2008 E93 M3 Manual Transmission problem

[skywalker562]

Before I start this thread, I want to mention following:
I followed precaution BMW lay out on M3 owners. “babying your machine up to certain miles and RPM and Speed restriction”
Second, I do not ride on my clutch or a hand on my shift. I shift gears when the clutch is fully pressed and then released. I hope I don’t have to explain how I shift my gears. I do as normal people would shift their gears.

Ok I guess everyone is on the same page. i have about 3000 miles on this car. Interestingly, I am not a real enthusiast like some of us in this forum. In my blood, I’d like to be but i still need to baby it for another couple of thousand miles. (just personal preference so please don’t throw rocks at me). I experienced some weird “clunk” sound and grinding from 1-2 shift. I searched threads that discuss about characteristics and problems of M3 6-manual transmission. more and more I read about it, I was certain that mine is not normal. Some people did get new transmission assembly because of this problem. I went to Crevier BMW Santa Ana, CA for service. Not just once but twice. First time, I talked to SA and he said he would look into it. Came back negative. The SA told me it’s normal and because of characteristics of M3 transmission, very tight tolerance level and machining, it should do that. He sounded convincing. I had to trust him since he knows more BMW cars than I do. I brought the car back and since then it bugged me but as the SA said, it’s normal and I have to deal with it. One day I went out for lunch with my coworkers. They are all mechanical engineers (I am a chemical engineer) and know cars ins and outs. One of my principle engineers told me my transmission is not normal. I chuckled and told him about my previous experience at the dealer. I went back to the dealer and ask them to do another test. When I got a call from the dealer, I went there with my principle engineer. Below is part of my principle engineer’s email:

“
Your issue is the second gear blocker ring and synchro assembly. This basic design has been around since Warner Gear installed them in mid-1930's transmissions. The brass blocker seems to be dropping out too soon, allowing enough rotational speed between the gear's dog clutch teeth and the sliders' grooves, to hit the slider's mating grooves too hard. The slider usually has a trio of spring loaded push bars called synchro keys. As you shift, the moving slider pushes these keys against the blocker ring on to the cone. The blocker ring cuts the oil on the gear's cone, and friction develops, making the blocker and gear match rotational RPM. Once speed is matched, the force on the slider keys is reduced, freeing the slider to move forward, and the dog clutch engages completing the shift.

Your 1-2 slider springs are too weak, or the blocker ring is machined wrong, so the blocker is dropping out of action either too soon, or not matching RPM with the applied force available from the slider keys, allowing the dog clutch to hit tooth-to-slot.

This is the clunk you hear. If you shift faster (per the dealer "expert"), the blocker ring is more highly loaded against the keys, perhaps getting a full RPM match before the dog clutch engages, and maybe you get a clean shift. This will wear out the slider fork surfaces faster, making a sloppy noisy tranny quickly.

But why do you have to beat up the transmission to get a clean 1-2 shift?
“

So he and I went back to the same SA and he started discussion why he thinks that this transmission is not normal. The SA’s reaction? Ummmmm. “You probably need to take to BMW manufacturing or transmission manufacturer. He can’t do anything but saying it’s normal. I will try to record sound when it clunks. Let see if BMW representative gets back to us.

[H Bomb]

well i haven't driven in your car or heard it so i can only speak from personal experience and 3 6sp manual M cars now with my E92 as my most recent and a E46 M3 and E39 M5 before

in all 3 i have noticed the 1-2 shifts at low speeds always clunky and noisy etc, and most everyone will tell you it is normal for these cars. all 3 of my cars had it and i never had any tranny problems with any. my M5 had 80k miles on the orig tranny and my M3 had 60k miles on the orig tranny

hope that helps some. it may not be right as an engineers view but it appears BMW has no intention on changing it since it has been like that on all of my M cars

[McLuVan]

mine does the same thing

[M3Alpine]

same here.... im used to it,all my m's have done this

[mvagusta]

clunk mine does too. But the grind from 1st to 2nd is not right..If you shift to fast it will grind. You pretty much have to really delay your shift to second and clutch and hold. That is not what a car with this much caibar should be doing..I think there is a issue that bmw does not want to pay for.

[ilidon]

400 miles and has been clunking all the time. based on the discussions that i read about this issue, i think its normal and try not to be affected by it.

[Eugene-TAIWAN]

its the worse thing about this gear box is 1-2

getting a heavy shift knob and a RE SSK can help out with that problem

[H Bomb]

^

yup the RE SSK i put in shortens it up enough in the 1-2 doesn't have as much room to clunk clank like it does stock

[JCtx]

OP, have a few questions and thoughts:

- Did you just start having this issue or it's been there all along?
- Can you please explain better under what conditions are you getting the grind? Again, the clunk is normal, but a grind is not. Explain if shifting leisurely, quickly, at what rpm, etc, etc.
-Does it happen just when cold, or hot and cold? EVERY manual tranny I have and have had is notchy and difficult to shift smoothly when cold, especially the 1-2 shift.
- Did you know it takes at least 5K (usually 10K) to fully break in these trannies? I also have 3K on my car, and it's been shifting better and better.
- Are you sure it's not your shifting technique? And I mean this is a nice way, not implying you don't know how to drive. I've been driving manuals all my life, and am still getting used to shifting this car smoothly (it doesn't help that I drive other manual cars). It pays to play around with your shifting technique, especially with the 1-2 shift. If you're pulling the lever to the left even slightly, you can get a grind. Try shifting with 3 fingers (ring and index in front, thumb on back) so you don't put any undue pressure on the linkage, and report back to us.
- Did you get your tranny fluid replaced at the 1,200-mile service? Check your invoices.
- And finally, the best way to find out for sure if your car is normal or not, without getting frustrated , is to swap cars with another forum member willing to help. Or even better, just ask a member with a manual to just drive your car with you on the passenger side and tell you if it's normal.

Just trying to help you get the help you need. Remember these cars are inherently noisy and clunky to some degree. Take care.

[mikeyr0x]

Mine is clunky too, I'm getting used to it at about 7k miles. Frustrating at times yes. I just try and allocate more time for warmup when its cold and always improve and be mindful of my shifts.

OP report back to us

[Kyoshi71]

This is just "M" specific right? All my other BMW's (5) have been manual and I never noticed anything.

[scotsman]

mine grinds really bad on the 1st to 2nd shift if I'm driving hard and try to shift fast. I thought it was just me but now it's making me have second thoughts. I feel like my foot is almost to the floor with the clutch and it still does.

[saeedg48]

Mine has always had this problem, but it's not a problem.. it's normal. If anything get new transmission fluids..

[L3M3]

Hey all. Posting here because I literally JUST got back from the dealer after taking my '08 E93 M3 in for these symptoms. I guess I got the right tech with enough perfectionism, because he said there is indeed a synchro issue on gear 2, and also a related issue which causes the transmission to "shudder" and shake a bit when shifting into gear 3. These issues apparently go hand-in-hand and are covered under warranty. So if you try hard enough and describe the problem well enough, you might be able to get it covered.

What I told them:
* Shifter "crunches" (not grinds), when moving into gear 2 with clutch fully depressed. This can be reproduced while engine is off/parked, and while driving. Feels like syncro's are not helping to engage.
* Transmission and body "shudders" laterally along the length of the car, felt through shifter, when shifting at low speeds from gear 2 to gear 3.

Not set in stone yet, will post back with more results when they call me back, but the tech thinks that a full transmission replacement is likely.

I think it would take a bit of an obsession with perfection to notice this problem. But if you own an M3, you probably crave perfection

[mosx]

Best of luck. Don't let them tell you that they're going to replace the clutch. I took mine in for this issue and they decided the clutch needed to be replaced. 1000 miles later its still doing the same thing. I go back in on Monday, hopefully they'll replace the tranny this time.

[L3M3]

Update. They gave me a new tranny. Problem solved, though I do admit they are right. 2nd and 3rd gear frequently are a bit rough, but nowhere near as horrible as they were before. Now the entire gearbox feels like a precision machine.

[BPMSport]

1st to 2nd has always been annoying. But I've gotten used to it. I've taken mine to the dealer a few times. They always say that it's normal.

If you shift super fast it will grind too.

I'm happy with the transmission but agree that second gear isn't as good as it should be. I'm going to try changing the fluid in a few thousand miles and see if that rectifies the issue at all.