6-spd Manuel Transmission - Gears Rattle [Archive] - Bimmerfest - BMW Forums

: 6-spd Manuel Transmission - Gears Rattle

03-10-2005, 01:06 PM
For the X3 stick drivers. Have you guys noticed that when shifting from 1st to 2nd that the gears rattle? This only happens when you step on the clutch while the rpm is falling. Example: In first gear 3k rpm, ease up on the gas and let the rpm drop to 2k . While the rpm is dropping engage the clutch. Every time I do that it causes the gears to rattle. When i say rattle i mean the gears make a rattling noise. I talked to the dealer and they said its normal. I've never heard the gears rattle in the 330i or 530i. Anybody experience this problem?

03-10-2005, 01:26 PM
I've never heard my gears rattle. Not sure i believe your dealer. Is there another one close by you can go to?

05-07-2006, 01:41 PM
Yes, I am hearing exactly the same thing in my manual X3, as well. Did you get it sorted out?

05-07-2006, 05:38 PM
Hmm - not hearing anything like that in mine at all.

05-07-2006, 06:58 PM
Yes, I am hearing exactly the same thing in my manual X3, as well. Did you get it sorted out?

I found out that it is actually normal on BMW manuals. I was looking through e46fanatics.com and alot of the guys there has that issure w/ their manuals. BMW saids it is normal, this is what they said on that board.

I***8217;m with BMW of North America, LLC. The M3 is a refined version BMW***8217;s race cars. It is designed to provide optimum power and performance in a street legal package.

In order to transmit engine torque to the rear wheels instantaneously, without any time lag, the whole M3 power train was designed with maximum torsional rigidity. To achieve this maximum torsional rigidity, the flywheel mass and its damping capability has been reduced to a minimum.

As a result, during an abrupt torque transfer (e.g. 1st to 2nd gearshift at low engine speeds) the driver can receive an acoustic feedback, which can be interpreted as a ***8220;clunking or rattling***8221; noise.

The acoustic feedback characteristic is not a symptom of a failure, and does not compromise long-term reliability of drivetrain components (clutch, transmission, differential), nor does it adversely affect performance of the vehicle.

If you have any questions, you can phone us at 800-831-1117.

I was in my friends 330i and he also has that issue when the rpm is dropping when he engages the clutch.

05-08-2006, 02:23 PM
Thank you, good to learn something new!
There's not a great deal of engine torque to transmit in our European spec. 2.0i X3...;)
But it's still fun to drive!

05-09-2006, 05:59 AM
Sorry, but I am not hearing a gear rattle in mine. What I do hear is some differential whine that is only audible under neutral deceleration...

12-16-2010, 01:18 PM
Well - I have the rattle but with some fancy footwork, I am able to prevent it - releasing the throttle just right before disengaging the clutch.

on the other hand...we also have a clunk - that happens while riding in gear. usually after about 3 or 4 seconds. granted we are past 100K now on an 04' 3.0. the mechanic is telling me the transmission is noisy using "chassis ears". the problem is suspected to hopefully be clutch related but if not, its the tranny - and they DO NOT rebuild those things.

thoughts? comforting words?

12-17-2010, 08:00 AM
"Acoustic feedback"? Great response, I love it!:D

12-17-2010, 08:19 AM
comedy is always appreciated. well - we got the X back today - we held off on the deep dive since we were getting some other service. when the wife got home i checked the tires. we have one mis-match on the front left and the tire pressure is was all over the place - and extremely low. funny the mechanic didn't take care of the tire pressure as standard practice.

anyway - i set the pressure equal on all tires - on the firm side - and guess what? aside from once when I initially drove off, i could not notice the clunk again. hmmm. only a little shimmy. you can best believe i will go for a set of tires before a transmission any day - that wouldn't fix the problem. they are getting low anyway - especially the odd-ball tire. hmmmm...

the mechanic is researching anyway around the transmission (parts / pricing / availability). if the tire's fix it, i am may test him a bit to see if he found any other possible cause. then i can decide how much i really trust his ability or him in general to go for the solution vs. the $$$$$.

12-19-2010, 02:36 PM
I always thought that sound was the clutch disengaging when I was less than smooth with my footwork. And btw releasing the throttle a tad just before shifting is a very good way to drive smoothly I find -- which is something I entertain myself by trying to do.

12-21-2010, 09:38 PM
well - we are talking about two different clunks. i know your clunk also - and the fancy footwork is the fix for sure. the clunk i speak of is after you are already in gear and moving.

12-22-2010, 06:22 AM
You might try disengaging the clutch first, then letting up on the throttle a split second later. The RPM should rise about 100 rpm, then fall. This makes for a smooth shift by eliminating any brief engine braking effect.