915 stuck in gear(s)

[Burzel55]

I have a 72 T with a 2.4 and a 915 transmission. The car is in both 1st gear as well as reverse. Has anyone alse encountered this problem and if so is there a remedy without dropping the motor/ tranny? any help would be greatly appreciated

[pwd72s]

My thought? Judging by your problem description? Pull, dissect, and then think of solutions... But..this is just my thought...unless perhaps a simple clutch cable adjustment problem, or something wrong with the shifting mechanicals? Start there first...

[Jol Dantzig]

I have seen this occur when a lockout "pin" is replaced from the wrong side when the transmission is rebuilt.

I'm not sure if this is an accurate or clear description as I am not a "tranny" guy myself. However I do know (from first hand experience)that you can drive the car fine until you use reverse.

You didn't mention the circumstances, so maybe this isn't how it happened for you, but it is possible.

Will the car back up?

Jol

[Hayden Burvill]

Burz,

A correctly assembled 915 can be in both 1st and reverse at the same time.

The interlocker mechanism - for the most part foolproof - operates on adjacent shift rails, as there is a sliding action in the transmission that can act on adjacent shift rails simultaneously.

So in 1st or 2nd, neither 3rd or 4th can be engaged. 5th and reverse can.

In 3rd or 4th, neither 1st, 2nd, 5th, or reverse can be engaged - as the 1st /2nd rail is adjacent to the left, the 5th / rev rail is adjacent to the right.

In 5th or reverse, neither 3rd or 4th can be engaged, but 1st or 2nd can.

To alleviate your problem without pulling the tarnsmission, you will have to drain the oil and pull of the bottom cover plate.
Then make a hook out of stout wire (like 3/16") and feed it forwards (in chassis line) to reach the 5th/rev shift fork and pull it out of engagement.

Make sure you dont pull it into 5th, or your problem will still exist. For 5th, you have to push the shift rail forwards through the large hole near the opening for the bottom cover.

It will help if you can familiarize yourself with the lay-out before you start.

Was this immediately after a rebuild, or did it happen in teh driveway or ?

Regards

Hayden

[Burzel55]

Thanks for the response. It happened trying to back it off a trailer. I ahd the trans. rebuilt last spring and have only driven the car a coipl etimes since. The first time was no problem. Is htis common? Shoul dI be doing something to prevent it from happening again?

[power]

I had the same problem on a 72 915 Transmission. I was able to remove cover plate (just like Hayden says) and diagnose the shift dongle had jumped the fork and the transmission was stuck in two gears. I just removed the fork and got the 5th gear selector out of gear and and reinstalled the fork and coverplate, and everything was O.K.

[Hayden Burvill]

Burz,

It is very uncommon, but as it is technically feasible...always possible it can happen.

If you are certain it was 1st and reverse, not another combination invloving the 3rd /4th shift rail, then it is probable your transmission is correctly assembled.

If you are pretty certain your transmission is correctly assembled - then follow this possible logic;

Did you have the trasnmission in reverse when you were backing off the trailer?

Was there a sudden jolt of any kind when the car was backing off the trailer.

The first time we learned that 1st and reverse could be selected together was when we shipped a fresh race transmission in a sturdy case. The case had been dropped on it's end - with enough force to jolt the 5/r shift rail into reverse.
The transmission had been shipped in 1st gear.
So now the customer had his brand new $10K+ race transmission sitting on the floor stuck in 2 gears - not a good start!!

Now we ship all transmissions in 3rd gear - eliminating this risk.

If you were rolling off your trailer and this might have caused it to happen - then consider rolling off in 3rd or 4th with the clutch pressed in - this will prevent any shift rails from moving.

If it happens again, I would consider it more than coincidence and be looking inside the transmission to see what is not right.

Regards

Hayden