I just ordered the Transgo shift kit, vette and od billet servos, and plan to do these mods this winter. I'm also going to install a finned aluminum pan/drain plug while I have everything apart. Would it be wise to switch to synthetic trans fluid while I have it down? If I do switch, I'll probably go to an oil change place, and have the old stuff removed by their machine, then replace whatever I lose when I remove the pan/valve body for the trans mods. I've heard differeng opinions on wether to go to synthetic trans fluid, or not.

 

no, the 4L60E does not do well with synthetic

 

The only real advantage of syn fuild here is that it takes a lot more tempature to break it down than regular fuild. It is a catch 22 though because you do not really want it that hot anyway because it takes its toll on seals when you do get it that hot. Personally, I would keep the fluid cool with a aux cooler and change it regularly and not worry about the syn stuff to keep it clean internally as syn is no sub for fliud changes when fliud gets "dirty". My 2 cents anyway.

 

Thanks

 

I ran synthetic in my stock tranny. It seemed to run a bit hotter. It shifted a lot quicker than with stock fluid. Supposed to free up a few horses also. I believe it after feeling the difference in shifts between regular fluid and synthetic.

 

That is NOT correct. 78,000 miles on mine and 77,000 have been with synthetic transmission fluid.

The difference between synthetic Dexron/Mercon transmission fluid and mineral Dexron/Mercon fluid is the base stock. Not the additives.

All transmission fluids that carry the Dexron/Mercon rating are compatible with each other and use the same additive pack.

 

Ill follow what the book says on that. It just like the eaton rears, sure some people are using synth, but it specifically says DO NOT use synth. Maybe you might free up some ponies here and there, but what is it going to cost you in the long run?

 

Synthetic fluids dissipate heat better than mineral oils. So the transmission is going to run cooler not hotter.

 

That's what my trans guy told me also.

 

Ummm...