Tranny fluid ??

[96ccdd]

Can the standard fluid in the Allison be mixed with full syn fluid .........say Amsoil torque drive ? I want to change my fluid and swap over to syn.

Thanks

[DmaxMaverick]

All of the synthetic ATF's I'm familiar with claim to be fully compatible with non-synthetics. As long as both fluids have the same rating, there should be no problem. The factory fill is Dexron III. Amsoil TorqueDrive is compatible with any Dexron III. Have you considered doing a fluid flush/replace? Search previous posts in this forum. Lots of good info.

[96ccdd]

After reading many post I'm thinking of doing a flush. Many people refer to Hoot's notes which I have been unable to locate. Can anyone help out here ?

Thanks

[DmaxMaverick]

Its really very simple.

Drain the pan (don't remove, it has a drain plug) and replace the plug. Refill with about 8 qts. Don't worry about the fluid level yet, you're just going to pump it out. Remove the "from cooler" line at the tranny (top line), and install a hose onto it. You don't need the hose, but it's sure a lot less messy. Direct the hose (or fluid path if no hose) into a large container. Baffle the stream, as it can come out quite fast. I used a plastic Gatoraide bottle with the bottom cut off. With shifter in P, and E-brake on, start the engine, and keep at idle. Watch fluid stream (helps to have another set of eyes). As soon as it starts to slow down, turn off engine. Add about 8 qts, start engine and watch stream again. Shut off as soon as it slows down. Repeat these steps until you see a color change in the fluid, or you have added about 15 qts. Stop the flushing and replace the cooler line. Be sure it snaps in good and solid. Replace the spin-on filter, and don't forget to remove/clean/replace the magnet that should come out with the filter. Fill up to the "full cold" level, which should be about 8 qts. Bring the tranny up to operating temp. A short drive should do it. Drive in a manner that keeps the torque converter unlocked, like under 50 MPH, not in T/H. This will warm the tranny quick, and cycle as much fluid as possible. Recheck the fluid level, and fill up to the "full hot" level. Check for leaks. Drive it normally for a while (a couple days or warm-up cycles), then check the fluid level again. Done.

If you have a service station available with a passive flush machine and the connectors, you could go that route and avoid all the mess and disposal. Be sure their flush machine is PASSIVE. It's important to let the tranny do all the pumping. Using a powered machine can damage the tranny. Don't let anyone tell you different!

Good luck.