Top-Gun

So a bit of a sob story, I have a new to me 95 that I spent the last 7 months wrenching on to get it up to my picky standards. Drive the car once last weekend and loose the ability to get into 1-2 and R. While moving through neutral the lever comes up against something hard in the trans and will not move past the 3-4 plane. Only way to get over to 1-2 & R is following a sharp 3rd gear shift, this seems to dislodge or align whatever is causing the problem.

I've talked to many of the G50 experts and the common consensus is its likely a broken/bent shift spindle (reversing lever). Although I do plan to eventually remove the gearbox and ship it out for a pro refresh, its a real bummer to do this right now in the middle of the season. I'm also thinking if I can prolong the refresh for a bit I may be in a better position to look at a regear.

I've studied the manual and see theres a section showing how to pull the front cover and internals (i.e. remove 5-6 and R) with the box still installed in the car. At this point there appears to be nothing in the way of removing the mid case to expose the tensioning plate where I will hopefully find a messed up shift spindle.

My question is, is it feasible to pull the mid case and re/re the shift spindle while leaving the box in the car and bolted to the engine? Perhaps this is a dumb idea but I'm just thinking it would avoid messing with the clutch (which is new 5K ago) and would circumvent wrangling that trans around under the car on stands.

Pete Debusmann

No

You need to secure the input shaft (where the clutch is) to remove the nut on the other end that allows you to disassemble the gear box.

Pete

Top-Gun

Pete.

Thanks for the reply, would putting the trans in gear along with the e-brake applied be enough to sufficiently lock the input shaft to break the nuts loose with an impact gun? The factory service manual says something along the lines of applying 4th gear along with the handbrake to remove the nuts on the shaft ends (the ones torqued to 147 ft/lb and 221 ft/lb!). Perhaps in practice this isn't sufficient but it seemed feasible.

Rob

sonny1

The only thing you can remove is the end cover, which will give access to reverse gear., cheers, Sonny1.

Pete Debusmann

I don't know if that would work. It is way easier to just remove the tranny. If you take the end cover off the tranny needs to be supported since the mount is on it. If you remove the center cover you still need to support the engine/tranny unit. I'm not sure if you could get an impact gun in the space available. To get to the shift fork I think you have to disassemble the gear stacks. Sometimes long pullers are required to get the gears off the shafts. What if the problem is something else. A common problem is the needle bearings in the diff failing. The rollers wind up lodged in the plate that the shift rods go into preventing gears from being selected. Way to much work to do under the car.

Pete

pp000830

I would find a guy who works on these regularly as the key to a proper fix is an inspection of the internals by trained eyes with experience. In VA Robert at Lüfteknic Porsche Parts & Service is the guy for this job. Also I wonder what abuse could cause the speculative damage described in this thread. If other parts' geometry are potentially effected I wonder if you may be better off swapping out your tranny with a rebuilt example that has not seen such damage. My last thought is that I seem to recall that a clutch at the end of its life can have some baring on the symptoms you describe however I am not an expert so this is just speculation.
Andy

chaoscreature

TopGun,

Please check out these pictures from my rebuild.
http://s1292.photobucket.com/user/ch...?sort=3&page=1

Getting into the 2nd section of the transmission is not too bad and I honestly think you could do that while the transmission is in the car if you were really crafty... but if you expect to find something broken inside the center case you will definitely need the transmission out of the car.
- Peter

sonny1

Talk to Ivan at IMA motorsport,in VA.,cheers, Sonny1.

Top-Gun

Just thought I'd update my thread as I took the gearbox out and had a pro look at it. Problem turned out to be what was predicted, a completely sheared shift spindle. The broken spindle caused the reversing lever to jam up under certain conditions.

Luckily, Guard makes an improved replacement spindle so that's going in along with new bushings in the lever as the broken shaft tore the top one all to hell.

While the box was apart, my indy noticed the spider gears in the differential where also pretty torn up. Managed to source a low mileage G50 diff to harvest a good set of spiders out of (saves messing with the ring and pinion).

All in all a fairly simple fix. I understand the spindle is a common failure point in race G50's. I've also seen a few instances of diff spider gears chewing themselves up.