synthetic trans fluid

Ozlander wrote:

Charlie D. wrote:
Although Dexron VI is a tremendous fluid it is a synthetic blend.

Not if you use Valvoline DEXRON-VI Full-Synthetic Automatic Transmission Fluid.

You are correct and I knew about Valvoline. A number of people have made blanket statements that Dexron VI is synthetic which is not the case. When researching what synthetic to use in my previous truck I found the Transynd which is made by Castrol and IIRC, was the only true ATF synthetic at that time, Along with Valvoline there may be other brands but I have not researched it.

Neither Amsoil nor Royal Purple are on the Allison approval list. GM may approve them.

I just "bumped" the following from the Class A forum: "Let Me Know if You Have Allison Transmission Fluid Questions"

I switched my '04 4L80E over to Decron VI. I used the drain + filter replacement, fill, drive, drain, and fill method. I have noticed towing temps are about 15 degrees cooler. Also, shifts through all gears feel much firmer. Each gear hits with very little lag.

Yep, straight AMSOIL for me in trans, transfer case, diffs, and engine.

Charlie D. wrote:
Although Dexron VI is a tremendous fluid it is a synthetic blend.

Not if you use Valvoline DEXRON-VI Full-Synthetic Automatic Transmission Fluid.

Although Dexron VI is a tremendous fluid it is a synthetic blend. According to the inventor of Transynd, a double drain and fill of the pan will give you all the protection you need.

Do a fluid "exchange" it is real easy and it gets ALL of the old fluid out.

Allison says flush will harm internal seals.

Paul Clancy wrote:

mtofell1 wrote:

AYRTIME wrote:
I've switched to Transynd in my Allison. That's what we run in commercial highway coaches/tour buses. Runs cooler, smoother shifts, longer drain intervals, etc.

How do you do the switch without leaving some of the older stuff behind? Or, is it okay to leave some and blend them?

Takes 2 drain (drive some) fills to be considered a change out. Do NOT flush Allison. Dex6 is mix compatible with transynd.

Why do Not flush Allison?

mtofell1 wrote:

AYRTIME wrote:
I've switched to Transynd in my Allison. That's what we run in commercial highway coaches/tour buses. Runs cooler, smoother shifts, longer drain intervals, etc.

How do you do the switch without leaving some of the older stuff behind? Or, is it okay to leave some and blend them?

Takes 2 drain (drive some) fills to be considered a change out. Do NOT flush Allison. Dex6 is mix compatible with transynd.

Synthetic for me from front to back in everything we own