3650 Trans Fluid Talk.

[QuickShift281]

Im sure that there is probably a thread about this floating somewhere but through a quick scan I couldnt find one. I previously had a 2001 GT and never had any irregular trans noise even after nearly 200k miles. Fast forward to my 2005 GT, trans is a little louder than I have experienced. Not enough noise to concern me about being broken, but loud enough for me to make a thread.

The question is, what fluid are you guys running in your 3650? Is there anything you all would recommend to quiet a little bit of input shaft noise? Every trans I have ever had/changed fluid in I just used the Ford recommended Motorcraft Fluid.

Thanks for the input ahead of time.

 

[Mikes06GT]

I'm curious about the comments on this. My buddy on his 07 had changed to GM fluid and said was much better and also said Ford over fills. So I'm curious if anyone will confirm this or if this was just his experience .

 

[dysan]

I spoke with Tremec when I still had the 3650 in my car and they recommended GM Synchormesh type fluid. I put the Royal Purple Synchromax in mine and it worked great.

 

[skwerl]

Synchromesh. I used the Pennzoil brand available at most any corner auto parts store for about $8 per quart. Worked awesome and smoothed out the shifting as well.

 

[05gtowner]

Ford recommends mercon v, tremec recommends Mobil 1 synthetic atf. Varying reports say the syn is to slick for our blocker rings and causes them to degrade over time. I have always used a quality mercon v be it motorcraft or castrol and have over 120k on the original trans and clutch without issue. I am just going to keep using what is spec'd for it.

 

[thump_rrr]

Mobil F/M worked the best for me.
I tried Mobil 1 synthetic, Royal Purple and Penzoil and the cheaper stuff shifts better.

 

[joe_momma]

I switched to Mobil 1 synthetic ATF and it didn't make any difference in the shifting. I was pretty disappointed in the $40 I wasted on it.

 

[dark steed]

I got Amsoil from Greg here on the forum. Much slicker shifting with it

 

[rojizostang]

royal purple made no diff in mine

 

[BruceH]

Ford recommends mercon v, tremec recommends Mobil 1 synthetic atf. Varying reports say the syn is to slick for our blocker rings and causes them to degrade over time. I have always used a quality mercon v be it motorcraft or castrol and have over 120k on the original trans and clutch without issue. I am just going to keep using what is spec'd for it.

FYI Ford used to recommend Mercon until it was no longer available. Tremec told me to use Merc/Dex 3. I found a mix of RP and ATF to work quite well when I had a 3650. All RP was fine in the summer but come colder weather and the shifting was slow until the fluid warmed up.

 

[svtadam27]

If I am remembering correctly, Bob Hanlon recommended 4qts dexIII.