Looking to replace the fluid in my 99ss and it says dexron III. Went to the dealer and they said that Dexron VI replaced it. from the post that i have read this doesnt seem correct. Anyone know what the deal is.

 

Either one will work.

 

actually just spoke to a tech at tremec and they said to use the gm syncromesh (GM 12345389) or penzoil who makes itfrom gm also has a syncromesh and I should use that. They recommended that over the DEX VI. abyone have any other experiences with this, I know there have been plenty of treads

 

Just did the fluid change this weekend. Seems grindy until the fluid warms up. Is this normal or did I waste 35 bucks on syncromesh and should go back to the dexron III

 

I'm at the point of changing my M/T fluid too... how is the synchromesh? OR do you recommend Dex IV?

 

12345349 gm part number

 

I used Dexron VI a few months ago in my trans fluid change. Everything works fine as far as I know.

 

I have run only Castrol GTX Dexron III/IV in mine since I rebuilt it. Seems fine. All my other fluids are full syn though.

 

Any time you see a spec for Dexron, use the latest version. It supercedes, is compatible and replaces all the versions before it.