GM 12-Bolt Advice Needed

[Ol'Jim]

My bracket race car is a 71 Monte Carlo 408 BBC with T-400 & 12-Bolt Rear. Eaton Posi unit, with Richmond 4.10 gears. Heavy Car, (3750# without driver), fairly mild combo. (12.30 @ 108, 1.71 60').
Problem: Broke a Spider Gear (pinion Gear) last season, which trashed pretty much all internal differential parts. Replaced posi with identical unit, which was in very good condition. New R&P gears, bearings, etc.
10 races later, (72 passes), I was pulling routine maintenance, and Cross-shaft in Posi unit is severely galled, as are the spiders that ride on it. Had been using synthetic 75W90 oil for years, when I repaired it last year, Richmond suggested petroleum-based 85W140 instead. The cross-pin is very poorly lubricated, but this is incredible how bad it got chewed up, and how quickly! Okay, 3 questions:
1. What caused this rapid failure? Cross-shaft was "Yukon" brand - could be Chinese sh!t metal?? Or weak clutches in posi, causing single-spin?
2. I cannot get the cross-pin out, I beat on it for almost 2 hours, and it is halfway out of the housing. So I cannot remove the axles, or the carrier. Do I need a cutting torch to get this shaft out? Or?? Anyone had similar experience?
3. Pretty-much decided to go to a spool. I have some GM axles with C-Clip Eliminators on them. But no installation instructions. I am told I have to cut the ends off my axle-tubes? Anyone done this before, or have some instructions on what I need to do to use these? Looks like the bearing retainers are split in 2 halves, do I sandwich the backing-plate flange between the 2 bearing blocks?
Thanks in advance for your help.
-Jim.

[500]

Get some aftermarket axles. You are turning a damn fast time for such a heavy dog. With the spool and the high weight the axles will be taking a beating any time you turn the steering wheel. The axle supplier will be able to suggest the best way to retain the axles.

Take a 1000 lbs off that thing and it will be a lot faster and easier on parts in the bargain. I had a 78 camaro that weighed 2600 lbs without the driver. The only fiberglass was the lift off hood. Windows rolled up and down. Stock windshield and back glass. 6 point roll bar.

Door guard beams 25+ lbs ea

Roof inner steel liner 35 lbs. ,etc.

Ran 12.63 best with a 4.88 [ way too low. 4.10 would have probably run 12.40 ] std bore 350, 600 holley, performer intake, cam dyn 228 @ .050 hyd, std cast flattops. 1.92 & 1.5 valves. Ported dbl humps. Hood scoop blocked off. Had to fight like crazy to slow it down to the 13.00 index.

[Ol'Jim]

500 Thanks for the reply.
I do have Moser alloy replacement axles that are in the car now, I will have the C-Clip nubs ground off, and mount the C-Clip Eliminators on them. I am concerned that the elims will change the position of the axle flanges. Right now I have 10" wide wheels, 11" wide slicks, which have about an inch clearance on the inboard sides, and barely 1/2" outside clearance within the wheel opening of the 1/4 panel.
A friend is coming over today to cut the posi cross-shaft out with a torch so I can remove the axles & carrier.

[blownS10blazer]

Originally Posted by Ol'Jim

3. Pretty-much decided to go to a spool. I have some GM axles with C-Clip Eliminators on them. But no installation instructions. I am told I have to cut the ends off my axle-tubes? Anyone done this before, or have some instructions on what I need to do to use these? Looks like the bearing retainers are split in 2 halves, do I sandwich the backing-plate flange between the 2 bearing blocks?
Thanks in advance for your help.
-Jim.

I am in the process of installing c-clip eliminators on my 12 bolt truck axles and have already cut my housing tube ends. Not hard at all. I have instructions for both 12 bolt car and 12 bolt truck from Moser. If you want, send me an email and I'll email you the instructions.