What are the bolt torque specs for the pinion nut and the carrier bolts for a GM 7.5" rear? I posted this on the Transmission and Rear end board and got no responses. Thanks

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89 Transam GTA, 350TPI, auto, 3.27 rear, dual cats, gray.
Magnaflow cat-back,
K&N open element,
Best E.T. 14.63@95mph

 

Carrier bolts are about 60 ft-lbs. Pinion nut doesn't have a torque spec, you should expect something in the 150-180 ft-lbs neighborhood, you torque it for correct bearing preload by way of crushing the crush sleeve which is only good for one tightening. You throw it away and put in another if it's not new.

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"So many Mustangs, so little time..."
ICON Motorsports

 

pinion bearing preload with new bearings is 20-25 in/lbs

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

I replaces the crush sleve and the input seal. The bearings were in great shape. 20in/lbs seems kinda light. Are you sure it's not more like 20-30 ft/lbs.?

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89 Transam GTA, 350TPI, auto, 3.27 rear, dual cats, gray.
Magnaflow cat-back,
K&N open element,
Best E.T. 14.63@95mph

 

The idea is, you torque the pinion nut until it takes that many inch-ponuds to turn the pinion. You're trying to tighten the nut just past the point at which all the play betwen the bearings gets taken up. Like I said earlier, expect something in the neighborhood of 150 ft-lbs on the nut by the time you get the crush sleeve crushed to the right point.

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"So many Mustangs, so little time..."
ICON Motorsports

 

ok, i get it now. Thanks for your help.

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89 Transam GTA, 350TPI, auto, 3.27 rear, dual cats, gray.
Magnaflow cat-back,
K&N open element,
Best E.T. 14.63@95mph

 

I have a 2000 firebird with a 10 bolt rear end and noticed a humming more grinding from the rear end. Ill be honest im morenof a mopar guy and just recently bought it and when i looked underneath itnwas leaking gear oil from the yolk going into the pinion/pumpkin i guess. Theres a gap between the two and the nut looks like its backing out possibly it only has about two or three full threads left. My question is is there a certain distance the nut needs to be tightened for it to sit and align everything in the pumpkin correctly?

 

I think that was covered in the above post.

Problem you may have is, the crush sleeve, which is what the nut tightens up against, may already be crushed beyond the proper point. In which case the only thing holding the nut in place is its nylock feature. If that's how it is, it will never stay tight, until the crush sleeve is replaced. You can try though; pop the axles and the carrier out, and try to tighten the nut until it takes 25 in-lb or so to turn the pinion. The locknut takes probably no more than 25 or 30 ft-lbs to overcome the lock, so if you have to put LOTS of torque on it to get the right bearing preload (like, over 100 ft-lbs), you're probably crushing the crush sleeve, and your odds of success are better.

Make yourself a tool like this to hold the pinion still while you tighten the nut with a long breaker bar and a 1¼" or 32mm socket.



It's about a 3' or 4' long piece of 1½" wide bar stock from the hardware store. Drill the holes near the edge so it doesn't interfere with the socket getting onto the nut.