I am in the process of my GT35R build. I bought a rebuilt transmission from a reputable source. I received it in the mail many months ago as I was preparing from my build.

The engine & transmission are now in the car as I began wrapping up the single turbo stuff.

My problem:

With the shifter in neutral, the engine & wheels still spin. I can shift through all of the gears except 5th & reverse, it simply binds and won't go in. Though 1st gear doesn't snap in completely, the shifter still has motion to it.

I have searched & found a few threads of similar problems. What some have said is that if the transmission is shifted without a shifter in it, the 5th/rev rod can be overthrown, causing it to remain in gear. Possibly happening during shipment. I'm not sure if this is my issue. Others fixed this by prying on the 5th/rev rod to put it in its proper position. I tried this with no success. It does the same thing as if trying with the shifter. It goes so far & stops. I tried it with the shifter in, & removed. It made no difference.

I pulled the pan to see what was going on. I made a video below that shows the process of going through the gears & the issue with the 5th & rev rod.


http://www.youtube.com/watch?v=gJ7zgR0hE-0

I will add that the clutch assembly is good & installed properly. With the clutch pedal pressed, the pressure plate spins freely as it should. But with the shifter in neutral, & clutch not pressed it still tries to spin the engine & wheels.

Any and ALL help is much appreciated.

 

I suspect the interlock mechanism isn't working right. The interlock is a series of bores in the housing loaded with check *****, spacer rods, and springs, and each bore is capped with a screw.

It might be as simple as a loose cap screw on one bore or a collapsed spring. I have not tried to service these with the transmission in the car. I suspect it's not easy. If you can pull the engine to troubleshoot this (before too much stuff is hooked up) it's probably a good investment in your time.

 

And this is my fear. I didn't think it would be a simple fix once I pulled the pan & saw what was going on.

I may consider leaving the engine in & dropping just the transmission. I have my entire front end torn apart & LOTS of work yet to do with my Vmount & oil coolers. This would keep the project moving forward as I get this transmission issue figured out. Once it's fixed, I could simply bolt it back up without disturbing my engine bay work.

Thoughts on this?

 

Also a perfectly valid plan.

This makes it easy to unbolt the extension housing and inspect the shift gates. If the transmission is out I'd do that before messing with the interlock. I suspect interlock more than the shift gates but I think either could be the root cause.

The interlock is not hard to work on. You need a narrow extending magnet and a touch of patience. It's easy to manage if you have the documentation in front of you and take notes as you go.

David

 

Thanks for your advice David.. Much appreciated.....

I have a FSM, but like most, my transmission experience is VERY limited. I'll consider either looking at it myself or taking it to a shop.

IR Performance is relatively close, as well as KD Rotary... I may give them a call.

I spoke with Rotorsports Racing, who rebuilt the transmission before I purchased it from a forum member. However, I would prefer not to ship it if possible..... Getting a box & paying shipping is a big pain in the rear.

 

I agree, take the trans out and leave the engine in. It's not -that- bad to put it back in the car (even on your back - use a jack and some wood to help line it up). If you have a lift + a friend, it's a snap.

If I remember right, once you have the thing out of the car, you can take the tail housing off the trans and manipulate the gear rods by hand. This should help you figure out if it's a problem with the interlock/detent ***** or if it's a shifter "gate" type problem in the shifter thingy.

I would also look for broken bits (like a tiny piece of metal or something) somewhere jamming up the works with the interlocks/detent *****. Working on the trans requires a bunch of special tools if you're doing a full rebuild - but just to fix this problem may only require normal sockets and tools - so it just depends what the problem is.

You may be able to fix this yourself if you just poke around at it for an hour or two once it's out of the car. Manual trannies are actually pretty simple, it's just some of the special tools that suck if you need to get some bearing off or something like that.

 

^Definitely, this was my thinking also. I have a lot of work to do yet,.... Not to mention a Rotary Extreme V-mount kit just sitting there, waiting to be played with

I do plan to at least pull off the tailshaft as David mentioned. If I can't see the issue after looking it over, then I'll resort to external help. I looked through the FSM to get an idea of what might be going on.

I'll keep the thread updated. I plan on pulling it tomorrow & seeing if I can get it sorted.

On a good note, finished up my fuel system today. All new rails, injectors, & Aeromotive FPR. Got the aluminum bracket fabbed & all is happy with no leaks. I really thought I was getting close until this tranny issue came up.... Hopefully it's nothing too serious.

Thanks guys!

 

Sounds good. I've put all of my transmission information at davidgeesaman.com

David

 

Thank you! Your site has some great tranny info. I've seen it before, but never thought I would use it... How ironic..

I have all day tomorrow to look it over. It's out of the car & awaiting dissection..

 

Transmission is out.

Once the tail housing was off, I inspected the shift gates, and all looked normal. The gates were aligned properly with nothing unusual. 1-2, & 3-4 rods still move as they should. 5th/rev still doesn't budge much.

From what I can see, I think it's just barely in Rev, but not sure. Please correct me if I'm wrong. You can see that the hub for the selector rests towards the Rev syncro. When I pull on the rod, it moves towards 5th, then stops. Does this look normal?

I also removed the cap for the 5th/rev detent. The spring came out but the ball is still in there. I don't have a narrow enough magnet to pull it out. I'm going to purchase one today. I turned the transmission on it's side to see if the ball would come out on its own. It didn't budge. This MAY be the problem.

From what I can see. The only thing that could stop the rod from moving IS the detent. The rod should sit & slide freely into each gear otherwise.

Below is a video

Any an and all advice is much appreciated.

http://www.youtube.com/watch?v=-IOIATLJSfM

 

And I think I found the issue...

My 5th gear syncro does not move freely.... It doesn't spin independently. You can see from the video that when moving the rod only causes the hub to slide & stop. Why? Because the synro is not lined up and will not spin.

I did get the indent ball removed. With the ball removed & could easily move the rod. This brought the hub up to be flush with the syncro. This is how I noticed the syncro wasn't spinning to allow the gear to mesh. It didn't seem to be an indent issue at all.

With this, I think the issue is much worse than just the syncro. With the 5th/rev hub centered, the main shaft will still not move. I think possibly the hub bearing has seized, causing the entire 5th/rev assembly to bind up. There is play in the shaft still, so it's very hard to tell. I am considering getting a gear puller so I can take apart the entire upper assembly. Once removed, I should be able to see what's going on.

This is all hypothetical,.. but there is obviously something going on with my 5th gear syncro. I hope it is centralized in this spot, & not anywhere else.

Thoughts on this?

 

Well, you should be able to turn the main shaft. Be careful once you remove the detente ball that you do not move the shifter rod too far. Try to get the ball free while holding the shifter rod and see if you can get the shifter rod into proper position. But, it still does not explain why the main shaft does not turn. Can you get ahold of the shaft with a levering tool (do not gouge it or use something w/ teeth to scratch it) to see if it will turn? Otherwise, something is assembled wrong if it will not turn even if in gear.

 

After looking at the videos a half dozen times, the fifth/reverse syncro (the gold ring) is not aligned correctly. It may not have been properly positioned with the fifth/rev hub. Try to move the synchro around (which I doubt will happen) to align w/ the hub gearing. If not, then you will need to disassemble to the syncro and get it in the proper position. Something is assembled wrong there. It is causing the fork slider to catch on the opposite side and is not letting your shaft spin.

 

The slider fork should be able to slide across and nest into the synchro. AS is obvious, the synchro is out of alignment and blocking that movement. Your rebuilder assembled this wrong. Just look at the 1/2 and 3/4 hub and synchro alignments.

 

^Agreeing 100%

Even with the endent ball removed, the rod doesn't budge. It moves just a little, but not much.

The 1-4 gears syncro's move freely. The 5th gear doesn't move one bit. In fact, it almost seemed seized.

I'm pretty pissed about this whole ordeal....

Thank you for your help. I am debating to disassemble it myself or just send it to a shop. From Dave's documentation (which is awesome btw), it doesn't seem too far from my scope of ability. Just have to get the bearing puller & order the new ones, as they will be destroyed when you pull them from the race.

And of course whatever parts are damaged... if any.

 

You can devise the long bearing puller if you have any mechanical aptitude at all. I and a buddy devised a puller by just capping off a 1" pipe (weld on flat steel and grind to taste) and threading a 5/8ths bolt through the flat end. At the bearing end, you just need to devise a way to attach normal bearing puller arms (assuming you have a puller already with detachable arms) and go to town. The bearings are more durable than you think. There is no reason to assume you will damage them. Just be sure your puller is pulling evenly on all sides (two or three depending on what you devise). The bearings will most likely be reuseable if they are new now. And yes Dave's thread is awesome. Follow it on the disassembly to the synchro and reassembly. I taught him everything he knows. [HaHa--Dave].

I'll try to post a pic of my puller tomorrow.

MOST IMPORTANT CONCEPT: THIS IS NOT THAT DIFFICULT. YOU WILL FEEL LIKE A REAL MAN WHEN YOU HAVE ACCOMPLISHED THE REPAIR YOURSELF!!

 

When you got the detente ball out were you able to move the shifter fork into 5th gear? And then did that free the main shaft so it would rotate? I think you should be able to move it into 5th gear. Go easy with the detent ball out though.

 

Thank you for the great advice man. Yes, I'm going to give it a shot. Not much intimidates me, but I just want to make sure it's done right. Only way to know for sure is to do it myself I guess

To answer your question, No. I got the ball removed and the rod still would not budge, nor would the main shaft turn. If I look closely, the misalignment of the 5th gear syncro is stopping the hub from sliding into 5th. If the syncro was moving as it should, it should pop on, but it doesn't move at all.

I also find it unusual that I can't push the rod into reverse either. As in, pushing the rod in would put it in reverse, and pulling it would put it in 5th. Neither one will budge, nor the main shaft turn.

I'm worried the hub bearing is seized and it has scored the main shaft. If this is the case of course it will need a rebuild to replace the main shaft.

I plan to take it apart tomorrow. I will go easy with everything.

 

I guess I had 5th and reverse "reversed". So pushing down or into the direction of the main box goes to reverse? It maybe because of the idler gear I suppose. In any event, you cannot move the fork in the direction of the main box and get it into that gear? MMMMM? Going to need to ponder that. Be very interested to see what you find when you get it apart.

Yeah, if you cannot get the collar to move across the hub properly, the main shaft will not turn. The collar is bridging the separation necessary for the main shaft to turn.

 

Yes, this is correct. Looking from the rear to front of the transmission, the 5th gear comes first, with reverse sitting in front of it. I really can't see much of what is happening with reverse because of this. It's kind of buried.

It's very unusual. It's not "in gear". All 3 collars are sitting in the center and not engaged with any gear. The fact that I can't shift to 5th or Rev and the syncro not moving is really a moot point considering the main shaft does not turn. All in all, it's funky business.

I have received a PM from the seller regarding this issue. He is making restitution & has offered me a valid option. With this, I am simply going to reassemble what little I have taken apart & go the route he offered. A lesser man? Maybe.... But it's just easier to take another fresh working tranny over this seemingly possible cluster fu*k.

Thank you for your help and advice. In a week, I should be well on my way to firing up my single build with a fresh transmission. Hopefully, this mishap will be far behind me.

 

Absolutely take the option. The tranny should have been working. It would be interesting to know what the rebuilder got wrong. Good luck w/ the car.

 

^ I know what you mean. I too am very curious. The seller plans to rebuild it likely. If I find out, I'll update the thread for informational purposes.