I've got a 10 bolt posi in my '69 which has just been restored. I took it out for its first drive today & found that once the car had warmed up, if I took a sharp turn at very slow speed, like pulling out of a 90 deg junction, the rear axle makes a horrible clunking noise. It's even worse if you reverse it. Is this normal that they should make this noise? Is there anything to quieten it down? Any advice appreciated, cheers....Nige

If you search on "posi clunk" you'll find quite a few posts(some mine). In many cases adding the correct GM posi additive magically makes the bad noises go away. It did in my case. Good luck!

Also make sure your U-joints are tight and did not loosen!

The GM additive should fix the problem. It might take a little while for the additive to get into the clutches, so don't expect it to be fixed right away.

Thanks for the advice guys it's appreciated. The axle was recently filled with new oil (for a posi) before it was driven, after the car was restored. The car had stood for a few years in a garage prior to me buying it, so maybe the cluth packs seized due to this?? How much additive should I add put in it without causing the posi to not work properly? Cheers......Nige

Try driving figure 8's in a parking lot somewhere that will exercise the posi and help get that additive distributed, mine was a little noisy too after rebuild and I was advised to try this and it worked.

One bottle of oil additive is enough most of the time. If you had an Auburn then you would need 2 bottles.

Just wondering which posi do you have?

In NZ we cant get the Goodwrench additive, or GM (US)
Some guys use the GM aussie additive with good results....hearsay.
I and others I know, use the redline posi oil....read the labels carefully some Redline oils bottles have it added, others dont.
Using the 'already added' oil we have add to add 1 extra bottle of Redline additive

A couple months ago a Friend wa in the states, and was going to bring back a couple bottles of GM additive...dont know what was up but they tried to sell him some type of stuff in a aersol can...he didnt get it cause he could not fly back with it.