Ok I will try to assist on the ISV. Just remove the ISV and look for the set screw that is hidden under the blob of clear epoxy. Use a grinder with a wire brush attachment to remove the blob. Reinstall the ISV and have a friend rev it up to say 3-4 k and then slide their foot off the throttle . As they do that rotate the set screw(cant remember which way, been too long) until the ISV catches the car nicely at around 5-6 and brings it back to normal idle. This will solve the problem and the car will work fine from that point on...

 

Update!
After all that repair, I discovered on the autocross first run the problem occured again. Could not shift to 2,4,6 at all. Recently, I had transmission build with new syncros etc but that turns out was not the cause as originally suspected by mechanic.

Also I noticed, its little weather releated, happens usually on warm day. Gears loosen up over time.
I wonder if its the spring, or something else. I did relay all the information you guys suggested to the mechanic but he did not think it was it.
I am thinking of cancelling the credit card charge, since the shop never resolved my problem, and have some other shop look at it.
-Kadeer

 

Kadeer,
Send me a PM. I will refer you to one of, if not the best Porsche transmission shops. Or if he is too busy he can get you to someone reputable in your area.

 

Remove gearbox, place in large Coleman cooler and send to Brian Copan. Make sure to regear this time . It can be done very reasonably per my earlier notes. PM me or call me at 972 672 9986 if You need help.

 

My thoughts are exactly the same as Glen's. Only thing is that he is so busy right now that I am not sure he has time to do any gear boxes for anyone other than his race clients. His shop looks like a transmission warehouse.

He is the best and very reasonable, but if time is an issue he might refer you to someone fairly local.

 

Make sure to at a minimum, talk to the shop who did the work and try to reach an agreement. Do this asap as everything should be fresh in their minds...

 

Did he ever change the part I told you??? If he did not even check this part that WAS the solution to the same symptoms you described in my gearbox then what can I say... To me its mind boggling to dismiss an actual solution to a similar problem just because he did not "think" it was it... I would be furius right now...

 

Danny, I gave this in writing to the mechanic, he recognized what it was but he said it was OK.

"The Rennlist members group have pointed a fix who encountered similar problems on the 95 993.
Here is a list of possible things and their solutions.
(1) There was a small 20 dollar part that sits in the forks and guides the gearchange. The part is in 2 pieces with a spring inside and this part ( half the size of your middle finger) when compressed manually by hand at a certain angle it would bind. Part is really small , the diameter of a thin pen about 2 inches long. This part needed replacement. Rich, my symptoms match this persons issue so I am leaning towards this as the solution.
(2) In the gearbox some discovered that the shifter forks had loosened and were out of alignment.
Others related to Shift fork or linkage issues."

 

I bet he did... The binding on this part was only on 1 specific position. ANY other position and the part would work fine. I had it in my hands and I played with it much like you play with a pen clicking on and off. The part was working at most of the possible positions! I saw it by myself! My mechanic even was not sure because the part was working most of the time but being the honest man that he is , he told me clearly that there was nothing else wrong with the box that could produce this problem and while he was not 100% sure this could be the culprit , the part was very cheap not to give it a try. That part is the only thing he changed in my box and the problem is history!!! And yes my box still has worn synchros, when you put it into 6th it grinds like crazy but worn synchros are not what caused the problem and I'm 100% convinced of that. Heat does not cause it either...
In my view your mechanic should open the box FOC and replace infront of you ( for you to be sure) the part with a new part recognizing his possible mistake for dismissing your suggestion. If he wants to keep you happy the only expense that you will bear will be that 20 dollar part. If nothing else he is responsible for not fixing your problem in the first place and 6 grand later this is the least he could do...

 

Like Danny said, its not really smart to tear into the gearbox and find nothing wrong, then reassemble without at least taking the free advice from a collective knowledge base and replace this part, ESPECIALLY since it costs less than the oil in the gearbox

 

I called the mechanic Monday 9:30am and told him the problem exist, he said he will get back to me. Its Thurs evenening no call.
Funny thing, I took it to another mechanic to document the existence of the problem, for the life of me it would not appear for that hour. Soon as I returned, there it was again. I have not found a way to instigate it.
High rmp, hard braking, cornering, warming car, - it appears when it wants.

How much do you think someone should charge to put only this part in ?
I will get it done elswere and cancel the visa payment.

 

That is exactly what was happening with me. I could not duplicate it for the life of me and one time I took it around the back roads by my mechanic's place and again for the first hour nothing! I would row back and forth on all gears and nothing... TILL I started braking really hard both engine and brakes and then it happened! Again it loosened up and infront of my mechanic's shop I braked very hard from 70mph and I was lucky enough that it replicated. Ofcourse by the time I drove in the driveway of his shop the box was loose again... Still my mechanic went with what I told him and you know the end result...
In order to put the part in you will be charged labor for opening the box again which as you know its a lot of money....

 

To bring new life to this thread the other day, I lost 2nd and 6th gear (4th seemed fine). The gearbox doesnt make any weird noises but it seems the gears are just gone! (not in the box at all) and then all the sudden.. I take a corner and BAM! gears are back and they go in fine and when its in 2nd or 6th it doesnt make any weird sound it actually sounds perfectly fine...

I am guessing its the linkage or shifter fork problem. The thing is I have a perfectly good gearbox sitting around except for a blown R&P and this one has what seems to be a bad gear section.. How hard is it to take the front part of tranny and bolt it to the back part of the other tranny?

 

I just got back from Gingerman Raceway where I had the same problem on my 1995 C4. Has PORSCHE made in upgrade which is why this seems to happen on mostly 95's. Does anyone have the part number. Also has any do-it-yourselver taken out the tranny before, if so how many hours should it take a non-professional?