Tremec Trans and Red Line D4 ATF

[Silver281GT]

Been quite a debate, lately. Tremec recommends GM Synchromesh, DexronIII/Mercon V, and Mobil 1 ATF, and claims that Red Line D4 ATF and other synthetics will actually destroy the blocker adhesives in most of their transmissions (T3650).

Red Line claims there is absolutely no proof of D4 causing problems, and states that there are thousands of Mustangs equiped with T3650 and no problems have been reported to Red line...

I am looking for a good fluid to put in my transmission (2003 Mustang GT w/ T3650 5 speed).
I have been using GM Synchromesh, but I am tempted to go all synthetic for the price I pay. Although GM Synchromesh says, on the bottle, "will not break down," I am more confident in Red Line's ability to protect (PE Basestock).

Can we distill any truth from these two completely opposite claims?

 

[unDummy]

I've heard the rumour. But, I haven't seen the proof.

Synchromesh is thicker then ATF. If no problems, you could consider the Redline MTL, besides the D4 ATF.

Royal Purple Synchromax or ATF, Amsoil MTF and ATFs, Torco's ATF or MTF, SpecialtyForumlations ATF MTFGlide or SynchroGlide, are some other options.

 

[Silver281GT]

Thanks for your response...
No proof that the synthetics case problems, but that doesn't help my mind rest...

Is there any way we can try to get to the bottom of this debate between Tremec and Red Line?

Be nice to dispell a myth...

 

[chucky2]

Silver281GT- The same debate has been had (and will continue to be had) about T-56's found in F-body's from 98-00. The Which T-56 Fluid is a long read, however it may be worth the time (I know it's not the same tranny though):

Which T56 fluid?

Ending the speculation: Blocker rings, who's had them fail?

I'll leave you to read and draw your own conclusions...

Chuck

 

[neo3]

I've got a 00 Camaro, been using synthetic ATF for about the last 20K miles with no problems (other than the notchiness it had from day 1). Bought new, now at 24K miles. Used D4/ATF for maybe 12K miles, now using Royal Purple Synchromax (or whatever it's called). The RP stuff actually seems to be the best by a slight (maybe imaginary) margin so far. It works best when it's _completely_ warmed up, like 20+ minutes of driving at least. This makes me think that any thicker fluid will be worse, since it works better after thinning by heat. BTW this is not in a cold climate area.

 

[gtx510]

fwiw, RP SM and RL D4ATF are almost the thickness.
www.royalpurple.com/prodsa/scmax.html
www.redlineoil.com/pdf/6.pdf

Same with SF's MTFGlide?
www.specialtyformulations.com

 

[Dominic]

I swear Ive tried many fluids
Valvoline Durablend ATF
Mobil 1 Synthetic ATF
Redline High Temp ATF
Redline D4ATF


and the best of them all was Specialty Formulations MTFGlide. My car has never shifted so well (Tremec T5). I wont ever run another fluid in it. The G5 rated gear oil in the ATF weight is the ticket to good shifting if thats what you want. Redline is only a tick better than what comes from factory. I hope you try it.