transmision oil

[gandulf2003]

hello again

what is the best tranny oil!!! and why plz

[Trevor]

pretty sure if you got a 4l60e you need DEX IV. I know of castrol and supertech at walmart that makes it. Ive also heard that tranny fluid has to be so exact when it comes to the ingredients or additives (not sure what you call what its made of) that you cant go wrong with any brand.

[farmtruc]

We use Pennzoil or whatever housebrand the auto store has, as long as it's DexIV, DexVI covers most of the trucks too.
Never had an issue with just plain old convential oil. if you call around, most transmission shops will recommend that.

I think it's more important to keep the trans running at a cool temp and change the oil often. I change mine about every 15-20K miles and it always looks great.

I'm no expert on oils, but this is what works for us.

[RUFFNECK]

Yeah tranny fluid is more for pressure than lubrication. Keeping the fluid clean and cool is the best thing to do than to look for higher dollar brands when the same thing is required.

[gandulf2003]

thanks all, i live in a very hot place last two weeks almost 56C , and the guy who rebuilt my tranny said that he have only the AC-Delco oil!!!!!! i dont know wht i hate this kind of oil!!!! and by the way my tranny is 4L80E on a classic silverado 2500hd

[timber74wolf]

What is the difference in the Dex IV and VI? I think I read the Dex VI gives results like using the Type F back in the days. Lets the tranny grab harder with limited slipage... Correct?