I was told to get ATF, but all autozone had was DEXRON-III MERCON, which is safer/better?

 

GM recommends an ATF with dexron-mercon, so I'd go with one using those 2 in it. Better yet, synthetic.

Then again, it is very possible that I am misunderstanding your question.

-Mindgame

 

ATF= DEXRON-III MERCON

ATF= Automatic Transmission Fluid

 

Yeah, i was gonna say.. i'm pretty sure they are the same thing....

 

I talked to my dad just now and he said all ATF stood for was automatic trans fluid.

And from what ive heard, synthetic is evil on our trannys

 

True that! i talked to 3 seprate transmission builders. All said DO NOT put synth in our transmissions.

 

Interesting....

I've used nothing but synthetics in my GM and Chrysler automatics over the past few years without problems. Can't say I 've had any experience with the 4L60 though... maybe it likes higher temperatures.....
I do use it in my T56 and can't make negative comments there either.

-Mindgame

 

I used Castrol syntethic in my six speed a few years ago and after about 6 months it became hard to shift and I heard grinding sounds coming out of it when I let the clutch go.

At the same time, I put the same oil in my wifes automatic maxima and that tranny crapped out a year later.

I will never use synthetic transmission oil again. Stay clear of it.

PS. I don't think you can find Castrol syntethic transmission oil anymore either.

 

no syntec

use fords ATF, its the best one out there. thats comeing from a GM 4L60E powertrain r&d engineer whos job is to blow up transmissions

 

Maybe the problem was you were using oil, should have been using ATF..