Asking for feedback on my web site and my new CNC machined axle bearing retainer plates

[enigma57]

The determining factor for me is the overall strength of the rearends in these cars. I have built several '55s and a '56 priour to the '57 I now have. '55 and '56 had weak axles and rear wheel bearings. I wiped out several right rear wheel bearings and twisted a couple of right rear axle shafts in my '55s and my '56 before changing out the rearends for stronger units.

'57 had stronger axles and larger/stronger wheel bearings compared to '55 - '56 but '58-up wheel bearings are stronger than '57 and there were upgrades to 3rd members from '59 through '64 as vehicle weight and horsepower increased.

In my experience, 300 HP (measured at the flywheel) is the max I would consider putting through a stock '55 - '56 rearend and that would be with the understanding that stock wheel bearings would not last as long and I would definitely paint a white stripe down the length of at least the right axle shaft and pull it from time to time to check for twisting.

A stock '57 rearend, I would trust to take around 350 HP under the same conditions except I would not worry as much about rear wheel bearings and twisting axle shafts.

That said...... All my '55s, my '56 and my current '57 have been stick shift cars. I have never owned one of these cars with an slush box and never intend to so long as my left knee doesn't go out entirely. If I were running an automatic, I would up the max HP (measured at flywheel) that I would trust a stock rearend to handle by 25 - 30 HP because of the power lost to operate an automatic and the 7 - 8% power loss through slippage when not in high gear with converter locked up. And unless you have what I would call a race only 'shift kit' that slams an automatic transmission into gear (shocks the driveline) unnecessarily with each shift...... Automatics are generally easier on driveshafts, U-joints and rearends than are stickshifts.

My rough rule of thumb has been to swap in a stronger rear (9" Ford/12-bolt Chevy/9-1/4" Olds/8-3/4" MOPAR) in these cars for any engine exceeding 400 HP and/or 400 ft./lb. of torque.

The exception would be if I decide to beef up the rear in my current '57 (I anticipate right at 400 HP from the small block engine I am putting together now). In that case, I would look at beefing up the stock '57 rearend with an early '60s posi 3rd member, stronger Moser axle shafts and add your '58 - '64 big bearing kit. And since I have always built my cars to handle well in turns, the added strength (rigidity) of your wheel bearing retainer would be a plus for me as far as keeping the axle shafts and rear wheel bearings from moving laterally during hard cornering. I will be in touch when I reach that point.

Thanks,

Harry

[rockytopper R.I.P 5-13-2017]

Good reading Harry. I just purchased a 57 rear to upgrade with new axles, Eaton limit carrier and new everything else to replace the stock 55 rear I have in the mad. The stock ls2 I'm installing is rated at about 325 to 350 at the wheels. I am planning a slush box behind it and will be pulling a trailer and hard corning in AX etc. Perhaps the larger bearings would be worth the extra cost but this will quickly push upgrading a stock rear to 9 inch direct bolt in units prices lol so it makes it hard to justify if we are doing for strength reasons lol.
Personally I shred the pinion gears on 3 of my first 55 rears shifting a stick at WOT with only about 200 hp at the fly lol.....

[Rick_L]

A few thoughts on the stock rear.

The weakest link in these axle assemblies is the spider gears in an open differential. They are all weak, year doesn't matter as that part never changed over the years. The remedy for this is a posi unit.

The 55-56 ring and pinion gear is slightly smaller and weaker than the 57 up gears. Thing is, you can't use them with a posi anyway, and also all the replacement gears on the market are 57-up style.

There is no difference in the strength of the 55-56 axle shafts compared to the 57-up axle shafts. But they are all weak, and are the second weakest piece behind the open style spider gears.

I personally think the smaller 55-56 axle shaft bearings, while weaker, are not significantly so. Leaks are the biggest problem with any of them - it's due to age as much as anything.

[markm]

Ricks comments are why it was cheaper to build a 9.3 for 56 and a Dana 60 or 55, both which use the big Olds wheel bearing. As far as axles go 29 and 35 spline both with Spicer 4 pinion posi units. These units are the 57-64 Chevys posi units bigger brothers. I am in to both for about the cost of a beefed up stocker or aftermarket Ford.

[chevynut]

In my experience, 300 HP (measured at the flywheel) is the max I would consider putting through a stock '55 - '56 rearend
A stock '57 rearend, I would trust to take around 350 HP under the same conditions except I would not worry as much about rear wheel bearings and twisting axle shafts.

I had a 57 rear in my 55 Chevy with a 390 HP 427 in it and never had any problems. It had 4:11 gears and a posi in it, with a 4-speed tranny and I did burnouts with it. I'm not sure what HP has to do with it, since torque is what breaks parts. My 427 probably made a lot more torque than a 350 HP 350. But tires are what limits torque to the drivetrain anyhow.

[markm]

I had a 57 rear in my 55 Chevy with a 390 HP 427 in it and never had any problems. It had 4:11 gears and a posi in it, with a 4-speed tranny and I did burnouts with it. I'm not sure what HP has to do with it, since torque is what breaks parts. My 427 probably made a lot more torque than a 350 HP 350. But tires are what limits torque to the drivetrain anyhow.

Yes, I am sure you are correct about the 427, but wasn't that in the 60s/early 70s on bias ply tires.

[enigma57]

There is a fellow up in Canada who builds 409 cars. Some years back, he had rearend upgrades available for the '64 and earlier Chevy rearends...... Bearing cap girdles and a Dana 44 spider gear retrofit that allowed fitting stronger custom 30-spline axle shafts. Will check with him and see if those upgrades are still available.

OK...... Sent Aubrey an E-mail concerning this earlier today. He says he still offers the rearend upgrade pieces but the Dana 44 spider gear and axle upgrade will only work with the factory type Dana 'Power Lock' posi units. Not on open rearends and not with the newer Eaton posi retrofit units. Moser makes the Dana 44 axle shafts for use with Aubrey's spider gear upgrade in the wider early '60s Chevy rearends. So they could make similar axle shafts for a '57 Chevy with the 30-spline Dana 44 axle and spider gear upgrade.

Dennis' larger '58 - '64 wheel bearing upgrade for '57s...... Along with Aubrey's bearing cap girdles, Dana 44 axle and spider gear upgrade...... Would really add a lot of strength where needed. I was thinking of contacting Moser anyway, as I want stronger axle shafts and have also been toying with the idea of asking them to adjust the wheel mounting flange outboard a small amount so as to allow wider drum brakes to be fitted at the rear. Something I have done several times since 1970, but this would make the wider drum and shoe mod at the rear easier.

If I go this route, will let y'all know how it works out.

Best regards,

Harry

[markm]

Is it still an option to use 8 3/4 Slopar axles and side gears in GM posi equipped cars.

[enigma57]

Haven't tried that one, Mark. The upgrade Aubrey has for his 409 cars uses Dana 44 spider gears installed in the factory Dana posi unit and custom 30-spline axles. That's all I know about it. Got an E-mail from him today. Reason I had trouble locating his rearend upgrades on Mr. Gore's internet was that some jerk in Germany hacked his website in 2014 and he hasn't been able to rebuild it and retrieve lost data since. Wish I could help him with that but I don't know anything about computer websites and such.

Happy Motoring,

Harry

[Maddog]

Be careful with him, he's an ex con