30th clone

What is the best transmission fluid to use??I have valvoline dextron 2 atf in it right now..I had royal purpal in my last tranny an did not like it made it very notchie

BES Stroked Nova

iTrader: (24)

I like amsoil, made my tranny go from notchy, to smooth as silk...

cputech

There is "No Best"...it's all about what you can afford and what you feel works for your particular application.

calhoon

iTrader: (6)

Yes there is a best. Its what the manufacturer says it should have. Save money on "mystry" oils that are bigon $$ but short on long-term delivery ( do they have a warranty?) . Stick with dexIII ATF and save your $$ for more worth while mods.

jcws6

iTrader: (1)

Any synthetic is always a good call.

MikeLSS1

calhoon what about the dexIV atf is that a good call? i can swear i've read that somewhere about it having a lower boiling point.

jcws6

iTrader: (1)

"Dexron" is GM's proprietary way of "versioning" their transmission fluids. DexIV came out in '05 and is supposed to be backwards compatible with all DexIII transmissions. The big change is: "The specification (GMN 10060) defines both a performance level and specific additives that provide improved shift feel, friction durability and oxidative stability compared to earlier specified fluids."

Apparently, something didn't work out with this fluid, so GM re-released a DexIII-based fluid specifically for manuals, under part number 88861800. I don't think boiling points & other specs were ever publicly released for Dexron fluids (proprietary, etc.), so there you go.

Picking "the best" transmission fluid can always turn into a science lesson, just as with any auto fluid. I still say pick a decent synthetic & be done with it. Amsoil Synthetic ATF is a bit pricey, but it's the one I've seen recommended the most for these transmissions.