Tremec 3650 Fluid

Discussion in '2005 - 2009 Specific Tech' started by kevlar911, Dec 1, 2004.

  1. Just wondering what fluid Ford uses in the Tremec 3650 manual tranny on the '05 and if you would benefit at all from dumping it and putting in GM Synchromesh, which is the preferred fluid for Tremec transmissions. I put Synchromesh in my '95 with the T-5 tranny and noticed smoother shifts right away.

  2. check this out
  3. Motorcraft MERCON ATF
    P/N XT-2-QDX
  4. Stick with ATF, the 3650 was designed with it's properties in mind.
  5. tryed the dextron III in my 03 3650 made no difference tryed a mix or redline d4atf and dextron III made shift feel less consistant now i am going to try the new gm synchromesh friction modifyed ill let you know how that works out.
  6. "GM Synchromesh fluid it is not recommended
    for use in the 3650 model because the High Sulfer content
    is harmful to the Carbon Fiber/Paper Synchro Blocker"

    you should put Synchromesh fluid in a T5/TKO, don't use it with a 3650... Tremec recommend against it, stick with any ATF Dexron III of your choice.
  7. The t-5 has the same Carbon FIber/Paper synchro blocker rings for 1-4 gear. So that's a No-no to synchromesh in the T-5 as well even though i know tons of guys who will say otherwise.

    The only Tremec trans that requires synchromesh is the 3550/TKO versions. Everything else is ATF/D3
  8. sorry, i meant to say 3550 instead of T5
  9. Mobil 1 ATF!
  10. Ford uses 3.0 L of the XT-2-QDX (non-synthetic) in the '05 GT, 3.7 L of the XT-2-QM (full synthetic) in the '04's and 3.8 L of the XT-2-QM (full synthetic) in the '03's.

    Like mach1dsg said the GM Synchromesh fluid it is not recommended
    for use in the 3650 because of the Carbon Fiber/Paper Synchro Blocker. I talked to a Tremec Engineer and he said the GM fluid was ok in the T-45 but to only use a Dexron III fluid in my '03, which the XT-2-QDX Ford recommends for the 05 is.

    The TSB from Ford that fixes the transmission problems of the 3650 also states to use the XT-2-QDX. The TSB also recommends the quantity to be 3.0 L like the '05 requires.
  11. Great post.. Points well taken however i tried them all and when cold they do nothing for shifting performance in my 03.. it doesnt grind at all just very poor shift feel. i shift first 2 third when cold i double clutch when cold i cant stand it im putting the new gm syncromesh friction modifyed in it this winter and giving it a shot. supposidly it is produced by texaco and they claim that the sulfer content is extreamly low and non corosive to carbon fiber/paper syncros however i cannot get them to put it in writing. :rolleyes:
  12. That problem is a design flaw in the transmission. There is a TSB for it which replaces the 1st and 2nd gears and synchros.

    I wish it was as easy as a fluid change to fix the T-3650 clunk, but the synchro design is very poor. The synchos don't have enough friction to slow the gears and match speed when cold. Supposedly the TSB is a redesign of the assembly, but i've heard of people having probs with that as well.
  13. I've had TSB done on my Stang and I found out that intelligent tranny shop actually filled fluid level back to the top. I dropped fluid and put in synthetic merkron ATF (at the correct level), should I have used regular merkron ATF and not synthetic? I noticed an earlier post said that pre '05, synthetic is recommended (mine is an 01)? I thought tremec said no synthetic fluid????