Shifter rattle at idle + crazy movement at launch

Developed pretty suddenly, transmission/motor mounts are fine, rear looks fine minus worn mounts and dog bones:

1. Shifter rattles at idle
2. If speeding in first gear, at 4K+ RPM shifter starts to go hard to the right, no sound but with pedal (drive by wire) it feels like teeth are grinding or something (could be road condition)
3. Launching the car in first, shifter goes CRAZY to the right, car shakes violently.

Any ideas? Guibo looks good. No gears pop out, seems to be related to high rpms/launches in 1st gear but shifter does lean to a bit right at high rpm in second gear too.

Originally Posted by E34Addict

Developed pretty suddenly, transmission/motor mounts are fine, rear looks fine minus worn mounts and dog bones:

1. Shifter rattles at idle
2. If speeding in first gear, at 4K+ RPM shifter starts to go hard to the right, no sound but with pedal (drive by wire) it feels like teeth are grinding or something (could be road condition)
3. Launching the car in first, shifter goes CRAZY to the right, car shakes violently.

Any ideas? Guibo looks good. No gears pop out, seems to be related to high rpms/launches in 1st gear but shifter does lean to a bit right at high rpm in second gear too.

1, 2 & 3 all point to the transmission is moving around a lot, which means the motor is also moving around a lot, so it sounds like it's gotta be related to the condition of the motor mounts and/or transmission mounts.

Originally Posted by McSpeed

1, 2 & 3 all point to the transmission is moving around a lot, which means the motor is also moving around a lot, so it sounds like it's gotta be related to the condition of the motor mounts and/or transmission mounts.

I agree 100%, there simply is no other possibility.

Motor mounts are virtually impossible to inspect on the car. Even when removed, typically the only real sign of failure is how compressed they appear next to fresh mounts. Stock transmission mounts can tear but they don't have to be in that bad of shape to need to be replaced.

My shifter rattles as well and when in neutral naturally shifter goes almost all the way to the right instead of being centered .
My shifter doesn't rattle to bad

I checked transmission mounts and they are fresh, engine is stationary when opening trottle in idle.

Could it be flywheel?

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When parked and revving the engine, the engine is essentially free-spinning with no external resistance. Accelerating hard while driving down the road is going to impart far more load on the mounts as there is a force (eg, the tires on the road) acting in opposition to the force of the engine.

No, an unbalanced flywheel will not cause the shifter to move to the right. I can almost 100% guarantee you that you have a problem with the motor and/or transmission mounts.

EDIT: I'm not sure it makes a difference but are we discussing an e46 or an e34 here?

E34, your theory is what I suspected but faulty motor mounts would show sign of failure upon throttle test on the lift... trans mounts are pretty much new. If this is not flywheel, would rear end issues be suspect? (Diff/dog bones)?

I'm not familiar with the e34 but according to realoem the engine/transmission mounts and shifter setup is basically the same as the e46. Pretty much the only way the shifter is going to move substantially under hard acceleration is if the engine and transmission are moving relative to the chassis. This can only happen if the mounts aren't doing their job. Like I said before, they don't have to be visibly torn... just soft enough to deform more than when they were new. The rattle could possibly be coming from the shifter carrier or any of the other various components of the shifter but even play in the shifter itself will not cause large deflections of the shifter under acceleration - that can only come from movement of the transmission and/or engine.

Originally Posted by TxZHP04

I'm not familiar with the e34 but according to realoem the engine/transmission mounts and shifter setup is basically the same as the e46. Pretty much the only way the shifter is going to move substantially under hard acceleration is if the engine and transmission are moving relative to the chassis. This can only happen if the mounts aren't doing their job. Like I said before, they don't have to be visibly torn... just soft enough to deform more than when they were new. The rattle could possibly be coming from the shifter carrier or any of the other various components of the shifter but even play in the shifter itself will not cause large deflections of the shifter under acceleration - that can only come from movement of the transmission and/or engine.

Yeah. The other things to look at are the ears on the front subframe that the motor mounts attach to. These can fail and leave the motor mounts more or less free floating. You'd see serious corrosion or stress cracks below the motor mounts in that case.

Word up homies.