Royal Purple Syncromax SUCKS!
 

Changed the M6 trans oil last week with RP syncromax and the next morning when it was cold out I could barely get the car in 2nd.. Its been that cold before with the OEM oil and never had that type of a problem.

What are the options? go back to OEM, Amsoil, any Additives..

I read 3.65 Qts so I took out 12 ounces from the last bottle.. that left me just under and not dripping out the fill hole maybe a 1/16th or 1/8th below the fill hole.

When it warmed up it was OK.. I'm talking 45 degrees my garage is always about 60 degrees..

By the time I got to work it felt ok, but when I left for home it was hard to go into 2nd I'm mean really hard..


Never had that with OEM stuff I driven a lot in cold with it!

Sorry to hear this. I went to Synchromax a year ago and its been fine. However, I have always had to watch the 1-2 shift on cold mornings. RP didn't change that.

Thanks for the info. I called Tremec, he thinks its because the oil is thinker its harder to push out when cold. He said thicker is better for racing. He also recommended the GM fluid since it has some parts to there specs and Mobile 1 ATF synthetic. He also asked if it was better when it warmed up and how long it took to feel better.. he also recommend letting warm up which i dont really have time to do most of the time. I do let everything warm up before I beat on anything though.

I dont know its 70 today I may see if it's ok today.

Ouch. I have 4 quarts in my garage...

Been using RP oil for years with great results.

You forcing thru the skip shift lol??? :bonk:

That's the 1sr thing the tuner got rid of lol

I ran Syncromax for awhile, and ended up switching to Amsoil ATF as it was easier for me to get locally. I think the ATF is smoother, but not by leaps and bounds.

However the Syncromax felt better when it was fresh, but after 6k miles or so, it didn't seem to be as good as when it was new. The ATF thus far doesn't seem like it has faded at all (about 4k in driving)

Sorry that it didn't cure the 1-2 shifts for you but I appreciate the feed back as I was debating between RP Syncromax and the Red Line D4 ATF, in which I will try the D4 now after hearing your 1-2 shifts are harder.

I do have the issue as well with getting my short throw into some gears, like your forcing it here and there but tends to clear up pretty quickly. I thought I was the only one, i might change as well now :(

Best advice I've read on the site lately regarding the 1-2 issue is after starting up, run the shifter thru the gates a few times- esp. the 1-2 shift before you begin driving. It just takes a few seconds.

Seems to really reduce my 2nd gear "hang-up"! :nod:

I ended up just purchasing the stock fluid right now, i did a clutch swap the same time i did the trans fluid. I'm going to see if Royal Purple is at fault for my hard to do shifts, i don't track my car or drive it a lot so i don't care what i put in it as long as it works... I'll probably go amsoil next go around though.

Whatever OE oil is it works great cold through hot. Perhaps RP is more suited for warmer climates or track only where you can let car warm up ?

Maybe it will shear down after some use?

Next time I'm going to try Motul 75-90w 100% Ester Synthetic. I put the 10-40w version in my motorcycle this summer (Yamaha FZ09) and it went from a good shifter to a GREAT shifter! A really noticable difference and it has stayed that way.

Has anyone tried the Motul in their car?

I’m using rp. No complaints. Not sure if it was worth switching, I’m not positive but I think it lowered my mpg! I bet it thins out quick and will get better.

As I’ve said for a long time I usually skip second gear unless needed and I never need it while I’m warming up the car. I keep getting flamed on for this, but I don’t see issues.

How often u bleed ur brakes?