915 Stuck in Reverse

[AMSRoadRunner]

Just finished my first 915 rebuild! YEA!! Took me almost 3 years to build up the courage (and funds).
Now I have the motor and trans back in the car and it acts like I am always in reverse. Feel like I can grab a gear (third maybe?) but it will stall when I try to let up the clutch.

Any thoughts? Suggestions?

Thanks!!

Andrew

[Jon B]

Andrew,

Assuming your linkage couplings aren't loose(?), do you have any neutral situation where the engine will idle with the clutch engaged (foot off the pedal)? If you're stuck in reverse, you shouldn't be able to shift into 3rd or 4th, unless you let the midcase interlock plunger slip out of position. Tell us what happens when you shift the lever into every position- 1st, 2nd, 3rd, 4th, 5th, reverse, and let the clutch out. Will the lever go into every position?

[Jon B]

Another possibility- the 5th/reverse operating sleeve wasn't adjusted or fastened properly, and in a neutral rod position is engaging the idler. Tell us what happens when you shift the lever into every position.

[john walker's workshop]

remove the back up light switch on the end of the trans and force the pin inward. some go easy, some take some effort.

[lindy 911]

I had the same issue and John had the same advice and it worked. Pull the reverse light switch at the front of the trans and push the rod back in. The cause for mine and the likely cause of your trouble is a shifter that's not aligned properly with the shift in-put shaft on the trans. Mine is now aligned and shifts like new.

Lindy

[AMSRoadRunner]

I am really liking the reverse light idea.

The other bit of information (and what I am really afraid of) I did not adjust the 5th - reverse stuff, because it looked good, I didn't change anything and I was running out of time. (always a good thing to rush these sorts of things, right?)

For those of you trying to tell me to shift, I haven't got the shifter hooked up as you need to grab first, first and as of yet, I have not been able to do that. (I think my English teacher is going to kill me)

Now, on the detent, that triggers the reverse lights I really should jack up the car from the front so all of my expensive oil drains to the back, correct? Also I think with some amount of playing with the input shaft I can get the trans into neutral, which I should also do first, correct?

[lindy 911]

The input shaft would not move on mine until I pushed the rod back in. Then I found neutral, then I properly aligned the shifter coupler. There are some pretty good threads here on how to do the alignment.

Lindy

[AMSRoadRunner]

A little tough to push in?!?!
I am going to try to drop the transmission so I can get a drift and hammer on the pin!!

[Christien]

I had the same problem, pulled the reverse light plug and pushed the pin to get it out of reverse. Yes, jack the front of the car up to save most of the tranny oil - some will still come out, depending on how high you jack the front.

Mine was ridiculously difficult to push in. I ended up fabricating a tool out of a large allen key, so that I could hammer it. You DON'T have to remove the tranny - just figure out a way to get force on it. It's possible. Once I had the tool bent into the right shape, a couple hits with a hammer got the pin pushed, no problem.

[Jon B]

Andrew,

In your initial post, you implied you can select 3rd with the trans stuck in reverse, and the engine stalls. You SHOULDN'T be able to select 3rd or 4th with the trans stuck in reverse, it means your interlock plunger has slipped out of position, and may be why you're having a problem. If so, you'll run the risk of selecting two gears at once someday.

[AMSRoadRunner]

News!
I removed the reverse detent light switch rod thing and now have all 5 gears!
The smaller diameter end goes into the case first, correct?

[john walker's workshop]

no, toward the switch. did you pay attention to the two internal detents when you assembled the trans? the one in the diff housing goes between the shift rods and the one in the end of the center housing goes all the way down under the shift rod. failure to assemble them in the proper position will result in this happening again further on down the road.

[lindy 911]

Thank you John Walker!

[Jon B]

If it happens again (and again), you'll know what to do.

[AMSRoadRunner]

Hmmmm. I got it installed backwards... Won't work if I install the other way around... Think that is going to bite later? Since it seems to be working, I am tempted to leave it.

I am pretty sure I got all of the internal detents in the correct spots. But then again my best friend John and I put it together...

Now I am fighting a no spark situation. If we all turn to page 280-9 in our Bently manual we see that we are told to check coil values on table b. So we find table b two pages later only to discover table b is for the reference and speed sensors!!

Don't think the ol blue 911 is coming on vacation this time around!!

Thank you all for all of your help!! I am going to give the connectors for the reference and speed sensors a good wiggle then resort to taking the old volvo war wagon.

Andrew

[john walker's workshop]

if the pin is backwards, it binds in the switch and the reverse lights stay on, sometimes.

[cdadaa]

Sorry to hijack this thread but it seems appropriate in light to the "stuck in reverse" discussions.

I too just finished installing new syncros and seals. The tranny too is stuck in reverse, but the reserse switch pin appears to be okay (already pushed in). It's not out and exposed and I can't feel it in the socket.

The tranny is stuck in reverse when the shifter is in the neutral position. When I go through the gears, the tranny is locked. The only time I can get the wheels to move is in N.

On the initial test drive, it had 3rd 4th & R. After adjusting the shifter, it appeared that I got 1st, then I fiddled with the adjustment a little more and that's when everything stopped.

It's on jack stands and it is still locked.

Any suggestions?

Thanks...Dan

[john walker's workshop]

the reverse light switch pin is pushed into the switch by a roll-pin sticking out of the reverse/5th shift fork rod. if the roll-pin is gone, there's no way to cheat it out of reverse without removing the end cover. the rod is not available through the plate on the bottom of the center housing like the 1-2 and 3-4 rods.

[Jon B]

Dan,

A properly built and adjusted 915 will not find itself stuck in reverse, EVER. And if it happens once, it can happen again, and again. I tried to have Andrew determine what his problem was, but the quick fix was more appealing. It's like having a car with bent suspension, causing a badly worn tire, and the quick fix is a new tire!

If you're interested in determining why this is happening, please first tell us a couple of things: with the transmission currently stuck in reverse, can you shift into 3rd or 4th gear at all? If so, does it then lock up? Also, the large removable cover plate on the midcase has a guide fork attached to it- did you make sure the nuts holding the fork were secure, not loose?

[cdadaa]

John and Werkstatt,

Thanks for responding so quickly!!

I appears that I can go through all gears (with the shifter and on jack stands) including 3rd and 4th. The tranny is locked up in all gears but N, which is in reverse. I just checked the reverse pin and was able to stuck several inches of a welding rod into the guide hole. It doesn't appear that there is even a pin there?? I did not remove the switch during the rebuild and honestly don't remember the pin during the rebuild (several months ago before the engine rebuild). I'm going to check my pictures as I took hundreds of them.

I'm not sure what removable cover (inspection plate?) you refer to, but I was very careful in checking and rechecking all of the nuts and torqueing as required,but that's not to say I missed something...I just don't think I did.

The roll-pin you refer to requires that I remove the nose cone correct (which means dropping the engine and tranny again-eh)?

During the rebuild, I used the Zimmerman tutorial and my photo documentation of the removal process.