Allison Transmission Fluid Change

[Jerry Sanders]

Greetings, today I started to change the fluid in our transmission.  I viewed the video for some helpful instructions and jumped under to drain the old fluid.  The video states that the pan holds approximately 4.5 gallons but I have much more than that in my drain pan.  The video says a filter change will result in the loss of 2.5 gallons.  I did not change the filters because they were done last year.  Did draining the pan also drain 4.5+2.5 gallons of fluid?  I have 5 gallons of TES-295 to replace the old stuff or was my tranny overfilled or do I need 7 gallons to refill? Help....

[Gerald Farris]

Jerry,
I can not answer your question from my experience because I have always changed the filters when I changed the fluid, but I would estimate that changing the filters accounts for only about a 2 quart fluid loss. So since my coach (same model as yours) uses 7 gallons of fluid for a drain and refill with filter change, I would expect a drain and refill would require in excess of 6 gallons.

Gerald 

[William Ervin]

I'm with Gerald,  I change the filters with the fluid, they're spendy so I can certainly understand why you wouldn't if you changed them last year.

I got about 5 gals out of mine when I changed the fluid/filters and the computer was showing 2 qts low before I changed it.  I put about 5 1/2 back in and when I checked the computer after a warmup drive I was showing oil OK on the computer. 

When I pulled the filters after draining, I got maybe 3/4 to 1 gal out of the filter area.

Bill