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'87 G50 Transmission problem

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Old 11-14-2010, 06:27 PM
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llangston1
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Default '87 G50 Transmission problem

I need some help diagnising the problem with my '87 Carrera G50 transmission. I can no longer shift it into 2nd or 4th. Reverse, 1st, 3rd and 5th work fine. This suddenly happened during the performance driving event our local club held yesterday. The transmission worked fine driving to the event. During the first wet dry oval event I started out and went from 1st to 2nd fine and was running around the wet side of the oval in 2nd when the instructor pulled the E brake causing me to spin out and stall the car. I suppose I did not get on the clutch fast enough since that was my first spin out. Anyway after that no more 2nd or 4th gear. The bottom half of the H pattern is gone. You can pull the shifter down but you feel no gears mesh and when you release the cluth the car is in neutral. I completed the even using 1st and 3rd gears OK and drove the car home using 1,3,& 5 and the car performed fine. No crunching sounds at all from the transmission. I just removed the shifter console and rear coupling inpsection plate and nothing seems out of the ordinary there. The shift rod pin in in place and there is no relative motion between the rod and the shifter mechanism. the large shifter bushing is still in place and not torn. There is a little slop at the rear coupler in the coupling bolts but nothing is completely loose or broken. So if it is not the shifter causing the problem what is the next likely suspect and does this mean a tranny drop and rebuild? Did I break a shift fork or something inside the tranny? There are no sounds like rocks crunching, etc from the transmission. How can you have R,1,3,& 5 without 2 & 4? Any body else had a similar problem with the G50 transmission? I need some advice fast since I need to try and get the car repaired before our December 4th DE at the track. Otherwise I will have to drop out and try to get a refund. If this requires a tranny rebuild should I go ahead and add a LSD while we are in there? Anyone know of a good G50 rebuild shop in the Houston, TX area?
Old 11-15-2010, 12:16 AM
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Carrera3.2LG50
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I wish you luck in finding the solution to your shifting problem.

Admittedly, I have not been to a DE yet and do not know the protocol with students and instructors, but you said this happened right after the Instructor pulled the handbrake at speed? Did you know he was going to do that at some point? If not, I hope he is man enough to pay for any repairs to your car.

Maybe I don't know what I'm talking about in regards to DEs, but I was getting angry for you just reading your post.
Old 11-15-2010, 11:18 AM
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llangston1
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I will let our club instructors and official debate the merits of pulling the E brake during a oversteer driving drill. It was just a wet oval where we they were teaching us the difference between understeer and oversteer. I guess the instructor wanted me to see the snap oversteer that the 911 could create so he pulled the brake to spin us out. It was my fault I did not get on the clutch quick enough to prevent the engine stall. I can't remember if it had popped out of 2nd into neutral of if I shifted in into N to restart the car but after doing that I could not get it back in to 2nd so I finished the drill and the rest of the school using only 1st and 3rd. Nothing seems loose in the shifter linkage inside the car so it must be something outside the car or inside the tranny case. There is only the one shift rod that comes out of the case. Surely someone on this forum has had this sort of problem in the last 23 years. what could break or hang up inside the case that lets R, 1,3 & 5th work but not 2 or 4th and no corresponding crunching sounds from the working gears.
Old 11-15-2010, 12:59 PM
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ron mcatee
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Does it shift Ok with the engine off? If it shifts ok with engine off, then I suspect it is the rubber centered clutch has disintegrated. That's what happened on my 88 Carrera. If it doesn't go through the gears with the engine off, then it's probably internal. when the rubber disintegrates it is flung outward and prevents the pressure plate from engaging/disengaging properly. With the engine off, all the rubber particles fall to the bottom. That's where I'd start.
Old 11-15-2010, 01:33 PM
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The Race Line
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I don't think that this is going to be a clutch issue, as you still have smooth running on 1st and 3rd gates. It is somewhat tough to diagnose without actually opening it up though. I would recommend getting it checked out and while it is out I do think you might want to consider a LSD.

Just my .02 cents

Erik Johnson
Old 11-15-2010, 02:22 PM
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llangston1
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Thanks for all the suggestions. Please keep them coming. It would be hard to believe that the clutch is causing the problem since the car ran fine driving home after the driving school. Also the event where the incident heppened was just a wet oval and we were only doing 20-30 mph if that fast when we spun out. Can the shift rod that comes out of the tranny case slip out of the coupler that sticks into the tranny tunnel inside the car? I know there is a bolt running 90 deg to the main shift rod that holds the coupler to the rod. Does that bolt stick through the shift rod or just allow the coupler to squeeze the rod? I have not checked that yet since i will have to jack up the car to get underneath it.
Old 11-15-2010, 03:12 PM
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sig_a
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Sounds like internal damaged since shift link works on 1,3,5. Perhaps you will need to remove G50 from car for evaluation, repair and a substantial service charge.

I've never heard of a qualified PCA instructor using that teaching technique to demonstrate 911 over steer. If he has any class, he will volunteer to pay for at least half of the repair charge.
Old 11-18-2010, 11:43 AM
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llangston1
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Default Tranny problem fixed

I got the problems resolved yesterday. It took a few judicious raps with a hammer on the rear coupler but whatever was jammed and stopping the shifter from reaching 2 & 4th gears cleared. Everything seems to shift fine now. No noises or crunching gears so I will hope whatever it was does not come back. thanks for all the forum suggestions.
Old 11-18-2010, 11:59 AM
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turbo911cm
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llangston1: Hammers are nice temporary fixes sometimes. I would have someone take a quick look at it. IMO I would want a second set of eyes as to what you hit and if your fix was permanent or just a symptom of a larger problem. I would pay the 1 hr shop service fee to have some more piece of mind.
Old 11-18-2010, 03:08 PM
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llangston1
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I might do the service call if I knew what they could service without dropping the tranny. Are the gear detents, etc. accessible through some access plate on the outside of the tranny?
Old 03-25-2023, 09:58 AM
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rajsekhon
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Default Torque down the three bolts that hold the shut rod housing to the tunnel

I believe your shift rod housing was not torqued down and moved south as you held on the shifter while car was in a slide. This would stop it from going into 2nd and 4th as the shift-rod would hit the tunnel housing and not engaging the gears. Hitting with the hammer moved it north. Late reply but might help someone!



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