"Fake Neutral", Lockup on M90. Bent Selector Plates?

[940driftsled]

Hey guys!

I'm having some issues with my M90 transmission (of course). I just swapped from a M47 to this M90 on my B230F 940, but apparently this M90 is possessed. The car has dog-dish flywheel, custom homemade transmission crossmember/mount, and a fresh clutch setup.

Now onto my symptoms:

Sometimes I’ll check that the shifter stick is visually and physically sitting dead center in the Neutral position, but when I let the clutch up it starts grinding and after adjusting the shifter a bit the grinding stops. Otherwise I don't have any grinding when selecting any gears. This has happened previously and when I try to push the car with the engine off its like it would be stuck in a gear even though I can clearly see that it is in neutral.

When I start reversing I obviously select reverse gear and let the clutch up, the car moves back a bit clunkily and when I push the clutch back in the car suddenly stops like I would've slammed the brakes. When I tried to select 1st gear after this I physically got blocked when trying to get the gear in, I let the clutch out and then in again and then suddenly I'm able to select 1st. With the car off I can select every gear with no issues, and it is clear that it has selected a gear. There is no slop in the shifter linkage under the car either.

Has anyone had these symptoms before and should I throw this transmission in the bin and buy a new M90 or even a ZF?

 

[petiww]

I can imagine that something was overloaded in the selector mechanism. Maybe during handling the transmission, or during removal/installation.
I'd try to identify which gears are affected before disassembly.
Is the shifter travel the same in all 6 gears? Is the shifter feel the same?
Can you introduce the grinding in neutral when trying to slightly preselect any gear?

http://forum.vccn.no/img-dump/2011/08/1910.jpg

 

[940driftsled]

Yeah id say something was overloaded in my first test drive, since I could actually drive it then, now nothing works. Id say that shifter travel is more or less the same in every gear. I have sometimes been able to get grinding even in neutral, like its on the edge of selecting a gear even though I can do the neutral wiggle. I will try to open up the transmission before buying a new one, hopefully it might be a simple fix!

Here are some videos of my symptoms:
When trying to drive
Shifting
Grinding at neutral

 

[okoye]

Did you bleed the clutch properly. Did you put the bracket that holds the shifter up on the transmission tunnel? Something could be broken on the internal shift mechanism, I had that issue and had to rebuild mine.

 

[940driftsled]

Clutch is bled properly, no air in the system. The shifter is also properly installed, I also personally believe that something internal is broken. I think it could be a fun project trying to rebuild this transmission so I think thats the next step! What had gone on your transmission and was it difficult to repair?

Did you bleed the clutch properly. Did you put the bracket that holds the shifter up on the transmission tunnel? Something could be broken on the internal shift mechanism, I had that issue and had to rebuild mine.

 

[okoye]

Clutch is bled properly, no air in the system. The shifter is also properly installed, I also personally believe that something internal is broken. I think it could be a fun project trying to rebuild this transmission so I think thats the next step! What had gone on your transmission and was it difficult to repair?

The repair isn’t hard there’s a video on youtube that shows how to disassemble the gearbox. It’s really easy. It took me a few tries because I had to replace the shift plate and that Also ended up being bad. Replace the selector tips and check the shift plate. There should be no resistance once assembled