transmission fluid... what type?

[elvis50138]

Been forever since I had to add any fluid. What kind should I add to a 700r4? Just plain old automatic transmission fluid ATF or does anyone recommend one brand and/or type over the other?

[ed455]

Most rebuilders say type F, factory says dextron.

I always use type F on rebuilt/modified trannies.

[qksilver]

The F type will act like the racing fuild. Dextron fuild is made to slip more than the F type. So the F type will work better.......use a name brand not an off brand

[cableguy0]

DO NOT add type f to a trans that has been running dextron since new.you will end the life of that transmission. type f expands the seals and will deteriorate the clutches.run dextron like what is reccomended by gm.

[ed455]

Yep, that's why I said rebuilt/modified. With a factory built tranny, run what the factory put in it. Once you rebuild it, then change to type F.

[Green Machine]

I will say DO NOT run type F in a GM transmission. Yes the type F is a higher friction fluid and it will make the clutches hold better. BUT - the bushings and thrust washers are not designed for a more aggresive fluild. You will have more wear and a shorter trans life on the internals. I would rather have a little softer shift and have the trans live longer, but it is your call.

[ed455]

Originally Posted by Green Machine

I will say DO NOT run type F in a GM transmission. Yes the type F is a higher friction fluid and it will make the clutches hold better. BUT - the bushings and thrust washers are not designed for a more aggresive fluild. You will have more wear and a shorter trans life on the internals. I would rather have a little softer shift and have the trans live longer, but it is your call.

I have 138,000 miles on a 4L60 since it's rebuild and have run type F in it since then and it still shifts well and seems as good as the day it was rebuilt. Only got 68,000 miles out of it from the time it was new before rebuild. We used Detron when it was new. EVERY, and I mean EVERY tranny rebuilder I have ever dealt with spec type F in the trannies they build. Most give 50,000+ mile warrantees so it's to their benefit to get you to run what will give the best longevity.

I'm not trying to get into a pissing match but your statement disputes everything I have evr heard from tranny guys.

[cableguy0]

im not intending to start a pissing match first off but every tranny guy i know wouldnt use type f in anything and in fact will run dextron in old ford trannies after they are rebuilt.I'm speaking of guys who build a lot of full out race units handling 1000+hp as well as dead stock units.i have always been told that type f wrecks the bushings and seals in just about anything

[elvis50138]

Thanks for the responses I have had the tranny rebuilt so I reckon I better call them and see what they use and go with that it sounds like. Thanks again.

[Green Machine]

No pissing match intended, just speaking from my experience. I used to rebuild trannys at transmision shop in Mesa Arizona for a living, now that was a while back, A&B transmission, Larry ? was the owner, those guys still around ?? Anyway, I rebuild my own turbo 350 there, and yes I put type F in it, worked great until I took a 1000 mile trip with it, and wiped out the bushing between the front drum and the pump. Now I had even installed a wider heavy duty bushing in there during the rebuild. Turbo 350's like to wear out there anyway, but with a fresh overhaul and less than 5000 miles on the trans, I think the long hot extended drive and the type F took out that bushing. After rebuilding it again and using Dexon, it never had any more problems. Just never trusted running type F again in a GM tranny. I've rebuild many since then, and have always just run what it is "supposed" to have.

[fastwillie 696969]

i use royal purple no problems

[Nolowrider]

I have heard good things about the Amsoil ATF, supposed to lower the temp by 15*. Thinking of using it on my next fluid change.