4 speed transmition oil

DJVCUDA said

my dad bought a 1970 challenger new in late '69 - it came with AFT - we rebuilt the tranny when it hit 112,000 miles ( hard miles ) and guess what went back in? ATF.

we didnt need any syncros, or gears either... so if the tranny has been taken care of the atf will not wear any more/ less then any other fluid.

I'd also use Jamie Passions formula - he would definately know what he is doing -

here is how the car was shifted it's whole life....
hell the car even towed a camper all over it's the 70's..

Click to expand...

Sorry, " a lot of wear" means "noticable wear". I can always tell if a trans had ATF or 90 wt gear oil after a lot of miles. Most wear is in the synchro splines, shift plates(shoes), roller bearings and countershaft(inside the coutershaft gear cluster). These are usually replaced, and will bring most 4 speeds to like new performance, barring any abnormal damage. I know Mopar used ATF from the factory. It was the first thing I replaced when I got any four speed or OD trans. I'm talking street performance and longevity. I'll give up a fraction of a second in the quarter mile or a fraction of a mpg. Racing is a whole different use, as OUTLAW described.