Just joined? Please introduce yourself.
Page 7 of 8 FirstFirst ... 5678 LastLast
Results 61 to 70 of 71

Thread: Suspension Bushings - Delrin, Rulon or Other

  1. #61
    Registered Member
    Join Date
    Apr 2012

    Member #:571
    Posts
    4,671
    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.
    Last edited by Rick_L; 02-19-2017 at 05:49 PM.

  2. #62
    Registered Member
    Join Date
    Feb 2014

    Member #:2084
    Location
    Laramie, WY
    Posts
    92
    Quote Originally Posted by oceangoer View Post
    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.

  3. #63
    Registered Member chevynut's Avatar
    Join Date
    Nov 2011

    Member #:115
    Location
    Fort Collins, CO
    Posts
    10,835
    Quote Originally Posted by oceangoer View Post
    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/ure...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.
    56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension


    Other vehicles:

    56 Chevy 2-door BelAir sedan
    56 Chevy 210 4-door sedan
    57 Chevy 210 4-door sedan
    1962 327/340HP Corvette
    1961 Willys CJ3B Jeep
    2001 Porsche Boxster S
    2003 Chevy Silverado 2500 HD Duramax
    2019 GMC Sierra Denali Duramax

  4. #64
    Registered Member chevynut's Avatar
    Join Date
    Nov 2011

    Member #:115
    Location
    Fort Collins, CO
    Posts
    10,835
    Quote Originally Posted by hutchenc View Post
    (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.
    56 Nomad, Ramjet 502, Viper 6-speed T56, C4 Corvette front and rear suspension


    Other vehicles:

    56 Chevy 2-door BelAir sedan
    56 Chevy 210 4-door sedan
    57 Chevy 210 4-door sedan
    1962 327/340HP Corvette
    1961 Willys CJ3B Jeep
    2001 Porsche Boxster S
    2003 Chevy Silverado 2500 HD Duramax
    2019 GMC Sierra Denali Duramax

  5. #65
    Registered Member
    Join Date
    Apr 2012

    Member #:571
    Posts
    4,671
    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.

  6. #66
    Registered Member
    Join Date
    Feb 2014

    Member #:2084
    Location
    Laramie, WY
    Posts
    92
    Quote Originally Posted by chevynut View Post
    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
    Last edited by hutchenc; 02-20-2017 at 11:26 PM.

  7. #67
    Registered Member NickP's Avatar
    Join Date
    Mar 2012

    Member #:1653
    Location
    De Queen, AR
    Posts
    4,157
    An update, not complete yet. A couple more features to figure out.


  8. #68
    Registered Member NickP's Avatar
    Join Date
    Mar 2012

    Member #:1653
    Location
    De Queen, AR
    Posts
    4,157
    Added Snap Ring Grooves and center channel to reduce weight.

    Link-C4 v2 v9.jpg

  9. #69
    Registered Member NickP's Avatar
    Join Date
    Mar 2012

    Member #:1653
    Location
    De Queen, AR
    Posts
    4,157
    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.

  10. #70
    Registered Member
    Join Date
    Nov 2015

    Member #:2764
    Posts
    649
    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.
    Last edited by 55 Tony; 02-22-2018 at 05:15 AM.
    Tony

    1955 Bel Air Sport Coupe

Page 7 of 8 FirstFirst ... 5678 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •