trany fluid synthetic or not

[Dale Rd Digger]

starting out with new rebuilt tranny and torque conv. TCI street shift kit. Is it worth spending the money to go synthetic fluid. Does it run cooler, longer life or just what is the pay off for using synthetic?

[Bo Duke]

I've always read that it does make a pretty good dif, I read in a 4 wheeler magazine they changed all the fluid in the trans engine, t case, and rear ends all to synthetic and they actually gained a few hp....

[Dale Rd Digger]

thats what i was looking for. thank you very much.

[Disturban]

Ditto for new motors and tranny's but I also heard if you switch to synthetic's on higher mileage vehicles they can cause seals to leak...but if I was to install a new motor and transmission I would run it myself. For now I will stick with dino oil!   

[Dale Rd Digger]

thanks disturban.exactly what we were thinking , now or never.

[Bo Duke]

I've always heard from engine builders to always use regular oil to break in an engine then go to syn.

[Disturban]

I've always heard from engine builders to always use regular oil to break in an engine then go to syn.

This is true to seat the rings...I would switch to synthetic after about 1000 miles. I dont know if you would need to do this for a transmission though as there is nothing that needs to be seated. Might want to investigate this a little bit before running synthetic right off the bat!

[Dale Rd Digger]

no drain for torque converter?

[Disturban]

no drain for torque converter?

There is a big hole in it...ya have to tip it sideways

[Dale Rd Digger]

oh yeah

[Disturban]

I dont know of anyway to drain it except taking it out and dumping it out. Might want to see if the synthetic is compatible with regular ATF and if it is just drain the trans and replace with the synthetic and dont worry about the little bit left in the converter...if you are do it twice!

[jimmydean]

I have been running AMSOIL for 20 years. In my quads (100-1 ratio) lawn equipment. You name it, I run that oil in it.  I changed the trans in my dd over to it two years ago. It runs 20deg cooler.  And, no it will not ruin your seals in older vehicals.  Just my experience and two cents

[Squirell]

i run synthetic in my DD with 193000 and switched about ten thousand ago and it gets better gas mileage and dont leak any oil

[Dale Rd Digger]

the only thing that i was told before this post is that syn is not compatable with reg. But nobody had much exp. with it in trannys. I really wondered about temp. differance. if temp lowers then most likely there is deffinetly less friction, which means less wear over time. Thanks guys for all your input .my son has 430.00 into this tranny ,torq conv . we just wanted to start it out right. Any advice is appreciated.

[jimmydean]

You can mix regular oil with amsoil, but if you do that it takes away from some of the properties in the synthetic. You are correct with the lower temp. All syn oils run cooler. some are better then others. I run ams because of the extended drain intervials. with the motor oil i go 25,000 before i change it. the trans is good for 150,000.    and the diff fluid is good for 250,000.      My old truck had 275,000 when i got rid of it and it never dropped a spot of oil and i never did any work to any of the internal parts. The motor and trans still ran strong.   Go synthetic and you will never look back!!   

[mudbrat71]

syth is good that is all the newer vetts and high dollar cars run.  butt i would not go 150.000 with out servicing it