Originally Posted by ram_man
What I don't understand and it's causing some fear is that the car calls for Dex 3 I know the synchros are the fiber material and are not brass. So I want to make sure that whatever I choose won't eat those up and cause big issues.
I'd make sure to buy whatever fluid is safe for carbon or fiber based synchros, my guess is that a all synthetic based fluid will be best to prevent wear most effectively.
Also make sure it is GL-4 only and not GL-5 since added sulfur probably is just as likely to wear harder on fiber based gears as the brass/bronze gears.
It's not easy to find specific info regarding which fluids are best for carbon and other fiber based synchros. Although I'm sure that you do NOT want to use a GL-5 spec fluid for sure.
I wonder if Pentosin MTL-2 would be your best bet?
I'd send GM technical center an e mail and ask about this. I'd be interested to know the answer as well!
OTOH CALLING MOLAKULE....
....so Mola, what can you tell ram man about what fluids are best for these fiber based synchros. Mineral or all synthetic based, and I assume you want a GL-4 only fluid as well.