Tranny symptoms, can you help diagnose?

[Deneb aka Doc Fjord]

I had a transmission installed in Doc Fjord (aka Rescue Bimmer). Here are the symptoms: It shift smoothly, downshifts smoothly with no synchro problems. But when it is in 2nd gear and I let off the gas peddle, it pops out of gear. You can feel the whole shifter move forward when in 2nd gear and you let off the gas...except when going slowly in 2nd and gradually let up on the gas - then it doesn't pop out of gear. Thanks for any ideas you might have.

[tech71]

13 minutes ago, Deneb aka Doc Fjord said:

had a transmission installed in Doc Fjord

OK, a little sparse on pertinent info sir.

What trans? 4 speed? 5 speed?  Shift linkage work performed or modified/ shortened for a 5 speed? 

Many times problems like this are a result of the shift linkage binding/ not allowing full travel..

[Dudeland]

30 minutes ago, Deneb aka Doc Fjord said:

I had a transmission installed in Doc Fjord (aka Rescue Bimmer). Here are the symptoms: It shift smoothly, downshifts smoothly with no synchro problems. But when it is in 2nd gear and I let off the gas peddle, it pops out of gear. You can feel the whole shifter move forward when in 2nd gear and you let off the gas...except when going slowly in 2nd and gradually let up on the gas - then it doesn't pop out of gear. Thanks for any ideas you might have.

Popping out of gear usually means bad syncros.  But yes as @tech71 stated,  more details please. 

Check your motor mounts and transmission mount. 

 

[Deneb aka Doc Fjord]

Thanks for the suggestions of what else I need to provide: Getrag 242, 4 speed. No shift linkage modifications, but the shift tower was repaired prior to the transmission install.

[Dudeland]

27 minutes ago, Deneb aka Doc Fjord said:

Thanks for the suggestions of what else I need to provide: Getrag 242, 4 speed. No shift linkage modifications, but the shift tower was repaired prior to the transmission install.

 Perhaps it was assembled incorrectly. 

 

[OldRoller]

2 hours ago, Dudeland said:

Popping out of gear usually means bad syncros

Likely worn synchros, but the reason for rejecting the gear on decel is worn engagement dogs on the 2nd gear. Throttle off, rotation reverses, worn dogs allow the shift collar to back off taking the shifter with it.

Fix is to replace the second gear and synchro ring as a new pair.

[TobyB]

If the shifter moves when you're changing from accel to decel in all gears,

then the main shaft is probably walking in its bearings.

 

If it only happens in 2nd, then it's possible the shift collar and/or 2nd gear engagement teeth

(OR's 'dogs' but pointier and more shapely) are significantly damaged.

 

There's a low chance it's just the synchronizer ring.

 

This is all kinda moot, though, as unless you can find an external cause (shifter hitting the tunnel, for example)

taking one of these things apart to fix it is quite a project, and parts are not trivial to find.

Getrag was a victim of their own success- these transmissions lasted so well for so long that no- one 

made parts for them nor learned how to fix them, and now, 50 years on, there's not much out there.

Any Mitsubishi transmission, now, parts for THAT are all over the place.  Including the road...

 

t

had a Gen 1 Montero more than twice...

[Mike Self]

3 hours ago, OldRoller said:

Fix is to replace the second gear and synchro ring as a new pair.

More likely, fix is to find a good tranny...surely there must be a few out there!

 

 

[Preyupy]

I think Toby is correct.  If you put your hand on the shifter and it tries to move as you get on and off the throttle, the gears are moving inside the transmission.  There is the possibility someone has been inside this gearbox and assembled it incorrectly.  If it is only 2nd gear I suspect they may have forgotten a spacer and there is excessive end float on the 2nd gear on the main shaft.  If it does it in all gears but 4th ( maybe not popping out of gear but shifter still moving) I would suspect the shims at one or both ends of the main shaft got left on the work bench.  This is not that uncommon when someone removes the front and rear seal housings to replace the seals, they don’t realize there are shims that keep the main shaft from moving.   

[Mikesmalaga72]

Perhaps another variable would be the shift detent spring/ball may have played out. Wonky or maladjusted shift linkages and/or shift platform as well as the others have described here. 

[jgerock]

Just curious- does the car have a soft (original style) shift boot, a leather style (witches hat) or reproduction (harder than factory) shift boot?  The reproduction ones tend to want to move the lever back to center.

[Deneb aka Doc Fjord]

Good question Jim. It has the original rubber gusseted boot

[OldRoller]

Deneb, given the cost of having your 4 mixer repaired (if you can find someone capable) Mike Self's suggestion would be a more likely avenue to pursue. Find a 4 speed someone has changed out for a 5... You may get a good one.

In the meantime, just hold the shifter back in 2nd, and enjoy the drive!

[jgerock]

12 hours ago, OldRoller said:

Deneb, given the cost of having your 4 mixer repaired (if you can find someone capable) Mike Self's suggestion would be a more likely avenue to pursue. Find a 4 speed someone has changed out for a 5... You may get a good one.

In the meantime, just hold the shifter back in 2nd, and enjoy the drive!

Hmm.   😉

[kbmb02]

sort-of off topic...

 

Way-back - during the times I went to the local circle-track stock car races with my Dad - I recall seeing a dangle of heavy wire on the dash of the car/driver we knew. The function of that wire/cable? To hold the shift lever in gear once the race started (it was a one gear circuit). -KB