e9stibi

I already posted on the 993 forum on the break down on my custom 993 C4S G64 gear box. I lost 3rd/4th gear and assume that there is an issue with the shift fork. I hope this is the only problem.

The gear box has been built by Rothsport in 2003 and has about 25000 miles as the RS clutch and fly wheel. According to the invoice, I got new 1-5 gear with shorter ratios and the stock 5th gear has been moved to 6. Material costs where about 4500 USD and I hope this good stuff is not further damaged. Both forks and synchros remained stock (brass).

Independent of any further damage (keep my fingers crossed), I already decided to go to steel synchros for 3rd to 6th gear. I am not using 1st and 2nd gear on the track and stayed away from the $$$ to do the steel synchros here.

I know that I will upgrade to a billet shift fork for 3rd and 4th and are not finally decided on 1st and 2nd because I do not use those gears on the track. What would you suggest?

Is there anything else that you would replace "by default" independent of damage or wear?

Final question would be who you recommend to to the job in Houston?

Thanks
Erik

P.S. The good news is that I could shed another 4 seconds of my best lap time on TWS (2:06, CW) on street tires. The test and tune event on Friday was big fun until I "shifted into the empty". Hope that the DE on Saturday and Sunday went well for the others. Damn, I was ready to go ...

Robert Henriksen

Best recommendation I have is to crate it up & ship it to this shop:
=============================
"Company's name is BMC&G, owner is Brian Copans and he or his wife are the only "Employees". He is in West Chester, Ohio phone # 513 779 3302. He is probably up to his waist in race car transmissions for the upcoming races in the ALMS and Grand Am so if you are not serious about having the work done or are just trying to pry him for info, he will probably not give you much time or interest at this point. Also being extra nice to Pam will get you brownie points.

He is one of the best but if you are on a tight time frame you might want to find another shop. He's race team customers come first unless it is in the off season. "

e9stibi

Robert - thanks. When I did some research, his name showed up quite a lot. I am not on a really tight schedule but are thinking more in 2-3 weeks than months. I will give him call.

Any experience with transmission work at Rennsport (Mike Callas in Seally)?

Bump for other suggestions!

U4EEAH

Copans is the BEST, but think months not weeks. Up north we have 3 months down time, a "luxury " you don't have. Upgrade the 1/2 fork no matter how little you use them, it is most problematic in these boxes

e9stibi

Waiting for it months is not acceptable at this time. Thanks for the advice on the shift fork. This is consistent with what others have told me.

Bill Verburg

besides the shift forks there are other internal parts to consider beefing up

syncros -steel
shift spindle 950.303.134.05 is a much stronger part
GT 1/2 billet shift fork
GT 3/4 billet shift fork

You might consider contacting Matt Monson at Guard Transmission or Chris Cervelli in addition to the great previously offered suggestions

e9stibi

Bill - I plan to do the synchros (3-5) and the billet shift forks. Shift spindle is a good recommendation, too. Should I think LSD???

GTgears

Bill,
As always your endorsements are really appreciated. However, I do want to add one correction. We don't manufacture a 3/4 billet shift fork. We sell the factory steel version as a replacement for the stock brass piece.

I will second the recommendation on Chris Cervelli if you can't wait for Brian to get to the box.

Based on the description of the issues, hopefully it will be no more than fixing a bad fork, though the 1-2 billet and the upgraded spindle are both good "while you're in there" items. We manufacture our own spindles which are both stronger than OEM and cheaper.

Fly911

Rennsport (Mike Callas) is a no brainer. Give him a call on 979-885-7304. He knows the G50 inside and out, he can do it pretty quick, and is reasonable priced. Mike is known to be one of the best air cooled Porsche mechanics in the US!!!

Bill Verburg

I must have old out of date data sheets, even on those it does mention limited availability of the billet parts, the factory 3/4 fork you provide must be the g50/30&32 version

GTgears

That's the one. 950.304.113.04 I believe.

e9stibi

Thanks to all of you for the help. I will keep you posted how the "project" goes.