[djbradle]

I notice this every time now as I turn off the engine and walk around the back of the car and the rear diff makes this click sound. :dunno:

 

[Kubica]

When's the last time you changed the fluid?

 

[ferngreen 325xi]

Are you sure it's not the exhaust flap closing ?

 

[djbradle]

Rear diff fluid hasn't been changed since I owned it in early '09. Didn't know there was an exhaust flap near the rear that closes up . . Almost sounds like a spring and click sound . . like an actual spring closing type of mechanism. I checked the ATF today and it's quite dark brown. Auto of course. I assume the front diff shares the same fluid reservoir as the tranny?

 

[SamDoe1]

None of the drive train components share the same fluid reservoir. What you are hearing is likely the exhaust flap closing. Replacing ALL of the fluids is a good idea to do ASAP.

Good luck!

 

[Kubica]

Are you sure it's not the exhaust flap closing ?

If so, remove the whole flap with a hammer and chisel. One good whack should do it. Golf tee mod is only half of the solution.

 

[tour(ing) de pantz]

doesnt the flap default to open?

 

[SamDoe1]

doesnt the flap default to open?

Yes, but it closes when you start the car.

 

[tour(ing) de pantz]

I notice this every time now as I turn off the engine and walk around the back of the car and the rear diff makes this click sound. :dunno:

as the engine is turned off it no longer has vacuum and cant keep the valve closed. and either way if it was moving slow enough to have not opened fully by the time you get to the back of the car its probably moving slow enough not to make any perceivable noise... my vote is not on exhaust flap...

 

[djbradle]

Yea, definitely the exhaust flap. Looked inside the medial exhaust tip and saw the flap closing making the sound that I had heard for a while. Maybe a little lithium grease around the flap to keep it quiet. Thanks for all the feedback everyone. Still gotta change the fluids though. :thumbup:

 

[djbradle]

I'll be sure to remove if it fails in the future. Maybe the vibration in D and R while idling could be caused by that flap somehow? Probably not.

 

[TxZHP04]

I checked the ATF today and it's quite dark brown. Auto of course. I assume the front diff shares the same fluid reservoir as the tranny?

Uh, there's no reservoir for transmission or diff fluids. The reservoir labeled ATF is your power steering fluid....

 

[tour(ing) de pantz]

well... foot, mouth, mouth, foot... they know each other! hahaha

 

[djbradle]

Uh, there's no reservoir for transmission or diff fluids. The reservoir labeled ATF is your power steering fluid....

Indeed . . my apologies =)