Differential problems

zurud

New Member
Apr 10, 2005
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Evansville, IN
My differential is whining when I am boosting around 15 psi. Lower than 15 psi it works fine. On slow speed making turns, the differential is chattering like I am having a spool. I took it to 4x4 shop since they they are the only place in town that rebuild differential. They took it apart and said everything is fine - clutch, bearings etc. But they didn't measure lash and preload. So I got another differential from 88 turbo that's leaking the pinion seal. I changed the pinion seal that I bought at Autozone. The seal is made of plastic unlike the seal that was in the diferential which is 90% steel and 10% plastic. I really don't know where to get steel seals, probably dealer. I didn't measure the pinion preload since I don't have any inch pound torque wrench. Inch pound torquewrench that start at zero inch is really expensive. I figure I will know pinion preload when I take nut off. I started at 90 ft/lb since the nut is suppose to be torque at 134 ft/lb. When I took the nut off, it come out so easy. It must be torque less than 50 ft/lb. For 30mm nut, it must be higher than that. So I torque down the nut to 134 ft/lb. I reuse the nut. It is off 20 degree from previous stake. I think I put too much preload on the pinion. Its little bit harder to turn the differential now. My question is , what's will happen to differential when I didn't put the correct preload on the pinion?

Thanks
 

Nick M

Black Rifles Matter
Sep 9, 2005
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You will ruin the bearing. Don't ask me how fast, I dont' know. Torque to book specs to avoid this problem. Unless you are talking headgasket. ;)

Chatter and whine are to different things. What do you know about the 4 X 4 shop? I find it hard to believe they inspected it and didn't measure backlash at least by feel or drive it. Whine is backlash. Just like an old siren that is two gears in mesh.

Is there anything else that could be making the noise?