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-   -   323i Shifter Vibration in 1st (http://www.maxbimmer.com/forums/showthread.php?t=157637)

m_guimont323 05-14-2013 02:51 PM

323i Shifter Vibration in 1st
 
Hey guys,

So I recently noticed that under heavy acceleration in 1st gear, there is a very audible and noticeable vibration being emitting from the shifter. The shifter has been replaced with an aftermarket unit (no rubber isolator a la OEM).

Conditions:

Any hard/heavy acceleration in 1st gear. Symptom does not appear in any other gear or on deceleration. The vibration also seems to only come through the shifter and not the body or any other components.

The car has seen some heavy use in track circumstances and has roughly 270 000 km on the engine and transmission and drive line components.

Recently Replaced:

2 X engine mounts (with M3 mounts)
2 x trans mounts (with M3 mounts)
Rear Subframe reinforcement kit
Poly subframe bushings

Thoughts:

My 1st impression is it could be a tired bearing or gear inside the tranmission causing 1st gear to misbehave, however that has been no other issues with other gears or any problems wit the car jumping out of gear/grinding.

Could it possibly come down to the driveshaft "guibo" or rubber disc gone bad ? Any insight here is appreciated.

Thanks !

cormier 05-14-2013 03:21 PM

I would think tranny. Guibo would be in all gears, as would most driveline parts

jabela 05-15-2013 01:19 AM

I was gonna say mounts, but maybe you want to inspect them to make sure they're secure.
I've seen where engine mount extension has broken, also where the transmission mount bracket has broken.

I also have M3 engine and motor mounts. I do get slightly more vibration, but only between 800-1000 rpm. I have a stock shifter though.

It could still be the guibo... just that certain vibrations with more load in first gear maybe? kind of a stretch, but worth looking if the guibo has never been replaced.
I'm at 180k and my guibo is cracked. i have a new one ready to go in soon.

What about on heavy high rpm engine braking in 1st gear?

jabela 05-15-2013 01:20 AM

Maybe the clutch going bad? Has it ever been replaced?

m_guimont323 05-15-2013 06:30 AM

The mounts only have about 2000 km's on them. But there is a good chance that maybe some damage was done prior to them being replaced.

I have noticed the increased vibration from 800-1200 rpm you mentioned, that doesn't bother me and i'm assuming is just resonant frequencies from the stiffer mount set.

The clutch is an unknown for sure... it has never been replaced by me.. and i've had the car since 192000 km. I would assume if it was the clutch that it would affect all gears.

Finally, under heavy engine braking (i.e. hard accel up to redline in 1st, release gas, there is no odd vibrations, it only seems to be under accel)

Thanks for the all the good points though, I'll take a look into the tranny mount and guibo when I can get under the car next.

cheapthrills 05-15-2013 08:14 AM

It could be that some part of your aftermarket shifter is hitting the guibo or driveshaft. Did this problem start just after you put in the shifter?

Hard acceleration in 1st is when the driveshaft transmits the most torque, thus the most twisting of the transmission and motor mounts occurs then. Guibo failure will show up under hard acceleration in 1st before it is noticable in other gears. However, you'd notice the whole car shaking, and you said it's only in the shifter.

Get under the car and note where all the shifter parts are in each of the gears using an inspection mirror.

Two possible solutions would be to install a different shifter, or install poly motor and trans mounts. In my E30, poly trans mounts make the cabin very loud.

cormier 05-15-2013 09:42 AM

I should have thought of guibo interference, it happened to me

What does your selector rod look like? Any different?


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