Transmission trouble

[E46m3zcp]

Hello,

My car is an SMG. I am trying to figure out if my trans would need a rebuild or if it's most likely the clutch/tob/flywheel. Symptoms in the video.
Summary of symptoms:
- When the car stands still, with foot on brake, a loud ticking is heard.
- When moving, the noise goes away.

FWIW: before starting to behave like this, there was some slack in the driveline and some clunking (not just the regular diff clunk, it was more a thud when shifting gears more aggressively). It might not be related to the current problem..

My specific question would be: if I step on the brake, will the SMG shift into neutral or leave it into gear and keep the clutch disengaged? My reasoning is this: if it's shifting into neutral, then my neutral gear might be shot and the transmission needs a rebuild. If it's not, and it's disconnecting the engine from the driveline, then it's most likely a flywheel or throw out bearing problem and I can do it myself.

https://youtube.com/shorts/yxe6ZXjlyQg?si=qgcRvwl4jpks28XY

[sapote]

My specific question would be: if I step on the brake, will the SMG shift into neutral or leave it into gear and keep the clutch disengaged? My reasoning is this: if it's shifting into neutral, then my neutral gear might be shot and the transmission needs a rebuild.

Major problem: the neutral gear broke!

There is no such thing as neutral gear.
When stopped from moving with engaged gear, it down-shifted to 1st, then just disengaged the clutch for a time, then maybe it will shift to neutral if stopping a longer time.

Nothing is wrong with the tranny itself, but the noise could be from the old dual mass flywheel.
About the TOB: when you shifted to neutral (no neutral gear but whenever no real gear is engaged), does it have the same noise as in video? If not then it could be the TOB going bad and not the flywheel.

It could also be the pilot bearing noise but it's hard to troubleshoot with smg as you can't command to disengage clutch in neutral at will, compared to 6sp manual.

[E46m3zcp]

The noise is the same when the gear selection is neutral.

[sapote]

The noise is the same when the gear selection is neutral.

Then it's not the TOB.
So either DM flywheel or pilot bearing.

In neutral gear, rev up to see if the noise goes away. If not then it's pilot, as rev up should quiet down the DM flywheel.

[E46m3zcp]

It doesn't go away. So I conclude it's the pilot.

[sapote]

Then it's not the TOB.
So either DM flywheel or pilot bearing.

In neutral gear, rev up to see if the noise goes away. If not then it's pilot, as rev up should quiet down the DM flywheel.

My bad. In neutral the pilot doesn't spin with clutch engaged as it should be, so the noise can't be from the pilot.

So it seems it's quiet whenever the tranny is loaded down, so I think it's a case of really bad DM flywheel.

[E46m3zcp]

Sapote, thanks, You always provide great insight. Are you a pro technician or just a hobbyist?

[sapote]

My hobby.

[jpy1980]

Love this forum. Some of these hobbyists on this forum probably have more knowledge on the car than official bmw techs at dealerships. Haha

[E46m3zcp]

I’m removing the transmission.

I’m thinking of going with OE dual mass FW and self-adjusting clutch because I am afraid that if I do anything not planned by the SMG TCU programming and calibrations it might not work properly.

Any advice?

I’ve seen that VAC motorsport sells kits for the SMG. Any experience with these?

[OldRanger]

In my 2005, I just replaced the SAC, DMF, and associated parts (a 6 Speed manual). I chose to stick with all OEM, even for a car that is nearly fully time track with about 320hp at the wheel with little concern for NVH.

[eacmen]

I'm removing the transmission.

I'm thinking of going with OE dual mass FW and self-adjusting clutch because I am afraid that if I do anything not planned by the SMG TCU programming and calibrations it might not work properly.

Any advice?

I've seen that VAC motorsport sells kits for the SMG. Any experience with these?

IMO unless you have forced induction stick with stock OE clutch kit

[E46m3zcp]

Ok, I will stick with OE, as I thought.

Alright so today I got to the transmission (removed exhaust, driveshaft, and all the stuff under the hood - fan, fan shroud,....). I'm following the steps from ISTA+ (TIS?)

Now I'm blocked at removing the pin from the gear selection rod (in order to remove the gear selector rod and SMG actuator from the back of the trans). There's a C-clip you have to push forward: that's done. The next step is to "drive out retaining pin on selector rod linkage with special tool 23 0 240." I can't get that pin out though, I think I've pushed on it hard enough from the passenger side of the hole. Any advice?

Also, the documentation that I'm following advises removing the intake manifold. I understand that the work done under the hood is to tilt the engine and transmission to access the top screws on the bell housing. It "feels" like this should be achievable with the intake manifold on. What are the "gotchas"?



Thanks!

[Icecream]

I think I remember sticking a small screw driver into the hole on the rod (on the selector rod) and twisting one way or the other against the spring inside the transmission (I think to the left like going into reverse) and that releases the tension on the pin.

[sapote]

I think I remember sticking a small screw driver into the hole on the rod (on the selector rod) and twisting one way or the other against the spring inside the transmission (I think to the left like going into reverse) and that releases the tension on the pin.

This is a great idea to release the pin. Actually the spring is inside the actuator and not inside the tranny, so try to rotate the actuator shaft instead.