phil@tech9

guys,

with reference to the differences in 'driveline shunt' between a T4 and a C2, the engine and gearbox is mounted differently.

Both models have hyraulic damped rear engine mountings, but the way they are fixed at the gearbox is different.

I am not sure exactly when it was introduced, but on most 993 C2VR and RS and GT2 models that I have seen, they have a pair of braces that secure the gearbox mounting to the chassis.

These braces are fixed onto the bodyshell under the rear seat area. It would be an idea to retrofit these parts, as it would definately help with your problem

pilon

I have a 1996 C2 and I am having the same gear problem, as second gear pops out when under engine braking (either from letting go of the throttle while driving on the street or during break application comming in to a turn if 2nd is engaged)

If any body knows what is the potential problem, this could help me out a lot.

I will try to get the tranny mounts checked out but my intuition tells me it is inside the tranny (I would probably be seing this on other gears)

goofballdeluxe

Wow, an 8-year old thread brought back to life!

flankenspeil

The problem is not your driving. The problem is the mis-adjustment of the "z" shim inside the transmission. I have seen this on several gearboxes from the factory(new). Funny that there is no adjustment procedure in any manual, but when assembling a transmission, the center case section has to be in place to measure the z shim. Therefore you need a case section with a cutaway (homemade) in order to measure and adjust the 2nd gear set.

Nollie

My 96 C4S was popping out of 2nd gear under hard breaking going into corners during autocross. Not compression breaking. When I had it rebuilt my operating sleeve was toast, and my syncro wasn't very healthy. But I'm going to blame that one on the nut behind the wheel.

NC TRACKRAT

"When I was at Skip Barber I brought up the topic of engine braking. Or more specifically Trailing Clutch Oversteer (TCO)".

Long time Skip Barber graduate here. Just to clarify, believe the term is the dreaded TTO, Trailing Throttle Oversteer, which, if induced, can really bite you in the butt, especially in a rear wheel drive, rear engine vehicle.

Martin S.

EJ writes, "BTW - if you have time to engine brake at the track, you're not going fast enough. " Can't agree more.

Engine braking is for diesel rigs, not Porsche cars. In the days of old, MG and that ilk of "race" car, the brakes were nowhere near what you have on the 993...

We drive at Auto Club Speedway in Fontana, coming into Turn 3, a good running 993 car is going 135 to 140...need to brake down to about 55 mph to turn in....I have 993 Turbo Big Reds with Pagid Yellow or Pagid Orange front, Pagid Black rears. Our sessions are 20 to 25 minutes long....the brakes never even fade.

The ***** in the Porsche G 50 tranny, IMHO, are the brass synchros. I have had two separate 3rd gear synchro failures...have since replaced the brass with steel, sweet.

I also installed the factory SSK from FD Motorsports as well as their tranny stabilizer bar, the bar that goes forward off the G-50, beautiful piece of art...but that's what you get with Darin Fister.

I also installed 993RS motormounts and a 993 RS tranny mount...the verdict, she shifts like a "hot Knife through butter". BTW, I am using factory shifting forks...some replace these with aftermarket forks, stainless steel and or titanium.

Kacey

I'm having this issue since i lowered the car 2.5". When I keep it in 2nd in tight twisties, sometimes the lever pops out of gear. It's seems as though the 996 guys have this issue as well and Gbox offers this as a fix. Has anyone tried it on a 993?

www.gboxweb.com/detent.html

trophy

That fix is for the standard Carrera transmissions and not the G50 or derivatives of (Gt3 etc)

Paolo1

What do you do to replace the brass synchros with steel? Does Porsche offer upgraded parts for this? Thanks.

Martin S.

"What do you do to replace the brass synchros with steel? Does Porsche offer upgraded parts for this?" You local performance shop can order steel synchs for you. 1st and 2nd, may already be steel, that's what I was told... generally folks go brass to steel on 3rd, 4th and 5th, maybe 6th on a short geared tranny.

This thread originated many years ago, so many, so very many.....

Paolo1

Thank you for having retained the subscription to this one and re-joining with great insight. The search feature is a wonderful tool for finding meaningful old discussions. Downshift from 3 to 2 is my issue so it looks like steel is already the OEM standard there.

GTgears

No, 2nd doesn't have steel stock, its brass like everything else.

Gt3 Cup steel motorsports Synchros fit 2nd. For 3-6 gt3 street and cup use the same steel synchro. All will work in the 993.

Paolo1

Would this be overkill for street only use? I plan on keeping this car forever and never want another issue. I wonder why my Porsche only local indy did not propose this...must be a good reason, right?

Martin S.

Good stuff, thanks for the update!!!