cavediver

I'm the original owner of a 2007 Mustang GT with the TR-3650 manual 5-speed transmission and it currently has 16,000 miles on it. I have a Hurst short throw shifter and it always functioned just fine. I've never had any grinding, no missed shifts and no rattles or other noises. At 15,000 miles I decide to change the transmission fluid and went with the owners manual spec which calls for Mercon V. In my case I used the Castrol brand. With the change I noticed a very slight improvement in the shifting effort. That got me thinking about other fluid options that could improve it even more. Keep in mind that it wasn't shifting bad but it definitely got smoother with the Castrol Mercon V. I did the usual internet search and found the everyone had a favorite fluid that either made it shift like butter or one that they were sure would ruin the transmission.

I decided to call Tremec and talked to one of of their tech people. I asked a simple question: "What fluid does Tremec recommend for function, reliability and performance in the TR-3650?". The guy I spoke to said that they recommend Mobil 1 Full Synthetic ATF as the best choice for the TR-3650. I went to Advance Auto and bought 4 quarts of it for $9.99 each and changed it out last weekend. BTW, I put in exactly 3.2 quarts.

The results? I got a noticeable improvement in the shifting effort of the transmission. It is much less "notchy" and it is much smoother overall. I couldn't be happier with the results. It's the best $40.00 I ever spent on the car.

If you happen to swear by RP, Amsoil, Syncromesh or whatever, that's cool and there is no need to jump on here and wave that flag. I'm only telling you of my own personal experience with Mobil 1 Full Synthetic ATF that gave me a very positive result.

http://www.mobiloil.com/USA-English/...etic_ATF.aspx#

hammeron

great info, thanks cavediver!

moosestang

Did you notice a reduction in the temperature of the hurst chrome shifter? Mine used to get to hot to touch before switching to a synthetic MTF. Now it takes hours of driving just to get warm.

I'm talking a 15 mile drive to work and it would be hot, hot.

cavediver

Mine would get warm but no more so than my 67 390GT 4-speed or my 85 GT 5-speed. I'll see how it gets now with the Mobil 1 synthetic.

moosestang

Mine was down right uncomfortable with the stock oil in it. My stock fill could have been low from the factory though.

Diabolical!

I noticed the same as moose after switching to Royal Purple's sychromesh. OP, I think you made a good choice with the Mobil 1. I was on the fence about that or the RP when I did mine. I don't think you can go wrong either way.

pascal

I thought Tremec used GM Synchromesh in their transmission?
Anyway, glad the ATF Mobil1 worked great for you OP...