I am going to install a posi and want to know if I should go with a 30 or 33 spline unit or stay with the stock 28. I have 187,000 miles on the axles and new ones with new bearings won't hurt. I got a T/A performance rear end girdle as a graduation gift that I am going to install as well. I expect to shock the rear end hard when I get the engine back together with my build up.
Thanks for any input.
Zack Willett
I believe you will only find spools in 33 spline, not differentials. So 33 is probably out unless this will be a 100% race-only car.
If you go with 28, you could stick with the stock axles. For what its worth, NHRA rules require aftermarket axles at 11.99. (Though most don't heed this) However, if you're buying a completely new carrier and all anyway and don't mind the cost of the axles (I'd suggest Moser, Strange, or another good aftermarket source), I'd go with the 30's.
Scott
My 87 GN, 71K miles, is not posi. I would like to learn from someones personal experience of installing a posi unit in a factory peg leg car, and what kind to consider. I have read references to the Aubern and Eaton posi, and picked up info on the Powertrax at the Nats. I have read many posts in the archives, but I am looking for some solid info and direction for my car mods.
My car was bone stock (have owned for 1 year) until I just added the K&N, THDP, and Hooker exhaust. I am doing the fuel pump, 38# inj, and chip next. I am very happy with the performance results so far, but definitely know I need posi or maybe a passenger side air bag setup at this point. Thanks, Tim Roark
I went with 33 spline axles (Moser)and a spool. I think you can get a posi for the 33's. I would call DTS in Centerline, MI and ask them for their advice. They sell the parts, setup axles and are very knowledgable. Which ever axle you pick, get C-clip eliminators for your own safety (and piece of mind).The C-clip eliminators will force you to remove your parking brake hardware.
Dave
I moved Kurt's question to:
Noise on Decel
to get a better discussion on his possible problem.
I Have a bone stock 87 gn. Was going to install posi unit on my car but not for sure what to get. I have a few questions I would like people to anwser for one. Is a stock axle a c-clip axle? Is a 28spline unit the only size spline I can uses on stock axles? what kind a posi unit should I get? And would I be able to install it my self. I have change a whole pumpkin but have not taken one apart. If someone could answer my questions it would be greatly apretiate it.
28 spline, C clips ...
Eaton makes a really good posi for stocker. You don't change the pumpkin, you basically take the center section out, bolt your stock gears back on the new unit, press on new carrier bears, reset the backlash (probably not necessary since you're using your original gears), and check the preload.
You can do it yourself, but it's kind of a nasty job. After doing it once, I found a place that would do it for $100 and figured it was worth it!
Ditto what Ken said, I found a place that said $125 (to swap in a new eaton and moser axles) and I jumped on it. They spent half a day on it, but better them than me.
28 spline moser replacement axles (C-clip) should be fine for an 11 second car.
Not being very fimilar with posi or really any of the third member heres the question. I looked at the summit catalog and found a 30 spline that says it is for 8.5" for 89' and up GM cars. If I get new axles and bearings will this fit? I want to add posi and while I am at it I might as well go with the up grade in axles as well. I have quit alist of improvements that I want to do but I do not want to have to go back and do something again. Unless I tear it up having fun! Thanks for info.