[amaksoud]

Hello,

My car is 2009 320i automatic transmission woth 77k Km on the odometer.

When slowing down in a turn or approaching a traffic congestion then trying to pick up on same gear at a lower speed, the car doesn’t pick up the appropriate gear until I press the gas pedal a bit harder and it will vibrate from behind until the desired press to pick the lower gear is achieved.

The vibration is from behind not from the engine and it feels like running over and extermly uneven ground.

Any ideas what is this ?

[Bimmer Pleaser]

Does it vibrate when you need torque at a non zero speed? Aka, does it vibrate when you apply gas after coasting for a while?

[amaksoud]

It vibrates as while I’m slowly applying gas until it picks up the lower gear (more torque) so yes is my answer

[labrador]

Does it do that from a stop?

When was the last time rear differential fluid was changed?

[Bimmer Pleaser]

Originally Posted by amaksoud

It vibrates as while I’m slowly applying gas until it picks up the lower gear (more torque) so yes is my answer

Had a similar problem on my e92 which was fixed by changing the tranny fluid.

[amaksoud]

Sorry for the late reply,
@labrador, no, only while coasting and trying to slowly pick up spead
I bought it second hand a few years ago and I guess it was never changed

So we have one vote for the differential fluid and one vote for the tranny fluid. I guess I’ll try the diffrencial fluid first as it’s much cheaper.

Any recommendations on other parts to service while changing the tranny fluid ? Filter, cooler, etc ?
The car has almost 77K KM on the odometer and the tranny fluid was never changed I guess

[e90yyc]

Originally Posted by amaksoud

Sorry for the late reply,
@labrador, no, only while coasting and trying to slowly pick up spead
I bought it second hand a few years ago and I guess it was never changed

So we have one vote for the differential fluid and one vote for the tranny fluid. I guess I’ll try the diffrencial fluid first as it’s much cheaper.

Any recommendations on other parts to service while changing the tranny fluid ? Filter, cooler, etc ?
The car has almost 77K KM on the odometer and the tranny fluid was never changed I guess

If you want to do it right, drop the tranny pan, replace the filter, then seal it back up with new gasket and bolts. You could replace fill and drain plugs too if you're feeling hardcore.

Easier option is just to drain and fill, but the consensus here seems to be that it's worth replacing the filter too.