Allison Auto questions

We have a fleet of Allisons at the utility I now work for (6 years). Our units see a ton of hours, and not so many miles (bucket trucks and digger derricks). We use Allison TransSynd branded fluid in them. We service ours at 5 years/50,000 miles, whichever comes first.

 

Synthetic as stated or Mobile Delvac with the Allison spec. Often find it at Napa when needed on the road. I am sure there are others.
If it has a deep stamped steel pan there is a filter in there.
Model number would help.

 

No it is Delvac equivalent to TransSynd not 15W 40. I have been able to find that at any Napa in the middle of nowhere working on hi rail trucks. I get TransSynd from Freightliner, it is an Allison product , I thank.
All of the older models can be upgraded to this.

 

I came across that on a 6 speed Allison a long time ago. Never did get an answer so we just ran it 1/4" low on the dipstick lol.

 

Some folks ran motor oil in them, straight weight I thank, and a lot were speced for Dextron.
Google TranSynd: That is the current recommendation.

 

Allison transynd spec ATF only as others have stated. The fluid changes to a golden/yellow color under normal service and will not stay red. The color has no affect on the fluid performance. It will pour red from the bottle.

 

I think transynd is made by Castrol if my my memory serves me right. For extended oil drains, oil must meet Allison TES spec 295. When I was in the Army, they ran 15w40 in the world series Allisons. At work, we have a couple dump trucks with Allisons. We run Shell spirax s6 synthetic ATF and change every two years. Biggest killer of the trans for us has been failed heat exchangers. One tablespoon of coolant will ruin the clutch packs.

 

Allison recommends you use Transynd, which is red. You most likely have a 3000 or 4000 series transmission, which uses two internally housed filters. Before I was banned from there, I posted a how-to on Quora, which you can read here
Don’t overtorque those bolts, unless you like the idea of dropping out the pan and recutting the threads.