Okay guys, I changed my diff a week or 2 ago after it being really loose and having a big knock all through the gears aswell as the knock from diff it sounded like the tailshaft was rattling around when accelerating, anyway after I changed the diff the knock was gone and now the tailshaft noise is still there. Ive checked the centre bearing and it look fine, also checked the tailshaft bolts but they were tight as.. Anyone know what it could be?

It could be free play in the universal joints

Quote: Originally Posted by TUXEDO [View Post] It could be free play in the universal joints Could they have possibly been damaged by the old diff?

it's the centre bearing, I took mine for a thrash around winton and ever since then it has been knocking, mainly around 3000rpm under medium load. A new one is $25 off ebay, and they're pretty easy to change once the shaft is out

Just replace both uni's and the centre bearing and clean and re-pack the cv joint. Mark every piece of the shaft so you can reassemble it exactly how it came apart to avoid issues with assembly and to avoid putting it out of balance. Or pay a mechanic or driveshaft specialist to rebuild it.