I and my husband are new and unfamiliar with this tranny. Please answer the following:

What tranny fluid do you use?

How often do you change it?

What filter do you use?

Dexron 3 is what the factory recomends and is a good choice if you use a name brand fluid. Synthetic fluids are the choice for the Allison because most people with these trucks work them or race them. I like Mobil 1 atf, TranSynd is very popular among the members here and is recomended by Allison. There are other synthetic fluids that are good, but I have no experience with them. Fluid changes depend on fluid used ( dino or synthetic). A name brand Dexron 3 is good for 15,000 miles, where as a synthetic fluid at least doubles that mileage. I use Allison spin-on filters ( red with Allison logo) and the sump filter (in the pan) is not necessary to change for 50,000 miles although I would change mine at about 30,000. I change my spin-on filterat every engine oil change ( 5,000, I use Delvac 1). It is not really necessary to do the spin-on that often or is it. Hope this helps.

mike

I've never changed any of my vehicles over to synthetic. Do you have to flush out all the old oil before you fill it with synthetic or, is it just like a normal fluid change?

Before I went with my stagev suncoast I put Amsoil synthetic in my original tranny by just draining what I could and filling with amsoil. It made a difference in the feel of the tranny, much smoother. I have Royal Purple synthetic in the suncoast, I don't know if it's the best to run in there but it sure feels good.:cool:

I think I'm going to use Amsoil for now. I've heard of Royal Purple and their site says they recommend their product for diesels after 8-10k miles-I'm at just over 3,100 miles now. I think I will give that a try then.

in the trans I would run regular old non syn dextron mobil 1 syn if you want syn or if you want amsoil I would make sure you use amsoils "torque drive"(I believe thats the name of it) and NOT thier regulare dex 3 replacement atf

oh yeah.....allison filter(dont forget about the magnet!)

no sense to dump a few quarts of synthetic fluid in there, run all synthetic or conventional. I would say drain the pan once a year and replace what you drain off if you are using regular atf and non synthetic. I like to change my trany filters every oil change.