differential cross shaft ? anyone know ?

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Apr 2, 2002 | 09:06 PM

buds

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From: waterdown,ont,canada

differential cross shaft ? anyone know ?

I have a clunking sound when excel. or decelerating. The book says worn diff. cross shaft but does not say what it is. Anyone know? half-shafts maybe?
Thanks

Apr 2, 2002 | 09:10 PM

MikeC

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From: Union Ontario

Re: differential cross shaft ? anyone know ? (buds)

Is it a one time clunk, each time you accelerate or decelerate? or a constant clunking?

It would look into u-joints first.

Apr 2, 2002 | 09:11 PM

Gordonm

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From: Forked River NJ

Re: differential cross shaft ? anyone know ? (buds)

A diferential cross shaft is what holds the spider gears in place. If you do a lot of drag racing or have sticky tires it oblongs the hole and the spiders move around a little. It is rare but does happen. Ujoints are much more common.

Apr 2, 2002 | 09:16 PM

79MakoL82

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From: Palm Harbor FL

Re: differential cross shaft ? anyone know ? (buds)

If it's a one time clunk on acceleration or on decceleration, it could be the front differential mount bushing. MUCH easier to fix than pulling everything apart. Check that first.

[Modified by 79MakoL82, 7:18 PM 4/2/2002]

Apr 2, 2002 | 10:06 PM

Red70

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From: Wellington FL

Re: differential cross shaft ? anyone know ? (buds)

My bet is UJoints. I had the same clunk.

Apr 2, 2002 | 11:00 PM

R. Bruno

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From: San Francisco, CA

Re: differential cross shaft ? anyone know ? (Red70)

I will wager a beer that it is the front bushing on the differential. Easy and cheap $20 fix. You will have to drive to San Francisco to collect the beer if I am wrong though. :D

Apr 2, 2002 | 11:06 PM

buds

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From: waterdown,ont,canada

Re: differential cross shaft ? anyone know ? (buds)

I already replaced the u-joints, guess I'll check the bushing first. (down on knees) please please please be the bushing.

Oh ya...say im doin 40mph and get on the gas...off the gas...on the gas...off the gas...I hear clunk...clunk...clunk :crazy:

Any other thoughts before I gits dirty? :cheers:

[Modified by buds, 9:20 PM 4/2/2002]

Apr 3, 2002 | 12:13 AM

74vetteman

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From: Calgary

Re: differential cross shaft ? anyone know ? (buds)

How many miles are on your car? When I changed my rear gears, I found my differential cross shaft (technically known as the pinion shaft) had oblonged my posi case. There are two fixes for this. Either get a new posi case ($$$) or take a cross shaft from a 12 bolt rear, which is larger, and have a machine shop bore your posi case out to accept the larger shaft. Of course this means that you will need the 12 bolt spider gears.

The benefits of going this route is that your posi will be stronger. Also while you have everything apart, you can file down all the openings (get rid of forging marks etc.) on the posi case to eliminate the chance of cracking. The case usually cracks from the largest opening to the cross shaft bore. If your case is cracked, it is toast.

I got all my parts from http://www.tomsdifferentials.com

If you need more info or have any more questions, just ask and I will dig up more specific info on this procedure. Tom's sent me a pamphlet on tuning the posi etc.