Ring & pinion excessive backlash

92 LX

Member
Nov 10, 2004
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The story: '92 LX 5sp 145K mi. 3:55s installed by previous owner pre 75K mi.
Whine at 40-45mph. Lived with it. Now clunking from diff. Changed the clutches in the t-lok, no difference. When I wiggle the driveshaft, I have about 1/4" play, and can hear the clunking. Anyway to add shims to get rid of the clunking? If teardown is eminent, can I save the 3:55s, or should I get new ones? Any particular brand?:shrug:
Thanks!
 
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junkyardwarrior

Active Member
Jan 10, 2011
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don't know. Mine is exactly the same issue. Rebuilt the Tlok no change. I pulled the cover off of mine and the teeth of the ring gear are razor sharp. I assume the gears are worn. Don't think shimming is going to help-well-it might take away the excessive backlash but is that going to put the pinion too deep into the ring gear?

I plan on swapping to a 3.73 soon anyway so I'm going to live with it for as long as I can stand it.
 

NIKwoaC

中國製造
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Oct 31, 2006
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Chengdu Province
My worry about shimming is that the gears have already developed a wear pattern with each other. Shimming will put the gears out of alignment with that wear pattern, and then they'll probably continue to whine like that until they develop a new wear pattern, if they even ever do develop a new pattern, which they may not. The damage is already done, the teeth are already deformed, the gears may not be salvageable, BUT you won't know unless you try, know what I mean?

Unfortunately, the RIGHT answer, and probably the answer you will get from a lot of shops, is that you should install a new gear set. This time with proper shimming and backlash.
 

ratio411

Founding Member
Apr 21, 2002
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Pensacola FL
Have you actually checked the backlash?

.015" at the ring feels much larger at the driveshaft.
And the gears are sharp when they are brand new. That is not an indicator.
 

ratio411

Founding Member
Apr 21, 2002
3,870
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Hang on...
When you "wiggle" the driveshaft and get a clunk, are you rotating it, or is it moving up and down?
Pinion bearings worn out will whine and clunk. At that point they will also wiggle a great deal at the shaft.