Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Rearend clunk
Thread: Rearend clunk
View Single Post
  #4 (permalink)  
Old 07-19-2005, 04:30 PM
DoubleVision's Avatar
DoubleVision DoubleVision is offline
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,658
Wiki Edits: 0

Thanks: 15
Thanked 60 Times in 57 Posts
Since this is a factory posi, did you add the GM limited slip differential lube? if you didn`t the rear will make all kinds of pop and clunking noises, usually the noise doesn`t show up until the rear diff gets hot. If you used standard gear lube you`ve found the problem. You can get about a 4 oz bottle from any GM dealer, or you can upgrade to a synthetic lube like royal purple which doesn`t require any anti chatter additive. Most factory posi`s had a tag on them that said "use GM limited slip differential fluid only" most people don`t know what the term "limited slip" means, so they add standard fluid. I`ve seen people in the past have the rear replaced because of the chatter, not knowing all they had to do was add the fluid. I had a 79 Z28 with a posi, the car sat 9 years and the rear chattered like crazy, I added the parts store additive that said it elimated chatter, it did no good, I added the GM additive, problem solved. In my Cutlass that I have now, I installed a posi diff, added royal purple lube alone, no chatter problems.
Reply With Quote