727/904 performance tranmission fluid

[83CHARGER2.2]

Was wondering if the new ATF+4 would be a good alternative fluid to the old school thinking of high performance transmission fluids. I was changing the fluid in my dodge truck and was thinking that most of the transmission components and seals are the same between the overdrive and older 727/904 with the exception of the lock-up clutch. If the ATF+4 is a synthetic based fluid, I wonder if it would be good for HP use in a 727/904 ?? The Cummins turbo diesel guys been using this for years. I know people been using type F for years and maybe others like trick shift but would like to know how this would measure up.
Any thoughts ?

[John_Kunkel]

I'm skeptical about using +4 for performance use, it's formulated to make clutch engagement smoother which is kinda the opposite of what you want in a performance unit.

Some drag racers are successfully using the +4 in the units with over 200 psi line pressure, the increased line pressure offsets the smooth engagement characteristics of the fluid.

If you decide to use it don't worry about seal material incompatability.

[83CHARGER2.2]

I think its more for lock-up clutch engagement from what I have heard. The Turbo diesel guys been using this for 400+ RWHP trucks that weigh over 7000+ lbs and have little to no issues and seem to shift good and firm. I am just curious if its a good alternative to performance fluid with the added benifit to being mopar approved.

[John_Kunkel]

The +4 is formulated for OD lockup units, it helps prevent lockup clutch chatter and provides superior lubrication for the constantly running OD gears.

The non-lockup 727/904 doesn't suffer from clutch chatter and the planetary gears only run for a short time in 1st and 2nd gears. Type F or Dexron would be as better choice IMHO (or a 50/50 mix of both).

[RECHRGD]

SOOOOOO that must be why my new rebuilt 727 won't even chirp the tires when shifting from 1st to 2nd.  It used to do it all the time with the old tranny and that was with 60 rwhp less than it has now!!  That's what I get for listening to someone at Autozone.     Bob

[83CHARGER2.2]

I'm not so sure about that. I see Diesel guys twisting and breaking shafts, chirping the tires hard, and all with ATF+4. Has to be good for something performance oriented.