rear diff noise slack?

michael owen · 10-15-2009, 03:13 PM

I have a 1990 Sammi, with 70,000K on it. It has been pampered. It is like new. On my last hunting trip and only while going down hill slowly, with little engine pressure one the drive train, my read diff started a small clunking sound. I could not hear it under a load, only when allowing the vehicle to be in gear but going down hill. My Sammi dealer is unsure. Do I need a new rear seal? a new bearing? I removed the drive shaft after testing in the bush with the drive shaft on and the vehicle in neutral,and by turning the yoke from the rear diff, there clearly is about 1/4" to 3/8" of back and forth play, back and forth as in rotation. fore and aft is tight. There is a small sign of oil seepage from the diff. I tow my Sammi with my truck. Is this an issue to be concerned about? Do any of you have a recommendatio. Reside in Vancouver BC Canada Thanks

ack · 10-16-2009, 04:55 PM

Unfortunately, the only way to find out where the slop is to take it apart.

Since the play is axial as opposed to in and out, I would suspect gear wear. The side gear adjusters are fixed in place with a locking tab, so I don't think the ring gear has somehow backed away from the pinion gear. That leaves plain 'ol surface wear on the pinion and/or ring gear.

I think the dealer is trying to gently brace you for a bite out of your wallet.

The only way to avoid the dealer cost of repairing the differential is to take it apart and fixing it yourself/having a mechanic experienced in differential work fix it for you. Working on and setting up a rebuilt differential is a tedious chore even when you know what you are doing! That is what makes it a pricey repair.

For an interesting tutorial on differential rebuilding, check out this link:

Samurai to Sidekick gear swap. - Zukikrawlers

my996duc1 · 10-19-2009, 11:22 AM

I have abou that much play and the clunking when first letting out the clutch sometimes.... I was told it was because of the locker.
Any chance you have a locker and it is normal ?

Billjohn · 10-19-2009, 06:43 PM

Quote:

Originally Posted by my996duc1

I have abou that much play and the clunking when first letting out the clutch sometimes.... I was told it was because of the locker.
Any chance you have a locker and it is normal ?

Locked or stock, you use the same backlash. And that is the only variable when putting everything back together. A locker won't add slack.

my996duc1 · 10-19-2009, 07:14 PM

Quote:

Originally Posted by Billjohn

Locked or stock, you use the same backlash. And that is the only variable when putting everything back together. A locker won't add slack.

wow, good to know.
Petroworks installed the Rear Detroit locker and told me I would have slack, which I do....

chevy4x48586 · 10-20-2009, 07:37 AM

i have the same problem. I get a clunk when i let out the clutch, and when i looked underneath there was a little oil leak at the yolk. Also there is play left to right etc in the yolk. I was told it might be the pinion bearing/seal and when i looked into the fix i decided if thats the problem it was time to look for tracker 3rds to swap for the 5:12 gears. Mine is a stock open diff also