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

Great fluid. Chevy shifting so much better now.

Great fluid

Fast delivery

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.

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.

Was usable with no bad effects in 2002 GMC seirra2500HD ALLISON TRANSMISSION/Duramax6.6. No wrenches on transmission or motor in 25 years. Change fluids in power steering, radiator, autotran, and motor. Change power steering and serpentine belt every 10 years. BEFORE STARTING -twist key ONLY to on- USE THE LITTLE PENCIL ERASURE SHAPED BUTTON LEFT CORNER OF DASH PRESSING 3-4 times till BELL SOUNDS and lights go out and EXTRA POWER DIVERTS TO STARTER MOTOR FOR FASTER SPINS. I’m still on first motor starter because of this. NOW TWIST KEY TO START POSITION AND RELEASE NOW AGAIN button pressing for audible BELL and LIGHTS COME back on.

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Great product. Thank you

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?