Anyone running Transynd or Torqdrive (Amsoil) in their 2006 Allison 6 speed? I had a concern on the fluid color of mine running Torqdrive and called Amsoil - they said that Troq-drive isn't recommended for the 6 speed Ally and only their standard ATF was - the 6 speed is a factory DexVI fluid fill and Transynd can't be used per GM.

When I recently had a "normal" high temp issue with my '07 Classic 3500 DRW, both the Chevy dealer and Allison recommended that I use Transynd. As Chevy put it, "All of our big trucks come with Transynd; it handles the heat better." Allison thought that I may already have Transynd (I don't). But it is my understanding that Dex VI and Transynd are compatible (which was confirmed to me by the Allison service manager). I know of nothing from GM that says Transynd can't be used. Where doe that come from? Incidentally, they both said they were familiar with my issue and also recommended the deep pan and perhaps a larger cooler.

transyn in my 6 speed now for 8000 miles , no issues !

Since my above post, I've done still more reading and searching. Frankly, I don't know if Transynd is appropriate for the '06 and newer Allison 1000. What I posted concerning the dealer's observation and Allison's is exactly what I was told. But I don't really know if they were up to date on their info or were referring to the earlier Dex III transmissions. Anyone clarify this? And I can't find an online Allison recommendation for Transynd in the 1000s. The best I can find (direct from Allison) has been posted elsewhere in DP, but I'll repeat it here:

"Allison Transmission recommends that all customers use TranSynd™ or TES 295 equivalent fluids to extend drain
intervals and enhance transmission performance and durability in all operating environments. Customers may continue to
choose from a wide variety of Allison-approved fluids. General Motors no longer licenses DEXRON®-III fluids effective
January 1, 2007. DEXRON®-VI fluids may be used in the 1000 and 2000 Product Families transmissions beginning with
S/N 6310670488 and 6320784373. DEXRON®-VI fluids may be used with the 3000 and 4000 Product Families
transmissions beginning with serial numbers 6510717075 and 6610220990. DEXRON®-VI shall NOT be used in Allison
500, 600, or 700 Series transmissions (AT, MT, HT/V/CLT products)."

Transynd here without any problems.

I had the dealer flush and put in Transyndat 32,000 miles and now have 67,000 with no problems. The color looks good, I'm getting ready to do it again.
The reason I went to Transynd is I tow a heavy travel trailer in over 100 weather here in California, I wanted the best protection possible.

Try to adjust the trans fluid level to the middle of the high and low mark at normal operating temp. The older models run cooler at that level. Hope this helps...