I Need help with rear end knocking noise
 

I searched the post but could not find any help with my truck rear end problem. The rear end started this loud thumping/knocking type noise. I put on jack stands, started the engine and put it in drive. With the rear wheel spinning I was able to pin point the location of the noise. Its the 1981 C10 orginal factory non-posi rear end. The oil level is good, however I did notice the rear pinon yoke had a small wobble while the rear wheels spinning. Is it possible the front and rear pinon bearing is worned out and the wobble is causing the noise?

Any assistance will be helpful

Thanks

Re: I Need help with rear end knocking noise
 

If you have a noticable pinion wobble, there is a bigger problem lurking. If the pinion is loose enough to move at the yoke end, it has definately damaged the ring gear's teeth too. There is a very precise alignment required with these parts and any "movement" causes improper wear. It will be noisy and the normal rate of wear is greatly accelerated.
Over-all not an easy fix. Simply replacing the bearings (assuming that this is the original problem) will not cure it.

Re: I Need help with rear end knocking noise
 

your pinion nut prolly backed off and chipped some teeth off the ring gear. if you grab the pinion flange can you move it at all? Like its loose? Either way, pull the cover and look inside.. 3 quarts of 80-90 gear oil and a gasket is cheap enough.

Re: I Need help with rear end knocking noise
 

Spudz and Long Hair

Thanks for your prompt reply and valuable information, Base on your feedback and my limited mechanical knowledge Its probably a good idea for me to replace the Rear end. My Local cash of clunker salvage yard currently have a desent selection of C10 pickups. Since I am going to replace the entire unit I may as well look for one with posi-traction because most parts their are sold at a very reasonable price.

Thanks again

Re: I Need help with rear end knocking noise
 

before you do that.... make sure that you dont just have a bad u-joint. if it was a rear ujoint it may look like its the pinion joke moving.

Re: I Need help with rear end knocking noise
 

Hay guys, just my 2 cents and a quick thought. IF the pinion is loose enough for you to see it wobble the the pinion seal should be leaking like crazy. I think Spudz is probably right. "U" joints fail a lot more often than rear ends do. jim

Re: I Need help with rear end knocking noise
 

I've had a knocking sound i thought came from the rearend it was an exhaust leak. hope this will help.