Allison's new generation fluid Transynd TES 668.
It supersedes Transynd TES 295 and is backwards compatible.
Allison video:
http://www.youtube.com/watch?v=T3XU2BEHBV8
Since Transynd is also full synthetic I will not switch until my current oil change only a month old times out. Thanks for the info on what to buy next time.
As of now not availible for purchase,if anyone finds it let us know.
Amazon.com: Castrol TranSynd 668 ALLISON 2021 UPDATED SPEC CASE OF 3 BY DOXA... (https://www.amazon.com/Castrol-TranSynd-ALLISON-UPDATED-WORLDWIDE/dp/B095SYBWQZ)
Allison Transynd Full Synthetic Transmission Fluid 1GAL 27101-CTCS PACK OF 3... (https://www.ebay.com/itm/334009188661)
Transynd Synthetic Transmission Fluid | DMAX Store (https://dmaxstore.com/products/?route=product/product&product_id=7619)
$33.99 gal. free shipping over $200 also available to pick up at a number of their locations.
Castrol TranSynd 668, 1 Gallon - Pacific Power Group (https://www.pacificpowergroup.com/product/15e2e1-transynd-668-1-gallon)
Totally agree. Stick with the change interval based on your current fluid/severe duty. Allison classifies any transmission with a retarder as "severe duty".
And, when you do change, go to the improved TES 668. I visited with Tom Johnson who helped develop Transynd TES 295 and he highly recommends going to the TES 668 at the next change interval as the additive package is even improved over the TES 295. Basically, there have been strides in chemistry over the last decade! Take advantage of them.
Perfect, I will be swapping mine this summer. Thanks for the info!
I'm still running conventional. Is there a definitive thread on how to change from conventional to synthetic?
Just do a normal drain, filter change and refill with the new fluid. Allison 3000 should take 19 quarts. Least expensive is a 5 gallon pail.
Next change interval will be based on OLD FLUID.
After that next change with the new synthetic fluid, you go to the interval based on the new fluid.
BTW, with a transmission retarder, I would not be running Dexron. The retarder classifies your transmission as "severe duty" per Allison.
Does anyone know of a test to determine if fluid is conventional or synthetic? Blackstone verified that my trans fluid is good to use, but has no test to determine type.
Best I have read you really only know if you changed it or someone before you documented it.
Great price on Transynd 668 in 5 gallon pail at Amazon prime for 166.84. I just ordered two pails.
Sounds like they may have caught up with the oil I used 4 yrs ago. Amsoil Torque Drive for Allison. Like I said at the time after I drained out Transynd and put the Amsoil product in the tyranny was much smoother and cooler.
Did 30-40k miles and never a hic cup.
John