jsottile

I need help determining making a decision to for my C5 Corvette Z06 transmission. The car only has 12,000 miles on it but the synchro key went in 4th gear. Based on the mileage of the car, I don’t drive the car that often and I typically drive it on the street and I do around 3 to 6 HPDE events a year. I have other sports car and plan eventually to make this strictly a road race car (not anytime soon). The rest of the drivetrain is stock (clutch, diff, etc.) and no major engine mods. Eventually, my max power levels will be 600 to 700. One track that I run is VIR and last year I was getting the high transmission temperature warning light. Right now, I don’t have the budget to do everything I would like which would include a differential upgrade, differential cooler, clutch (the stock one is fine for now), transmission cooler, etc. For now, I just want to focus on the transmission. So I am looking for suggestions on what route I should go taken into consideration budget and also future needs. Also, I live near Pittsburgh, PA so I have various options within driving distance. What are your thoughts on the following:

1. Option 1, I pull the transmission and take it to Phoenixville Corvette to have them go over the transmission. Not sure of what the price would be but they said it costs a minimum $500 in labor to split open the case. Overall, I would say this would be my cheapest option assuming no major issues with my current transmission other than the keys.

2. Option 2, drive the car to RPM Transmission in Indiana and have the a Level V T56 installed.
3. Option 3, drive the car to RPM Transmission and have a TR6060 installed with the conversion for using the stock C5 diff. (this option is getting a little expensive but is it worth it for future upgrades??).

Some other questions:
1. I was planning on have the mechanical cooler pump installed on the Level V T56 upgrade. This does push the price up to $3,200. With the price of a TR6060 exchange costing $4,400, it is worth the extra $1,200 to upgrade to a TR6060?

2. If I get the TR6060, how weak will the stock C5 diff be and is it a worthwhile upgrade if you are not also doing a C6 Diff upgrade (which then requires the new cradle, etc.)?

3. For road racing purposes, should I get a transmission brace and it so, which one?

4. If I get either the Level V T56 or the TR6060 from RPM, I will probably just have them install a loop for the cooler until I can afford to put in a tranny cooler. Do you think running either transmission at VIR without a cooler and without a diff cooler is a bad idea until I have the money to install the coolers (which will not be this year)?

5. Anyone ever have a transmission worked on at Pheonixville and how it might compare to a RPM transmission?

Thanks

waddisme

With no more mods than you have and the way you use the car, the RPM seems a bit overkill. Don't hear much of manual trans having issues other than pilot bearings. My car is heavily modded and tracked 10-12 times a year. While I had it out repl pilot bearing, I sent it to Tick Performance in Mooresville and had their Level 1 upgrade for like $1300. According to them, that should suffice for my needs. Just drop tranny in plastic tub and ship to them and they handle the rest. It would be a good middle ground choice. Good luck with it.

AU N EGL

Phoenix Performance does first class work.

They are the Road Racing gurus of the east coast

sperkins

Mn6

Bill Dearborn

Have the transmission repaired to and add transmission and diff coolers. The C5 diff should be strong enough for what you are going to do. I don't think you need the diff brace as you aren't planning on drag racing. A lot of people have run that setup for years and have done well with it. Keep both the tranny and diff cool and they will last.

Bill

sothpaw2

I had this exact thing happen to my car right after I bought it at about your mileage. I sent it to RPM trans and they rebuilt my exact trans (not an exchange...I waited for mine) and gave me a price break. I got the better keys and shift fork and a few other goodies for $1200. It's easy to ship to them; call them and they will give you the details. You have to take it to a freight place and freight it on a wooden pallet. Buy some straps to strap it down on the pallet.

It's been 5 years , many DE events( about 3 per year) and I've had zero issues with RPM's work. I just run Amsoil in it and avoid long sessions on hot days. Highly recommended just rebuilding your stocker.

C66 Racing

Suggest option 1. Joe and his guys have been doing the hard maintenance on my car since they prepped it for SCCA T1 in 03. They have rebuilt my tranny for me twice and it worked great both times. Almost sent it to them again this offseason but decided to roll the dice and run it another year before a rebuild. They can do upgrades to your tranny that make it more durable (and they have done to mine). I trust Joe enough that I have driven 3000 miles to take him my car...

For DE's you may be able to get away with this, though I got a high temp warning my very first DE in the Z06 way back in late 01. I had Phoenix install a tranny cooler in mine which is compliant with SCCA T1 class rules when they prepped it for T1. If you get a tranny high temp warning, I'd come in and let it cool off.

When you're done with whatever option you chose, I use and recommend this fluid. The Torque Drive will not shear down and lose viscosity under the shear forces it sees in our trannies - overall I think it is the best option to help protect against the high temps you are likely to see:
AMSOIL Torque-Drive Synthetic Transmission Fluid (Product Code ATD1G)

travisnd

Brad do they sell the torque drive by the quart? I've always used the synthetic ATF from Amsoil. Is the torque drive better stuff?

C66 Racing

No, only by the gallon.

The Multi-Vehicle ATF (product ATFQT) which is sold by the quart, and the Torque Drive ATF (product ATD1G) are very similar and both meet the now superseded GM Dexron III spec which was the spec for our manual trannies. When GM came out with Dexron VI in about 2007, AMSOIL took at hard look at is ATFs. As a result they ended up coming out with a new low viscosity Synthetic Fuel Efficient ATF (product ATLQT) for the Dexron VI market, but they also changed their recommendation for the Tremec manuals from Multi-Vehicle ATF as primary and Torque Drive as alternate to the opposite, Torque Drive as primary and Multi-vehicle ATF as alternate. I've used both over the years and really can't tell the difference. I think the Torque Drive as zero viscosity improvers thus is probably more shear resistant, but they both use the same basestock and are both very shear resistant so it might not matter, particularly given how often track guys change the fluid. That said, I've been using the Torque Drive since they changed their recommendations in about 2007. They still do recommend the Multi-Vehicle ATF (as alternate) so I wouldn't run out and change it.

Actually for me the Torque Drive is handy as my tow vehicle has an Allison tranny which takes the same fluid so I order it by the four gallon case.