Potential new tranny?

[UntzUntzUntz]

Hello everyone. This is actually my first thread here. Been around Bimmerforums for a little and found the community is far greater at zpost so maybe you guys can give me a hand here.

I just got an 06 m roadster few months ago. Ever since I got it, I've been hearing rattling noises going from 1-2 gear. From clutch going in, shifting to 2nd and letting the clutch out. After that, it's butter. It's always an unpleasant noise and kick that makes the passenger, well.... Sometimes it goes away but initially it's always there if not done at a certain rpm and exact moment that needs to be shifted. Don't even get me started on cold starts. I worry the person taking a stroll down the block would start laughing from the loud transmission rattle it makes between those gears

So I decide to take the car over to my uncle, who works on transmissions for as long as I can remember. Test drove it, nothing wrong, kept it overnight to check it out on cold starts, nothing wrong. I went by about a month until it just drove me nuts. So now I turn to you fellow z owners. Are rattling noises normal when clutch goes in from 1st and clutch goes out into 2nd? Does your z shift smooth from 1st to 2nd? (without putting as much effort as I mentioned above)

I understand "rattling" noises is very generic and could be a list of problems. I just want what you've experienced that could give me some sort of direction I can go to with this.

Thanks!

[StickMon]

Doesn't sound right.
I have the same car and no trans noise. Shifts smooth through all gears.

Maybe the clutch isn't fully disengaging?
Does it have an aftermarket adjustable clutch stop?
I would try bleeding the clutch.

[UntzUntzUntz]

Originally Posted by StickMon

Doesn't sound right.
I have the same car and no trans noise. Shifts smooth through all gears.

Maybe the clutch isn't fully disengaging?
Does it have an aftermarket adjustable clutch stop?
I would try bleeding the clutch.

I doubt this car has any aftermarket parts. It just comes as a shock since the car only has 38k miles on it. But then again it could've been mistreated the whole way through. Or someone just drained all my trans fluid...

A few details I left out from my original post I just remembered. The clutch makes a rattling noise when it goes in. Mainly in reverse, 1st gear, and 2nd gear. Another thing I've noticed is the shifting gets much more difficult when taking a slow sharp turn. It's almost like the gears get locked in, if that makes any sense. Not sure if they have anything in relation though.

I think I'll take you on bleeding the clutch. It'll be my excuse to do a CDV delete

[tikamak]

Originally Posted by UntzUntzUntz

I doubt this car has any aftermarket parts. It just comes as a shock since the car only has 38k miles on it. But then again it could've been mistreated the whole way through. Or someone just drained all my trans fluid...

A few details I left out from my original post I just remembered. The clutch makes a rattling noise when it goes in. Mainly in reverse, 1st gear, and 2nd gear. Another thing I've noticed is the shifting gets much more difficult when taking a slow sharp turn. It's almost like the gears get locked in, if that makes any sense. Not sure if they have anything in relation though.

I think I'll take you on bleeding the clutch. It'll be my excuse to do a CDV delete

Perform a CDV delete, drain out the transmission fluid out and put a 50/50 mix of MTF LT2 and automatic transmission fluid.
Get vorshlag engine and transmission mounts Or vibratechnics.

After all is done, always shift 2nd while pulling to the left and with a slight pause that is synchronized with your leg.

Learn this and you will feel the tremendous grace this power has.

Basically the 2-3-4-5-6 gears are butter smooth all the time and the ZF transmission is very very (i repeat VERY) strong transmission. i've seen the internals, you can't break this transmission even if you try and it's very lightweight in comparison with a 6 speed getrag from the M3.

only thing is the damn triple synchros in 2nd gear.

[elerner61]

Here's another thought (based on the rattling you mention when using the clutch), perhaps something has gone awry with your flywheel. The M's have a dual mass flywheel. It is known to make a rattling sound when you turn off the engine which is normal (if you hold the clutch in when turning the engine off it doesn't make the annoying rattling sound.)

If this rattling sound is happening while the car isn't moving and you are actuating the clutch it may not be the transmission, and be caused by the flywheel.

[The HACK]

Replace the transmission mount. It's busted.

[Finnegan]

Originally Posted by The HACK

Replace the transmission mount. It's busted.

Quite likely.

I'd check the motor mount bolts too while you're at it.

From there if nothing is found go on down the list.

[UntzUntzUntz]

Yeah that'll make the picture more clear. I'll take a look at it tomorrow. I get the feeling it's also the mounts. Passengers always complain that not only do they feel every crack on the road, but the kick it makes from 1-2 on top of that just looks like a bobblehead sitting next to me.

From those gears it's always, 1st gear, one heartbeat, 2nd gear. It'll be a disaster if I dare try to shift faster or slower than that. I've heard that's normal however? This transmission doesn't like to be shifted quickly? Sounds kinda ridiculous. Thoughts?

[StickMon]

I've always shifted in two motions.
No significant hesitation in between, but one pull to get to neutral, relax, another pull into gear.

As soon as I read "much more difficult when taking a slow sharp turn" I thought "Yep ... mounts".

[tikamak]

Originally Posted by UntzUntzUntz

Yeah that'll make the picture more clear. I'll take a look at it tomorrow. I get the feeling it's also the mounts. Passengers always complain that not only do they feel every crack on the road, but the kick it makes from 1-2 on top of that just looks like a bobblehead sitting next to me.

From those gears it's always, 1st gear, one heartbeat, 2nd gear. It'll be a disaster if I dare try to shift faster or slower than that. I've heard that's normal however? This transmission doesn't like to be shifted quickly? Sounds kinda ridiculous. Thoughts?

It's the contrary, this transmission can be shifted lightning fast.
It's just that 1-2 shifts needs to be very very accurately timed.

try shifting 3-4-5, you can make the tyres spin at 60+mph

[UntzUntzUntz]

So most likely it's the mounts. We shall find out tomorrow.

I guess my sources are wrong about the trans... but tires spinning @ 60+??? Mine only spins when I engage into 2nd lol I wanna have w.e that guy's having!

And YES. It needs to be super accurate between those gears. Such a bad girl she is

[tikamak]

Originally Posted by UntzUntzUntz

So most likely it's the mounts. We shall find out tomorrow.

I guess my sources are wrong about the trans... but tires spinning @ 60+??? Mine only spins when I engage into 2nd lol I wanna have w.e that guy's having!

And YES. It needs to be super accurate between those gears. Such a bad girl she is

Easy, at 2nd gear 8000 RPM, shift into 3rd like the SMG shifts.
You need be CDV less.

PS:
my car is supercharged but my point is that you can shift as fast as your hand and feet can shift and the transmission likes it.

[UntzUntzUntz]

Originally Posted by tikamak

Easy, at 2nd gear 8000 RPM, shift into 3rd like the SMG shifts.
You need be CDV less.

PS:
my car is supercharged but my point is that you can shift as fast as your hand and feet can shift and the transmission likes it.

I think it's because of the thick ass tires in the back lol. but then again... I've never fully redlined the car... time to take away her virginity

Thanks akha jan

[UntzUntzUntz]

So here's something I didn't expect. The car has no issues. Mounts are fine. And apparently it's normal for it to rattle. The dual mass flywheel creates a rattling noise at random occasions when the clutch disengages at a certain rpm. It's never predictable exactly when it will rattle. So, Elerner61, you were correct.

Thank you everyone for sharing your .02. An extra z4 will continue to stay on the road

[elerner61]

If it was diagnosed to be your dual mass flywheel then at least you know what is causing the noise. That said, it is not normal for the flywheel to make noise under the situations you describe. Live with it if you like, but most if not all of us are only hearing that noise when we turn off our engine with the clutch out (happens every time)

[UntzUntzUntz]

Yeah that much is normal I understand. I always turn off while the gear's in anyway. However, it sounds logical to me that it rattles when it gets disengaged from the clutch. Sure it's embarrassing when I have passengers but who cares, they can leave, less weight in the car

I'll definitely be keeping an eye out if it gets worse and maybe when I get a chance to drive another M I can see the real difference. For now, case closed lol

[XMetal]

Originally Posted by UntzUntzUntz

Yeah that much is normal I understand. I always turn off while the gear's in anyway. However, it sounds logical to me that it rattles when it gets disengaged from the clutch. Sure it's embarrassing when I have passengers but who cares, they can leave, less weight in the car

I'll definitely be keeping an eye out if it gets worse and maybe when I get a chance to drive another M I can see the real difference. For now, case closed lol

The clutch disengaging rattle in 1st and reverse is normal (so I've been told). I have it and heard it on M3s as well. I had/have it before and after engine/transmission mounts upgrade (all engine mount bolts were updated with 10.9 Motorsport bolts as well). This happens only when driving in low RPMs, usually in parking lots. It's fine otherwise during normal launch and shifts.

Where are you in So Cal? You're more than welcome to take a spin in my coupe to hear and compare noises.

[UntzUntzUntz]

Originally Posted by XMetal

The clutch disengaging rattle in 1st and reverse is normal (so I've been told). I have it and heard it on M3s as well. I had/have it before and after engine/transmission mounts upgrade (all engine mount bolts were updated with 10.9 Motorsport bolts as well). This happens only when driving in low RPMs, usually in parking lots. It's fine otherwise during normal launch and shifts.

Where are you in So Cal? You're more than welcome to take a spin in my coupe to hear and compare noises.

I'm more closer to the valley. Live in Granada Hills, work in Canoga Park, and school in North Hollywood. I'm all over the place lol

If you're around those areas I would love to. You can take mine's for a spin as well. Maybe it's just the way I drive

[XMetal]

The valley is a bit of a drive for me. If you're ever in Orange County (Irvine), feel free to drop by

[UntzUntzUntz]

Maybe on the way down to BigSoCal Euro meet woowoo!