XLR I FL said:
I am seeing Caly replacing parts in his rear end in lieu of the fluid exchange with positraction fluid so I am waiting for him to report in after he gets his car back next week sometime. Please watch for his posting to see if the problem is gone and if it is the same as yours.
Regards
They did the fluid thing quite a while back... 6-8 months or more, and that did cure the grind-thump thing. No problems until the last month where we started noticing a whine... just when holding your speed, it would go away on excelleration or coasting. They tried to change the parts but ended up changing the whole differential.
Just over 20K miles... it's a daily driver. All under warrenty.
There were no leaks or any abuse/habits/events that I am aware of that may have been the cause... I suppose it was just a scuffed up part new or poor assembly from the factory. Same rear-end as used in Corvettes, so I know they have lots of experience with them and that they can take a load.