Transmission question
Thread Starter
Race Director
Joined: Feb 2006
Posts: 10,336
Likes: 14
From: Bellville OH
St. Jude Donor '06
Transmission question
I posted in C5 gen and they revered me here. This is the thread with my question:
http://forums.corvetteforum.com/show....php?t=1762665
http://forums.corvetteforum.com/show....php?t=1762665
The other day I had Royal purple put in my 99 Coupe all the way around transmission, engine and the coolant additive. Then tonight I read in the Tech info that synthetic ( royal purple was specifically listed) Would ruin some kind of paper seals which would in turn ruin the transmission (6 speed) How long does it take, Is it that serious? How much would it cost to have these things looked at to see if I even have these paper seals. I've driven the car 100 miles on the purple and it seem to shift smoother an idle better I'm 
right now.
right now.
Melting Slicks
Joined: Jul 2006
Posts: 2,094
Likes: 4
From: The 7th layer of hell - Western Washington
Out of the C5 General Sticky
Manual transmissions -- Replacing the transmission fluid often helps shifting. Early transmissions have paper blocker ring that require Dexron III compatible (usually organic) fluid because some synthetics will destroy the paper blocker rings and subsequently the transmission. Later transmissions, and all rebuilt transmissions, have Kevlar/carbon fiber parts that allow the use of synthetic fluids. I believe the 98-00 transmissions have the paper blocker rings. The safe transmission fluids seem to be: GM Synchromesh PN #12345349, Honda ATF-Z1, Royal Purple Synchromax, Amsoil ATF, O’Reilly Dexron III ATF. The following transmission fluids may be unsafe for early transmissions: Redline D4 ATF, Mobil 1 ATF, Royal Purple Max ATF.
