Tranny Fluid of choice

montecarlofast

740 ftlb Rocket Couch
Joined
Oct 23, 2006
Kind of a basic question, but for a stock freshly rebuilt 200 4R what trans fluid have you guys had the most success with?
 
Good Info above^^^.
Do a search in Trans section, it's been asked (many) times. Info on everything from Type F, DexIII, DexVI, Tractor Hyd. fluid etc...
 
It was rebuilt before i got the car. when I pulled the motor and trans the fluid looked clean. (i had been told that the car sat for 10 years without running because the bill at the trans shop wasn't ever paid) So i kinda gotta guess. Ill do a search in here though.
 
FWIW Lonnie told me to use Type F and that the newer formula dex is designed for smooth shifts...smooth shifts = slip
 
Went with Dex 6 with my recently rebuilt trans. Only have about 50 miles on it so far. Apart now for some paint work.
 
LOL..Interesting....Guess he has changed what to use since last year, i'll be calling him to get the skinny.
 
LOL..Interesting....Guess he has changed what to use since last year, i'll be calling him to get the skinny.

Yes, a year or so we were just starting to use DEX VI, so now we have more experience with it. :cool:

Lonnie, like myself and others, have found that DEX VI has a higher temp rating like most all synthetic ATF, and does not break down quickly as will Type F and DEX III.

We have found it will last 3-5 times as long, so that also makes it much more cost effective as well! :)
 
It seems like there is a lot of debate over Dex VI among tranny builders. Some builders who specialize in high horsepower newer GM trannies that originally came with Dex VI can't stand the stuff and that even in stock vehicles it has shown problems in early 06 trannies that were originally designed for Dex III but, got Dex VI when GM did the changeover. Then there are some builders who build older GM trannies that originally used Dex III are saying use Dex VI. Builders who build Allisons for 500+hp/1000+#s diesel powered pickups claim Dex VI is brutal on clutches and seals and they'll only use synthetics. It's definitely confusing especially when there are still other builders who say use type F. Whether it's relevant or not, power steering pumps that run fine on Dex III will fail on Dex VI.
 
i think it all comes down to what your trans builder wants you to run. He will be the one fixing it under warranty if things go south.
 
if you're running the 200 4r than it's a gm trans. dex is for gm. if you use type f yes you gain grip because that stuff is like motor oil thick almost but i kills your clutches. if you want to keep the life of your trans by using the right fluids that were meant for that trans but you want the good crisp firm shifts of type f than look into getting B&M Trickshift. even in hawaii it's not that expensive. it's almost $7 fer quart. just rebuilt my th350
 
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