Hello,
hope this finds all of you well. I was driving in my 2000 996 C4 ( just shy of 96k miles) when I heard a thud which looking back was probably the bearing breaking. I originally thought I hit a pothole or something in the road but there was nothing when I went by the same spot again. Drove for a few miles and it started to drone loudly like straight cut gearing. Noise started less than 10 miles ago. I’ve researched a little bit and it looks like it could be pinion or carrier bearing failure. Had the clutch and flywheel replaced less than 100 miles ago so I was wondering if you guys think that could have in any way caused this or if it’s just age. Also, if any of you have had similar issues a rough estimate on price would be immensely appreciated. Thank you all for your time.

happy cruising,
palmer

 

It's unusual for a bearing to break, per se, and I don't have good guesses as to the origin of the thud. The droning could certainly indicate a bearing failure. Does it happen in all gear? Does it happen on both accel and decel (braking)? Have you localized the noise to the transmission, or could you for example have a bad wheel bearing?

 

If you had drivetrain work done 100 miles ago, I would go back and ask for the mechanic to look at it again.

 

Check your Axle bolts ASAP !!!! My gut tells me that the Axles were not properly torqued.......Mistakes happen but don't drive it untill you check that the Axles are tight...

I have seen it happen a few times and the Thud you heard plus now the drone are symptoms of a loose Axle,...... Next is the Axle coming comply detached that could cause more damage or even be dangerous....

 

turns out it was a broken motor mount. Or atleast that’s one of the issues. If the motor mount doesn’t solve the noise I may as well see how well a 996 works as a submarine