VGLNTE1

My stock Mn6 has been perfect for 9 years. I recently switched to Amsoil aft and took it to the track yesterday. On the 3rd turn after some Gs it gets stuck in 3rd. I fiddle around and get it into 4th. Locks in place. So I ran a 20 min session just in 4th. I park the car, and let it cool. After 2 hours it shifts like butter again. I take it back out. Boom, locks in place by the 3rd corner. And then it locks there permanently. Just a coincidence, or.....

SouthernSon

Man, that sux. Hope you can get it repaired without too much pain. The amsoil in my Allison tranny seems to be running as strong as ever. Maybe you can do a good forensics teardown.

brkntrxn

I doubt it has anything to do with the fluid. Sounds to me like you have a key floating around in your gearset.

drivinhard

coincidence

Mark2009

Amsoil makes about a half dozen different auto transmission fluids... it would help to know exactly which one you used (only one, as I understand it, is specifically for Dex III use).

Hi Volts Z06

9 years out of a gearbox you track? I'd say you did pretty good. Have a reputable company that does road racing trans work rebuild and ask what fluid they recommend. I have tried various different ones but the real key is a nice big cooler.....that's what's most important.

VGLNTE1

Ha, yes. Still the stock 02 trans. Used to drag race it, and have been road racing for 3 years now. And that's with a 4.10 gear and 600 hp. These t56s are so impressive.

Scooter70

Coincidence and/or the fluid change made some previously loose parts move around. Sounds like a rebuild is in order. Mine did the same thing. Result was worn synchros, broken key, and a broken tooth on 3rd gear. D&D did the rebuild with some upgraded parts and it's been great since.

froggy47

I agree with above it's probably not the fluid (unless the wrong one was put in).

I use only Redline d4atf.

First thing I would do (after verifing the correct Amsoil is in there) is a shifter alignment. Out of align or loose shifter could give you issues. When was the last time it was done?

VGLNTE1

I checked the shifter, it was solid. It's never been adjusted in 7 years. No clue how you would even do that. The linkage has a spot for the bolt to go by...how do you adjust that?

froggy47

Skip to 7:00 on film.

RX-Ben

Alignment is super critical. If not very well aligned you cannot get a new trans into certain gears and it feels crappy unless alignment is perfect.
Your rubber bushings on the shifter base are also probably shot too.

fatbillybob

People always say this. Maybe you guys can school me. Look at Froggys video. My C5Z is exactly the same as the video. There is no play in the shifter. The bolts have zero play. You just bolt it in and the shift rod locks in the detent of the shifter boss and the unit falls right in the tunnel boss. There is nothing to adjust. How can this be so precise? What am I missing?

SouthernSon

http://www.coloradocorvetteclub.org/...rinyourC5.html

Apocolipse

Amsoil and redline make great fluids. I run redline d4 ATF personally...

froggy47

You loosen it up

Pin is in

Alignment happens when it's loose

You retighten and shifter has taken a slightly new position which will result in gear(s) engaging more precisely when shift is thrown

We are talking 1-2 mm chg here.

The procedure is not a "fake" procedure, it's for a reason (tolerance wear)

It is meant to be done, even when you do not find anything loose. It has helped many people, try it, however your tranny may still be kaput Hard to diagnose on internet.

VGLNTE1

Afraid it's to late to try this now, but I'll take a look when the new one is in. I switched to delrin bushings a while back.