niclase

Hi!

We have a problem with a 5R where the gearbox sometimes engages two gears at once.

First time it happened we took the box down and slid the engaged rod back. We thoroughly tried to re-create the problem but failing to do so we went over all the detents, did a visual inspection and everything looked good so we figured it was some freak coincidence that caused it and put everything back together again.

Today it happened once again while loading the car. Second gear (I think) is engaged but the gear selector is not in the slot on that rod so no way to disengage it. Will have to take the box down once again

The big question is - how can this happen? The box has been apart so obviously something has been missed. But what? Everything seems fine with the box on the bench..


Any tips and thoughts on how to prevent the same thing happening again would be much appreciated!

Thanks!
//Niclas

Oddjob

Sure seems like the problem is with the rod lockout detents.

niclase

Sure seems that way.

With the gearbox down it turns out that it's possible to engage second gear if the box is already in reverse and first gear if the box is already in fifth. Any idea exactly which detent should keep this from happening?

Guessing it isn't possible to fix without teardown?

Dave W.

The reverse lockout detent is located on top of the trans, next to the shift rod end cover. Check that first. The other detents for 3/4 and 1/2 shift rails can only be reached with a teardown.
I can take pics if you need it, I'm currently refreshing my spare trans and it's completely disassembled right now.

Dimi 944

The issue is more than likely due to a missing lockout detent which is housed in the 3rd/4th gear shift rod. It is a small dowel/pin (~3mm x 8mm) which seats in a cross drilled bore in the the 3rd/4th gear shift rod. When in 1st/2nd or 5th/reverse gears the small dowel/pin pushes up or down the bigger dowels that lock in place the the rest of the shift rods. With this small dowel missing the bigger dowels are free to move in such a way that when 1 or 2 gears are engaged the shift rod for 5th or reverse is not locked out and it can be moved as well. Same is valid the other way around.

951and944S

This...^

You can remove the two 10mm bolt cover and remove the spring plunger and realign the shift forks with a creative tool without lowering the transmission.

Only way to permanently repair is remove and disassemble to install missing pin.

T

Dimi 944

Attached is a picture of the three dowels and how they are aligned. The one that is more than likely missing is the small dowel in the middle.

Dave W.

Here's the parts Dimi is talking about. The pic shows the 3/4 shift rod, the small detent fits inside the 3/4 rod.

Dimi 944

Getting the shift rods aligned is possible without dropping the transmission. Re-inspection the small dowel requires the transmission to be off the car and some small tweezers for inserting the dowel in place.

I have a few dowels available too.

niclase

Big thanks for all the help!

Looked at that drawing a few times but failed to realize there was a pin through the center and couldn't figure out how the lockout was supposed to work. Seems pretty obvious in hindsight :/

Transmission is already taken down, advantage of this problem is I'm getting pretty quick at doing that

Not sure I follow, is it actually possible to somehow insert the pin without tearing apart the box? That would be fantastic, but I dare not hope for it

951and944S

Uhm, yes....?



This is what I posted.

T

951and944S

I have found a couple of these on diff cover magnet, obviously displaced during assembly and not noticed by person working on it.

I use an automatic transmission assembly gel call 'Transgel' used in autos for holding valve body check ***** in place.

I guess any grease would work.

To be clear, yes, you can realign shift rails into neutral without removing trans but you must remove, disassemble and drive out fork pins to be able to slide shift rod enough to re-installed missing pin.

T

Dave W.

Here's a quick outline for reinstalling the missing dowel.
Remove the trans, remove shift selector cover and selector rod, remove the steel gearset case from diff housing. I don't think you need to remove the diff, end cover or any part of 5th gear assembly. Make sure 5/R and 1/2 rails are in neutral. Press out the roll pin for 3/4 shift fork and slide the 3/4 rail out. Check your work and reassemble.

niclase

Thanks! I had already taken the box of the car when writing the first question, so for a short while there i got the impression it would be possible to install the missing dowel without opening the transmission, of course to good to be true

Had it fixed tonight by a friend and the car is now put together again. Let's hope there will be no more then one gear engaged at a time in the future. Don't feel like practicing my gearbox removal skills anytime soon

Thank you again for all the help, much appreciated!

Dimi 944

Glad you fixed it.