Do I have to drop the pan to change fluid?

[Magumba]

I have a 2003 Workhorse chassis with an Allison transmission. I planning to change the fluid. Is it ok to only remove the drain plug when draining the old fluid? Should I also remove the pan?
Thank you for your help.

[04Crescendo]

I have the Allison MD3000MH and there was no reason to drop the pan when I changed fluid and both filters. The drain plug pretty much emptied it. The 2 filters unbolted independantly. It was easier than the toad transmission fluid/filter change where I did have to drop the pan.

[edgray]

Quote:

Originally Posted by Magumba I have a 2003 Workhorse chassis with an Allison transmission. I planning to change the fluid. Is it ok to only remove the drain plug when draining the old fluid? Should I also remove the pan? Thank you for your help.

True that only pulling the plug will not COMPLETELY empty the pan, however that is all that is recommended because dropping the pan "may" require a new gasket / seal and therefore isn't worth the risk. Plug draining will yeild about 10-11 quarts of old fluid depending on how long you let it sit before drain. A short drive in between two fluid drains will ensure you have close to 100% new fluid, but you will need to buy 5 gallons to do the double drain procedure.

Please replace the fluid with a TES295 approved fluid like TranSynd.....DO NOT use Dexron VI (6) because it WILL damage the seals in an older Allison like yours.

Also change the spin on filter using Allison part # 29539579 and reuse the magnet, after wiping it clean.

Have fun, it isn't that hard a job...just expensive
Ed

[Rocky Larson]

I did not remove the pan on mine. Look for and reuse the filter magnet. There should only be a small amount of fine dust adhering to it. You should only have one DIY filter. The second is internal and only needs to be done on overhaul. I switched over to Transynd with the two change procedure but took more that a few thousand miles to get around to the second change.

[Magumba]

Thank you for your help. I'll be doing this soon.