Stone River Products Castrol TranSynd 668 Allison 2021 Updated SPEC 1 GALLON ONLY BY DOXA WORLDWIDE

Great fluid. Chevy shifting so much better now.

Top notch fluid!! Thanks

Started using Tes fluids 8 years ago in my 2005 duramax. Trans developed a shudder and jerking motion going downhill in cruise control. Called Allison tech support. Was told Dex VI wasn't good enough to protect 1000 series trans internals and seals. Changed to Tes 295 and all trans symptoms disappeared. Did forward system flush to get all Dex VI out of the system. 4 gal. Now I'm using 668. 322,000 mi and the trans shifts like new. Can be used in NP and Magna 263 and 261 transfer cases . I do a pan drain every 2 years and canister filter every 12 mo. The cleaner the fluid the cooler it runs.

Case of three 1 gallon containers arrived with no spills or issues mentioned in other reviews. Did an Allison 1000 transmission fluid and filter (x2) change on my 2017 Chevy Silverado 2500HD Duramax. I also changed out my transmission cooler lines at the same time to upgrade my cooling system. The allison 1000 change usually takes about 10 quarts of fluid. With the additional line replacements, I need a couple extra quarts to re-fill so this package worked perfect. Was able to put all three jugs in and it put the level right where it needs to be. Also saved a few bucks ordering it through Amazon versus my local auto parts stores.

TranSynd 668 is one of the best transmission fluids available on the market currently. Developed specifically to meet rigorous Allison specifications for heavy-duty working trucks. Also works in GM transmissions like 4L80 and 6L90 and has better performance than standard ACDelco or GM Dexron VI or III fluids. OK to mix with Dex until the next fluid change. TranSynd is considered a more versatile premium synthetic option that meets a wider range of specifications and has a higher shear resistance. It can withstand more shearing forces without breaking down, making it a better choice for applications requiring extreme durability. Been running it in all of my GM and Allison transmissions for many years. Recommended.

Shipped and delivered quickly. Bought this for my 03 Duramax with the Allison 1000 5-speed. I heard this was the best fluid for an Allison. As of right now and the past few thousand miles it has been perfect. Time will be the true tester.

This is the only transmission fluid I will use on my truck period !!

This is the fluid needed for your Allison transmission

I’m giving it 5 stars because it’s fully synthetic, I’m only expecting the best, the trailer will be the test

Everything was fine as described

My chevy is 7 years young now and I swap out the external filter yearly and change out the oil every 2 years. Never ever had a problem using this oil. And I only use Alison filters BTW

Excellent product, good delivery.

Arrived on time and as ordered. why after purchasing items that they are offered at a lower price?