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Bent input flange on an 02 diff

Mike Self

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One of the "ears" somehow got bent in shipping--PO must have dropped the box--and now it's about 4mm bent at the bolt hole. It's a 3.64 LSD so I obviously want to save it.

IIRC if you remove the flange then you have to go through all kinds of rigamarole with a crush washer and some precise torquing or you'll upset the ring and pinion gear settings, and I'm afraid to heat the flange with a torch to bang it out for fear of damaging the input shaft seal.

Any suggestions?



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Id heat it and try to keep the heat localised and maybe a wet rag around the nose of the diff.The seal can take a fair amount of temperature seeing how hot a diff gets when racing.

As you said the other option is removal and resetting the thrust .

You wonder if any other damage was done when it was dropped.

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i have seen this once before. if the drive

shaft is flush for all the rest and the circle on the

shaft sinks into the input flange, then the

three bolts tightened correctly and the fourth

one snugged, and maybe shimmed, it will work

fine. i don't think heat will solve the problem

because once cast iron is stressed it does not

respond well to being reset. you could also make

a cast with epoxy of the exact shim as tightened

and then copy it from steel as a repair.

good luck! let us know the out come.


stone racing co

phila pa 19123

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The flange is not made of cast iron. Judging by the wide parting line (flash) around its periphery, I would say that it is a forging. If it were cast iron it could not have been bent without breaking in the first place. Clamp a Crescent wrench onto it and try to straighten it without heat.

No amount of skill or education will ever replace dumb luck
1971 2002 (much modified rocket),  1987 635CSI (beauty),  

2000 323i,  1996 Silverado Pickup (very useful)

Too many cars.

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A drop hard enough to deform metal of that thickness has probably destroyed the crush washer. Your best bet is to replace the questionable parts. It sucks, but its worse to get it together and realize there is a problem later. It also gives you the opportunity for a proper inspection of the internals.

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Make a plate out of 1/2" steel with the four holes to match then bolt that plate on and draw the offending section into alignment. You can put washers between the correct three and the plate to allow the fourth to draw in enough to spring back. If you don't own a dial indicator, now is your chance.


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try to straighten it without heat.

this would be my first try, too-

gently. Those flanges aren't all that durable, I've had several bent ones.

It's not all that hard to replace the crush sleeve- yes, you have

to pull the carrier, and press the pinion apart, but there's no reshimming or anything

involved. Just the preload setting, and that's approximate

(as in, a bit snug always works)

You get a new pinion seal that way, too.

But I'd try straightening it first, then make sure the pinion nut's still way snug-

if it turns with less than something like 50 ft- lbs, then the sleeve's been

compressed some more.

Those things are HELLACIOUSLY stiff, so it takes a goodly amount of

force to compress them- less than an oblique hit to one ear.

But I'd straighten the ear- the flange will deform if you don't.

Fortunately, that stuff's pretty overbuilt for what it does.


"I learn best through painful, expensive experience, so I feel like I've gotten my money's worth." MattL

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