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I know there has been several topics of discussion about this but they're all fairly old.
Since my 2007 isnt under warranty, I don't have to always put the GM stuff. Not to mention the GM shop is open 9am to 3pm M-F, and i'm always working during those hours.
I read alot here and it seems that the Royal Purple Synchromax is highly recommended for our MN6 trannies, anyone been using this fluid since a while and has no problem at all ?
I have used Red Line for 15 years. Put in my C6 at 1,000 miles. Red Line only uses premium ester stocks, so it has more stability at higher temperatures.
Their products work so well that when I retired, I went to work for them.
I've used Royal Purple in my Z' and though it seem to work ok, The cold shifting was not right, Between first and second it was very notchy. The car just wouldn't shift smoothly until it was fully warmed up. I switched to GM Synchromesh Transmission oil and the notchy shifting went away. Smooth shifting when cold, Absolutely great shifting when warm. I'm happy again.
I have used Red Line for 15 years. Put in my C6 at 1,000 miles. Red Line only uses premium ester stocks, so it has more stability at higher temperatures.
Their products work so well that when I retired, I went to work for them.
any exact model # or name i can look for ?
Originally Posted by Z06pete
I've used Royal Purple in my Z' and though it seem to work ok, The cold shifting was not right, Between first and second it was very notchy. The car just wouldn't shift smoothly until it was fully warmed up. I switched to GM Synchromesh Transmission oil and the notchy shifting went away. Smooth shifting when cold, Absolutely great shifting when warm. I'm happy again.
Do you know if they sell Synchromesh at other place than Chevrolet dealers like in normal big chain stores ?
edit: I read that the PENNZOIL® SYNCHROMESH MANUAL TRANSMISSION FLUID is the same as the GM Synchromesh, just rebranded.
I changed out mine out at 35K with Amsoil ATD1G. It was recommended to me by the Amsoil techs after I explained I was having the typical 2nd gear synchro issue when the car was cold. After changing, the shift into 2nd was better got better but still not quite as smooth as the rest of the gears. Come to find out, GM uses a cheaper synchro for 2nd so it tends to be a little "Notchey".
I put in Mobil One Synthetic ATF. It is a Dexron III replacement. GM does not recommend a Dexron VI replacement in our manual transmissions... only in the automatics.
^^^Reminded me, years ago, one young engineer in our group used to say he never change transmission or differential lube -not only he was well liked- he was bright and he learned fast.
I put in Mobil One Synthetic ATF. It is a Dexron III replacement. GM does not recommend a Dexron VI replacement in our manual transmissions... only in the automatics.
I can't recall which Mobil 1 I had put in, but it was a couple years ago. The shop I use likes either GM or Mobil 1, so that's what I went with.
The Corvette Tremec manual transmissions spec out an Dex III ATF, not a manual synchromesh fluid. In general the synchromesh fluids are going to have a viscosity about 30% higher than that of a Dex III ATF. This is the proper AMSOIL fluid for the Corvette Tremec manuals, which I have been using in my 02 Z06 at the track for about 7 years now without failure: AMSOIL Torque-Drive Synthetic Automatic Transmission Fluid (Product Code ATD1G)
More than happy to get AMSOIL products for forum members at dealer wholesale pricing, about 25% below retail, via the AMSOIL Preferred Customer Program. Drop me a PM if interested.
Manual transmission fluid.
