ok to use synthetic tranny fluid in a 4t60-e?

[Tim's Buick]

I need to flush the old junk out and change the filter. The fluid im using is fod dextron 6 and is a full synthetic. Ok to use in my 93?

[ron350]

Some transmissions will work fine on just about any fluid but a few will only work on the factory fill.
People that have never had any trouble switching fluids love argue about this.

My 96 Regal will only work properly with DexIII clone fluid. I tried switching to synthetic Vavoline Maxlife and the transmission started whining and having sloppy shifts after one week. I had to do a couple drain and fills with Castrol Dex/Merc to get things back to normal. I had to pick an aftermarket fluid because AC Delco no longer sells Dex III.

After going through this I will only use factory fill transmission fluid from now own.

[nos4blood70]

Apparently Dex VI is backwards compatible.

[SSEiMan01]

Is it backwards compatible. It should work in a 4T60. Our lookup at work dictates Dex 6 for about every GM trans it lists. With the exception of old old transmissions like TH350/400 etc. I haven't looked up a 4T60 but I'd imagine it would be fine.

[RJolly87]

The only concern is the additional detergents in synthetic. If your tranny is being held together by crud, then when the crud gets broke loose, your tranny will soon follow.

[Tim's Buick]

Im pretty sure the transmission is good. Its already the second one for this car. No slippage and shifts the very best. The fluid is red, but looks a bit old and darkish. Last one went bad at 400, 000 kms and that was because trans fluid and antifreeze don't mix.

I am getting ready to install a tcc solonoid and basically the tranny has to be dropped for this job. That is why I asked.