisting, as does rubber. He's totally full of shit and should just stick with his tire changing an cutting away offending sheetmetal to make tires fit. :D

oceangoer
11-25-2016, 03:29 PM
Chevynut,,, I get that.

BTW all, lots of nice input. I do enjoy learning and often re-learning... with few exceptions.

IMHO... We all should understand what we're about to modify prior to,, esp suspension and steering. IMHO that includes toe in, toe out, IC, Camber, caster, bump steer, jacking, Scrub, under steer, over steer and Roll Center as a minimum. And at the very least what happens when one lowers his car or changes the wheel offsets, esp reversed wheels. Well heck, that's just me, picky picky Engineer getting fussy....

In one installs that incorrect or inferior fuel pump etc, your in for a Tow,, maybe. Screw up the suspension, now your into serious issues.

MY Dad always told me that your Brakes, steering, and related suspension components are most important when one is in a Panic situation, like a panic stop, or in a corner in heavy rain, can't see well - is no time to wonder if your brakes are up to Par or if your car is going to over-steer in this slippery corner or what else...

But in my new Build, I'm sticking with spherical rod ends on my C4 rear control arms, Toe, and lower camber bars. I've had years of reliable driving wit these in the rear of my C4 Convert. Last thing I want is any side to side movement in my control arms or Camber rods. No idea yet to what I'll be using for the front control arms, poly-graphite or perhaps Del-a-Lums, photo below.

I'll not be ever installing rubber control arm bushings again ever. The front control arms in my C4 have 8K miles on genuine GM rubber control arm bushings that I installed in 2000 which was a complete sus rebuild. The rubber bushings are so hard now that when I changed the wheels and tires a few months ago, the front will still not settle. I don't need another project, but I'll be replacing the bushing in the front once again. Is there not a perfect control arm bushing ?

I don't mind fitting front C.A. bushings one by one as I have read that Chevynut successfully completed. I just really do despise doing anything twice, once is enough.

Thanks Guys, much appreciated...

Michael.. OH ya, did I read , more photos Well my old '56 has an old paint job, a 10 footer. But she's a sweetheart. The Body is Original,. not much else..

markm
11-25-2016, 03:43 PM
I'm done arguing with RD because he has no clue about what's going on in these suspensions. The angular displacements are so small that it doesn't matter except in RD's imagination. Poly does allow some tiny amounts of twisting, as does rubber. He's totally full of shit and should just stick with his tire changing an cutting away offending sheetmetal to make tires fit. :D

That good because your ruining this site.

NickP
12-01-2016, 02:17 PM
Experimental - 001

http://pic20.picturetrail.com/VOL1600/2283636/23877721/412986365.jpg

chevynut
12-01-2016, 02:27 PM
That good because your ruining this site.

I provide more technical input and project updates on this site than you even dream about. It's idiots like some of you who have nothing useful to add and just badmouth everyone else's projects that are ruining the site.

chevynut
12-01-2016, 02:29 PM
Experimental - 001

Nick, what holds those outer races in? Are you going to cut a snap-ring groove? Looks pretty cool. ;)

NickP
12-01-2016, 02:32 PM
AA spacer (AKA washer) and snap ring or maybe a Spiro Lock ring - the other side will have an adjuster/tensioner (threaded) that locks into position. Also a grease zerk.

oceangoer
12-01-2016, 02:51 PM
Nice job Nick, I like !!

Anxiously waiting your conclusion.

Grease Jerk, yes please.

Flat washers with spring washers ??

Michael....

NickP
12-01-2016, 03:05 PM
Nice job Nick, I like !!

Anxiously waiting your conclusion.

Grease Jerk, yes please.

Flat washers with spring washers ??

Michael....

I have some studying to do first but the tapered snap rings seem to have issues in other similar installs.


https://www.rotorclip.com/images/wysiwyg_images/new_images/multi_spiral.gif
https://www.rotorclip.com/spiral_ring_overview.php

Grease Zerk type: http://cdn6.bigcommerce.com/s-2znwcfi75a/products/280/images/581/140__37435.1460317216.1280.1280.jpg?c=2

55 Rescue Dog
12-01-2016, 03:17 PM
I provide more technical input and project updates on this site than you even dream about. It's idiots like some of you who have nothing useful to add and just badmouth everyone else's projects that are ruining the site.
Well your almost half right anyway. You set the example.

NickP
12-01-2016, 05:14 PM
55 RD, is it your intent to mess with every single post on this site? If your intent is to destroy it, then my suggestion to the owner is to do away with either the site, you or me so I don't have to witness the demise of it.

oceangoer
12-01-2016, 06:04 PM
Rick,

I was thinking more like a single layer spring washer on at least one side and Delrin Washers on both sides to locate the control arm(s) centers.
But, even this will prob need a S/S or hardened flat washer on each side placed between Delrin washers and the mounting bracket to prevent Galling.

Sure seems like a reasonable idea.
...

No doubt less costly than a set of rods ends and new threaded tubular Camber Arms.

Michael...

chevynut
12-01-2016, 07:19 PM
You set the example.

You're the one with your head tucked tightly up your ass and who can't understand simple engineering. You have dozens of posts questioning everything I've done on my frame, how bad the C4 suspension is, and no matter how many times it's explained to you, you just don't get it. You do your shit your own way and I'll do it mine so STFU about what I choose to do.

chevynut
12-01-2016, 07:25 PM
I have some studying to do first but the tapered snap rings seem to have issues in other similar installs.

What kind of issues? I would think a snap ring would work well if designed to take the side loads. I like your choice of grease zerks because they don't stick out like the regular ones. Do you have to machine the struts for the races, or did you make the races to fit? The early C4 struts would take two of the smaller ones.

NickP
12-01-2016, 08:47 PM
On several Johnny Joints I have here, the assembly width was pretty snug and is forcing the tapered end to roll up. I don't think it will be an issue in what I'm trying but I'd rather take a hard look at it. Also, the Johnny Joint's race is a one piece poly piece. The races I have are a PTFE mix. And yes, the race is cut to fit rather than removing material and reducing the section thickness. I'm waiting on the tap and the grooving tool/inserts now.

On the early C4 Camber Strut are both ends the same size on the outside of the forging end for end?

While we're on the rear suspension, where is the OAW wheel flange to wheel flange difference?

chevynut
12-01-2016, 08:59 PM
On the early C4 Camber Strut are both ends the same size on the outside of the forging end for end?

Not sure if this is what you're asking, but both bores are the same. I don't know why you'd be concerned about the outside but as far as I can tell you can put them in either way, meaning there isn't an inboard and outboard end like with the late ones. Here's an early one:

http://cdn6.bigcommerce.com/s-khgr7sy/products/906/images/2024/a207918149cf00fd506cf9_l__91371.1421110488.600.325 .jpg?c=2


While we're on the rear suspension, where is the OAW wheel flange to wheel flange difference?

It's in the knuckle. You know how the late knuckle is built and that the thick caliper bracket is separate on them. Here's a good comparison pic. Not sure where they got the "88.5" from.

http://www.hotrodjim.com/immages/trifive/C4/installtion_help/rear_knuckle_01.jpg

NickP
12-02-2016, 11:46 AM
http://pic20.picturetrail.com/VOL1600/2283636/23877721/412988762.jpg

55 Rescue Dog
12-02-2016, 02:50 PM
Looks good Nick, but some way other than snap rings to retain the bearings would be great. Either press fit, or something to clamp the bearing races.

chevynut
12-02-2016, 03:11 PM
Nick, since you'll have to do some machining anyhow for snap ring(s) why not open up the bore but leave a step on one side so you can use only one snap ring to hold it all together. No way would I trust a press-fit, especially a PTFE/plastic race into aluminum, and I think it would easily squeeze out without a positive retainer of some sort. The split race is going to make keeping it together challenging, imo. I think the Spiro-loks are made for lower side loads than the tapered snap rings.

55 Rescue Dog
12-02-2016, 03:27 PM
Putting a hardened steel snap ring in an soft aluminum groove snugly, that is going to narrow the assembly a lot, doesn't seem like a great idea though. Johnny joints are great, but they are much bigger than any other bushing for some reason. If someone modified and put together the right combinations of Johnny joints and links, I would have bought, or buy those. Dog bones with just RH threads is all that is need for those links, but not the camber links of course.

NickP
12-02-2016, 08:14 PM
Putting a hardened steel snap ring in an soft aluminum groove snugly, that is going to narrow the assembly a lot, doesn't seem like a great idea though. Johnny joints are great, but they are much bigger than any other bushing for some reason. If someone modified and put together the right combinations of Johnny joints and links, I would have bought, or buy those. Dog bones with just RH threads is all that is need for those links, but not the camber links of course.

You do realize that a Johnny Joint has a "Poly" race, right? Regardless of that, There are Johnny Joints that can be used with either Aluminum or Steel tubes and will fit within the confines of the two spaces where the current camber bar resides. It's a matter of a sleeve to reduce a 5/8" bore in the joint down to the hole size at the adjuster and the other end (knuckle) two thin washer shims with a 5/8" hole. That same JJ comes in left and right hand thread.

You mention purchasing them and talk with regards to the DogBones which I thought you already have. Not certain what you have going on there.

NickP
12-02-2016, 08:20 PM
Nick, since you'll have to do some machining anyhow for snap ring(s) why not open up the bore but leave a step on one side so you can use only one snap ring to hold it all together. No way would I trust a press-fit, especially a PTFE/plastic race into aluminum, and I think it would easily squeeze out without a positive retainer of some sort. The split race is going to make keeping it together challenging, imo. I think the Spiro-loks are made for lower side loads than the tapered snap rings.

I haven't studied the Spiro-Loks much yet. I'm confused about "positive retainer". Doesn't a piston pin in some applications use a form of spiro-lok?

chevynut
12-02-2016, 08:33 PM
I'm confused about "positive retainer". Doesn't a piston pin in some applications use a form of spiro-lok?

Yeah but a piston pin doesn't have a lot of side load, if any, so I spiro-loc works fine there. These strut rod bearings have some side loads although I don't think they're very high. To me the load will come from within, as the spherical bearing pushes on the races and tries to separate them. Seems to me the best choice would be the tapered snap ring and washer for that application.

NickP
12-02-2016, 08:50 PM
Still studying but there are several versions of them from a light duty to extra heavy duty. Regardless, retention of the bearing halves is not just the retainer ring but as you mentioned, the washer also. Still a lot to learn but nothing ventured nothing gained.

rockytopper R.I.P 5-13-2017
12-03-2016, 04:32 PM
NVH - I would assume, relative to our slice of heaven, that each individual has their own threshold of tolerance relative to this condition within his/her own car and in this case, a 50+ year old one at that. Isolating noise in this instance, i.e. a C4 suspended vehicle shouldn't be that difficult especially due to the rear IRS essentially floating with only very few components transmitting a sound. Batwing - two mounting points isolated by either rubber or poly. The nose of the third member assembly attached with a form of a ladder or other form of extension typically with a poly rod end. Now, enter the anti-sway bar - isolated by rubber or poly at two points along with the connectors being anything from a rod end or a simple bolt with poly or rubber locators. If a stock spring is utilized there is a pretty good sounding board there but again, it's an integral component isolated by the three previously mentioned locations. If coil over shocks are utilized and each of the mount points have spherical bearings I suspect it might transmit some undesirable noise. The use of poly here will address that though.

For the bulk of my past hotrods, I simply cranked up the stereo for the "street car" and for the most part the car had so many other detectable outpourings of noise and vibration I really never noticed them because I was having too much fun.

I'm looking at a Delran "Acetal AF blend, supplied as a 2:1 blend of Acetyl AF-100 and Acetal 150 resins" now to play with for some new dogbone and camber rods. Newman had a huge price attached to their product but I think I have a solution that can be very competitive.

It's fun to try if for no other reason than to stay out of the bars at night.


Nick I tend to agree with your second paragraph lol. Still doing that on my current one. I went from rubber to delrin in front arms. The ls1 dropped the rpm by 1000 over stock which reduced the most NVH lol. If you miss it just pull it in drive it feels just like 1965 again lol. Crazy thing is with total new suspension on all 4 the car still has a spot from 70-75 that has the most V just like when it was bone stock.

NickP
12-09-2016, 07:51 AM
Well, after reading specs etc. I have settled in on N5000 series Waldes Truarc snap rings for retention of parts.

chevynut
12-09-2016, 09:07 AM
Are you planning to sell new dogbones and strut rods, or just modify stock ones, or both? Any idea on cost yet?

NickP
12-09-2016, 12:13 PM
Are you planning to sell new dogbones and strut rods, or just modify stock ones, or both? Any idea on cost yet?

I do have the CNC program done for new but material isn't cheap and I don't know whether or not it would be cost effective.

Rick_L
02-06-2017, 05:53 PM
Just finished an environmental test on the polyurethane bushings on my Hellwig sway bar.

I went to move my rolling chassis and found that they had all disintegrated - just sitting there in the shop.

I think I'll get some rubber ones.

rockytopper R.I.P 5-13-2017
02-06-2017, 06:15 PM
What was the shelf life on your car just curious realizing you don't know when they were built. The hellwig purchased for my car appear to be rubber not poly but I could be wrong just FYI.

chevynut
02-06-2017, 09:46 PM
My Nomad had brand new rubber bushings that I installed in the a-arms and they were all cracked and nasty looking when I pulled the chassis out from under it. They never saw sunlight and were indoors all the time but looked like crap. My Polygraphite bushings have to be over a decade old now and still look like new. I have a bunch of extra left-over poly bushings I bought cheap on eBay a long time ago too, no telling how old they are but they look new too. My old rubber body mounts were new when I installed them and they were trashed (smashed, cracked, deformed) when I took them out. After sitting for several years with the body on, my poly body mounts still look new. I'll stick with polyurethane for now. I think it holds up to the elements better than rubber based on my experience.

NickP
02-07-2017, 10:23 AM
What was the shelf life on your car just curious realizing you don't know when they were built. The hellwig purchased for my car appear to be rubber not poly but I could be wrong just FYI.

To your point, if there is in fact a "Shelf Life" attributed to these products, has anyone seen it? I can't say that I ever have. To parallel the experience, recently I was going to utilize some old bushings that came with some RideTech shock units (very old - ten years) and discovered the very same phenomenon - powdered and crumbling. Have things changed that much with these poly compounds? Should those with older bushed cars be concerned?

Rick_L
02-07-2017, 10:36 AM
I don't think anything has changed. I had a Stanley dead blow hammer come apart the same way a few years ago. It just started crumbling. I've also had shoes with urethane soles do the same thing.

What I don't know is what compounds and chemistry are typically used in automotive bushings or how many variations there might be - or how to quickly tell what you have. What I do know is that I worked in an industry that uses a lot of urethane materials to make products water resistant and tough. Generally the most durable stuff was molded or extruded polyether based polyurethanes. Polyester based polyurethanes are slowly attacked over time by moisture. There are also 2 part compounds which run from junk to excellent, but they are also susceptible to mixing errors and moisture in the catalyst.

So there are a lot of choices and a lot of ways to go wrong.

rockytopper R.I.P 5-13-2017
02-07-2017, 10:57 AM
I restored my cutlass in 2010 with all new door and window seals that were suppose to be soft seal products purchased from OPGI. The door seals have held up but the vent seals are junk. They crumpled and turned to powder in less than 3 months after I installed them. I think company's are just selling us junk these days. I would be far better off if I had left the 45 year old seals in the car.

markm
02-07-2017, 11:12 AM
My $45 Snap-On test light with the coiled rubber lead went to hell in 5 years sitting in my tool box.

chevynut
02-07-2017, 12:25 PM
To parallel the experience, recently I was going to utilize some old bushings that came with some RideTech shock units (very old - ten years) and discovered the very same phenomenon - powdered and crumbling.

That's just bizarre, IMO. I've never seen anything like that with poly bushings.

hutchenc
02-19-2017, 04:40 PM
Was talking to my pop about polyurethane crumbling/deforming. He does machine work with delrin frequently (white, black, and the brown stuff, called AF...has teflon in it), but no poly (can't really machine polyurethane). Poly will change shape over time...it's soft enough that constant pressure on it will deform it. In suspension, especially where things are rotating, it'll ovalize over time..hard to say how long. As far as bushings coming apart...he's wondering if it's because of chemical reactions with grease. I know plenty of folks like it and have had good luck with it, but I don't trust it. .I'm sticking with delrin on everything except my sway bar bushings and body mounts.

oceangoer
02-19-2017, 05:02 PM
Poly Bushings,

Sure seems very strange to me that Poly suspension bushings failed. I've had them in my '56 for 10 years with no issues, not ever those pesky Squeaks. Not the first Car that I've used them on. Question is, with so many Junk parts on the market, are all the makers actually using the material components that they claim ?? Prob Not.

As far a Creep in Delrin, that's news to me in this application. Nylon of course does.

BTW, I installed new OEM rubber bushings in my C4 Convert in 2000 during the resto. Only 8000 miles heated garage are their hard and when I changed the wheels and tires the last Fall, this Car did Not settle back to ride height. Time to change...

In the build that I've just started with C4 suspension, the Front control arms will utilize Del-a-Lums, everything else are spherical rod ends. No more rubber bushing for me....

Question, whats the best means to remove these old hard rubber bushings ??

Rick_L
02-19-2017, 05:44 PM
I know from my industrial experience that it's easy to screw up most any plastic part. Especially 2 part urethanes, and any molded rubber. One of the keys to molding or extruding plastic is to dry it according to the manufacturers specs. A really dumb error in manufacturing will show up when you make the part - it turns out like crap, easy to see it's unacceptable. More subtle errors yield parts that look OK but are weak or have a short service life. Process control is even more difficult on rubber than plastic.

Then there is choosing the wrong material for the application. Remember this carefully - there are hundreds of polyurethane compounds that could be used for bushings. Dozens for acetal (Delrin) or nylon. Likewise for rubber. Some manufacturers substitute cheaper materials, duh.

Just because GM used one material and it worked great doesn't mean the aftermarket duplicates it correctly. And just because some supplier like Energy Suspension uses one material successfully doesn't mean every competitor can, or that Energy Suspension (or anyone else) does it right every day. Sometimes you are at the mercy of your material supplier's quality also. There are just lots of ways to go wrong.

hutchenc
02-19-2017, 08:15 PM
Question, whats the best means to remove these old hard rubber bushings ??

I put the GW del-a-lums in my front C4 control arms this past Fall. Not too difficult, just time-consuming. I drilled out the rubber bushings with a 3/16" bit (maybe it was 1/8") and used a sharp exacto knife to cut the shoulders off as well...once you drill a bunch of holes in them, they come out fairly easily.

chevynut
02-20-2017, 08:09 AM
As far a Creep in Delrin, that's news to me in this application. Nylon of course does.

Never heard of cold flow in Delrin or Nylon. I know PTFE(Teflon) does cold flow. "Nylons have good resistance to creep and cold flow compared with many less rigid thermoplastics. " Most rigid plastics have good cold flow resistance. I've never heard of any problems with cold flow in polyurethane except possibly under extreme long-term high-load conditions or high temperatures. Where does that exist in a suspension? Also, with pressed in sleeves and side containment it has nowhere to go.


Advantages of Polyurethane When Compared to Conventional Materials

...vs. Rubber
...vs. Metal
...vs. Plastic





High abrasion resistance
High cut & tear resistance
Superior load bearing
Thick section molding
Colorability
Oil resistance
Ozone resistance
Radiation resistance
Broader hardness range
Castable nature
Low pressure tooling




Lightweight
Noise reduction
Abrasion resistance
Less expensive fabrication
Corrosion resistance
Resilience
Impact resistance
Flexibility
Easily moldable
Non-conductive
Non-sparking




High impact resistance
Elastic memory
Abrasion resistance
Noise reduction
Variable coefficient of friction
Resilience
Thick section molding
Lower cost tooling
Low temperature resistance
Cold flow resistance
Radiation resistance





http://www.precisionurethane.com/urethane-advantage.html


BTW, I installed new OEM rubber bushings in my C4 Convert in 2000 during the resto.

It was my understanding that neither GM nor any aftermarket suppliers ever offered C4 suspension bushing replacements. They only offered replacement control arms and other suspension parts with rubber bushings. At least that's what the Corvette guys have said.


In the build that I've just started with C4 suspension, the Front control arms will utilize Del-a-Lums, everything else are spherical rod ends. No more rubber bushing for me....

The downside to DelAlum and spherical rod ends is NVH. It will increase. IMO polyurethane is a very good material choice considering the tradeoffs and it has proven to last a long time in these suspension applications. Despite all the "theoretical" complaints about them, there are millions of cars out there using them successfully. As I found out on my Nomad chassis, one of the main reasons they squeak and restrict articulation is when the poly bushing is too wide for the application and is compressed too tightly.

chevynut
02-20-2017, 08:12 AM
(can't really machine polyurethane).

I didn't have too much trouble machining my lower a-arm and dogbone bushings to the proper width to reduce friction, but it certainly doesn't machine like metal. I noticed some bushings are harder than others too.

Rick_L
02-20-2017, 10:08 AM
Polyurethane in the hardness typically seen in automotive bushings is too soft to machine well. I have had some success at machining pu compounds that are glass filled, but those are probably too hard for bushings. Solved a problem with a molded o-ring groove in pu that had molding flash in the groove - machining provided a more accurate groove with no flash - but it cost more too.

hutchenc
02-20-2017, 11:21 PM
I didn't have too much trouble machining my lower a-arm and dogbone bushings to the proper width to reduce friction, but it certainly doesn't machine like metal. I noticed some bushings are harder than others too.

I should have clarified that...my dad does a lot of precision machining. It's not easy to get poly within precise specs on small parts like it is with Delrin and certainly metal. Like Rick said...it's just too soft most of time. On applications like this (automotive), tolerances are much higher. My dad does a lot of stuff for the aviation industry. Short story...he was all worried about the precise size of that small shaft he machined for my steering column...he machined the ends to an .005 tolerance. Just how he is. I'm sure when we started hitting it with the grinding wheel because it was a hair too big he cringed! Haha!

At the end of the day, I just don't trust poly. My dad put some poly bushings in his '67 Corvette and they're garbage, squeak like no tomorrow. Since my brother never drives that car and it's been sitting in his garage for 2+ years (he owns it now), I think I'll end up inheriting it (which I'm fine with btw!) and will have to replace all those bushings. I honestly don't know what company made them. I had poly bushings in my rear leafs as well...I had to turn them down to get them fit the upper shackles quite a bit. Really pissed me off...why can't they make round bushings that fit? Will be running Delrin AF with sleeves soon. I suppose some companies make a good poly product, but there's a lot of junk on the market too and unfortunately it's hard to know which ones to trust.

I'll have poly sway bar bushings...on my second set now since I used the wrong brackets ;)

NickP
03-25-2017, 02:23 PM
An update, not complete yet. A couple more features to figure out.

http://pic20.picturetrail.com/VOL1600/2283636/23877721/413241484.jpg

NickP
03-25-2017, 05:57 PM
Added Snap Ring Grooves and center channel to reduce weight.

7028

NickP
02-21-2018, 09:37 PM
Still working through these dogbones in my spare time. I have renewed interest due mostly in part to access to a new HASS Machining Center and a willing owner that needs to put it to work.

I've settled in on PTFE lined spherical bearings rather than attempting to use the material and build them. Too many little parts to make. I did however thanks to some recent work with some off-road vehicles discover an "Anti-Wobble" addition to keep the dogbones in place so to speak. I had watched the old Newman YouTube video many times and noticed a rotation along the axis length of the dogbones and became a bit concerned with it marring the outer ends at the bearing area or wearing it out. It should work well for this application. Does well in rock crawlers, trophy trucks and Baha units.

55 Tony
02-22-2018, 05:03 AM
Hmm, just two days ago I was out for a little drive and heard my front end squeaking. Wondering if I can get a grease needle in there? Most of the front end was done so long ago that I forget what I used, and some of it I know is PU.

Oh, I didn't realize how old this thread was.

NickP
02-22-2018, 08:57 AM
Hmm, just two days ago I was out for a little drive and heard my front end squeaking. Wondering if I can get a grease needle in there? Most of the front end was done so long ago that I forget what I used, and some of it I know is PU.

Oh, I didn't realize how old this thread was.

Tony I was just updating.