Transmission trouble

[E46m3zcp]

George Hill yeah, that's an other idea I might do if an additional hour of struggle doesn't get that pin out. I'm worried about the need to bleed the hydraulic system and having trouble, I never bled this thing and INPA is unreliable... dreaded windows chimes and error messages in german about communication failing in the middle of a procedure got me cursing in the past lol.. something tells me we can all relate

[eacmen]

George Hill yeah, that's an other idea I might do if an additional hour of struggle doesn't get that pin out. I'm worried about the need to bleed the hydraulic system and having trouble, I never bled this thing and INPA is unreliable... dreaded windows chimes and error messages in german about communication failing in the middle of a procedure got me cursing in the past lol.. something tells me we can all relate

you're going to need a working INPA either way. After replacing the trans you will need to relearn the new clutch bite point etc.

[E46m3zcp]

you're going to need a working INPA either way. After replacing the trans you will need to relearn the new clutch bite point etc.

Yeah I'll figure it out. The point is I have a bad experience with INPA procedures that take some time to execute.

[E46m3zcp]

I was never able to remove the pin. I ended up disconnecting the SMG lines and removing the transmission with the actuator still attached...

I need advice on this: what springs would be a good idea to change "while in there"?

[sapote]

These need to be checked / replaced: 17 (only 3 sets of springs and sleeve in the odd number holes, don't touch the even holes), 8 and 9, 14, 15.

SMG don't have parts 1,2,3,4,5,6.

[E46m3zcp]

I think the noise in the video was due to the fork hitting the pressure plate, because the nylon fork pin broke and let the fork move. Here are my findings.

Wear marks on the fork:


About 2 inches distance between wear on the pressure plate corresponds to the distance between marks on the fork.


The pin was found broken.

[E46m3zcp]

What are fellow SMG owners doing for the slave cylinder? Bite the bullet and get a new Genuine BMW slave for around $400?

[oceansize]

What are fellow SMG owners doing for the slave cylinder? Bite the bullet and get a new Genuine BMW slave for around $400?

Yes. Its a once every 10-15 year or 100k mile part.

[sapote]

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

with the knowledge today, I can say that the above statement is not quite correct that the noise was there when tranny in neutral. When in true neutral, the clutch should be totally engaged (no pressure in the slave cylinder) and so the fork should not touch the PP to have the noise. However, It would cause the noise with car stopped but in gear with clutch disengaged (fork moved and touched PP) and I think this was the case, not in neutral.

The plastic pin broke. Is this the root cause leading to the noise? I don't think so.
The pic shows the PP/clutch disk were worn too far -- the self adjust 3 spring/arm expanded to their max position. This caused the slave to push the fork further to in order to disengage the clutch, far enough that it started touching the PP outside the fingers/TOB, which generated the torque to rotate the fork. When the fork wanted to rotate, it must break the plastic pin or jump off the pin.

As soon as the first sign of the rubbing noise appear during clutch disengaging, and if stop driving the car further, the pin wouldn't be sheared off.

I see 2 reasons for the pin to be broken this way: the TBO is seizing and allowing the PP to rotate the fork, or in this case of a worn too far clutch/PP

[sapote]

I was never able to remove the pin. I ended up disconnecting the SMG lines and removing the transmission with the actuator still attached...

You didn't try to remove the pin with the tranny outside the car? I would remove it and clean/lube the pin for easier to remove in future when tranny is on the car. You don't want to remove the tranny again for this small task.

[E46m3zcp]

with the knowledge today, I can say that the above statement is not quite correct that the noise was there when tranny in neutral.

It’s been quite some time but I responded what I remembered back then. I was pretty sure I had heard the noise even in neutral but I could be wrong. Now I don’t remember enough how I tested it to say.

The plastic pin broke. Is this the root cause leading to the noise? I don't think so.
The pic shows the PP/clutch disk were worn too far -- the self adjust 3 spring/arm expanded to their max position.

Really interesting. I will compare when I receive the new PP as I wouldn’t have been able to tell the adjustment mechanism is at its max.

[E46m3zcp]

You didn't try to remove the pin with the tranny outside the car? I would remove it and clean/lube the pin for easier to remove in future when tranny is on the car. You don't want to remove the tranny again for this small task.

Good idea. I have not tried yet.

[E46m3zcp]

sapote I'm doing some research to see if I can find out if it's possible that the clutch would be disengaged (open, slave cyl. pressurized), when the car is in neutral. While I agree that logic and common sense suggest that it would not, this information from the technical manual is still not clear to me but seems to mean that it could.

First screen shot for the definition of "Idle-speed" as the neutral position:



Second screen shot describes a "safety feature" in which it seems it is described that the clutch would disengage in "Idle-speed" position. My interpretation is that in certain conditions, if the engine speed falls below a threshold they disengage the clutch even if in neutral to remove a maximum of load and prevent stalling. It is unlikely that I got in these conditions but it is possible.


REFERENCE: SMG_technical_manual.pdf

[sapote]

sapote if it's possible that the clutch would be disengaged (open, slave cyl. pressurized), when the car is in neutral. While I agree that logic and common sense suggest that it would not, this information from the technical manual is still not clear to me but seems to mean that it could.

I think the text "idle-speed position" in the text below is wrong, and it should be “forward-sequencial mode position" instead.
I believe the idle-speed(0) (Neutral) is the postion of the shifter in between the R gate and the Forward-sequencial position as I try to draw below:

R.............. -
|___N____|
................. |
.................+

when shifter at N position, the gear is in neutral with clutch engaged (except during engine starting).
When shifter at the forward-sequencial mode postion (between + and - plane), the tranny is in gear most of the time except when stopping at idle for long enough then it will be shifted to 0 neutral with clutch engaged.
so the "Safety Functions" feature only happens during when the shifter is in the forward-sequencial mode at low idle speed, and not when it's at the N position.

[E46m3zcp]

Well the bread trick isn’t working for me. Pilot bearing’s blue “cap” broke and the bread is coming out through the bearing. I tried for about 1h and it won’t budge. What do people use for this?





Thinking of using J-B weld to glue a washer to the front, blocking the bread from coming out. Is this a bad idea? (taking care not to glue the sides of the bearing in)