If I do not want to use a synthetic fluid or Stansdyn, just a standard Dex III, what brand should I use? Are they all the same at that point?

I have read many posts but I can't really find any with names of specific brands. Is the AAMCO Dex III good enough?

I understand from the posts that Stansdyn seems to be the choice of many, but in case it is not available at the time.

If there are other posts with this info, I'm sorry for the repeat.

Radvans,

Do you mean Transynd, it is a synthetic fluid developed by Castrol specifically for Allison. You'll probably have to go to an Allison tranny shop to get it. As far as other fluids, it's your choice, anything labeled as a dexron III will meet specs. I'm a big believer in synthetics, but it's your truck.

I've used Havoline Dex III for years with good success. It seems to hold the clutches well and not burn as easily as other brands I've used.

I've seen the AAMCO Dex III you're talking about, & in small print on the back of the bottle, it says it's made by Exxon Mobil, so you shouldn't have any worries about it's quality.

I had a GM diesel rep. (one of the techs on the Duramax from Detroit) tell me last week if you have an Allison shop replace the trans fluid that they will extend the trans warranty to a 100K. I have not been to an Allison shop yet but do intend to see if this is true.

Thought it was covered to 100K?

My friend that has a trans shop says that the factory fluid in the Allison is synthetic, and not to change it unless it has lots of miles or is burned.

The factory fluid is synthetic but not Transynd. Is the trans covered for 100K from GM ?? I thought only 36K.

I had a GM diesel rep. (one of the techs on the Duramax from Detroit) tell me last week if you have an Allison shop replace the trans fluid that they will extend the trans warranty to a 100K. I have not been to an Allison shop yet but do intend to see if this is true.
After reading this, I called an Allison dealer. He said all work on Alli's in GM pickups is handled through the dealer. So I called the dealer, and they are checking to find out about extending warranty w/oil change. Stay tuned.

Warranty on allison is 36K duramax is 100K

Marcdeluca and Aegis, (Anyone)

Are you 2 certain that the factory installed, O.E.M. fluid is "Synthetic"?? All this time I thought it was just a regular Dexron equivalent.
Anyone confirm this? Thanks.

My friend with the trans shop is a subscriber to a company that does research on transmissions. In fact, the company is Transgo, and they have engineers that study how to improve durability. They told him that the Alli fluid is synthetic. I can't prove it, but if anyone would know, they should.

Thanks, Marc. I'd sure like to get a confirmation of if it is and what specific brand it is. Maybe MikeL would know? Mike, you out there?

A question for the Amsoil users, which is preferable, Synthetic Universal ATF or the Torque-Drive Transynd replacement? Retail price is about the same but I can get the Amsoil product at dealer prices.
Thanks
Hutch

I used some Universal and my trans immediately developed a small TCC lockup shudder. I completely changed the fluid and used Torque Drive and fixed it. My experience is only use the Torque Drive. It is supposed to be exactly like Transynd.

I have seen very few Allys come through my shop with synthetic fluid. I have talked to Transgo about this. Now, if you bought an extended warranty you might have TranSynd in your Ally because a lot of the warranty companys make it mandatory that the dealer change out the fluid. Come to think of it, only John Hamlins (DPS) big dually had TranSynd in it and I don't know the circumstances why. Maybe John can enlighten us.
mike

What is this? It says it's specifically designed for GM vehicles. I can get a case at Costco for about $12.

Schaeffer's 204SAT trans fluid now has Allison under its recommended applications. I was watching this for some time and after Schaeffer's switched the formula of their trans fluid, Allison was listed. I had not seen Allison mentioned at all prior to the refomulation.

IIRC Allison does warranty medium duty trucks that use their 1000 series automatics for 100k, but GM only warrants them for 36k in our light duty trucks. Though practically the same, they appear to have different warranties. Go figure! :o: I visited an Allison dealer, they will change your fluid, but they have nothing to do with your warranty period from GM. :)

Back to the original question, I wonder why anyone would want to use anything other than Transynd or synthetic Dexron III? There is plenty of intel on this site and testaments to how well they perform, especially for heavy applications. Just wondering? JJ :)

JJ,

What is the cost difference between regular and synthetic? That may be a big difference.

Somewhere in one of the forums I have been, someone said that if your Allison has synthetic ATF from the factory, it will have a tag of some sort on the ATF dipstick. Otherwise, it is Dextron III. I will try to locate the source.