Hi, I have a stock 5 speed Allison in a 2005 Chevrolet 2500HD 4WD diesel. Does anyone know the fluid capacity on the tranny? The amount is not listed in the vehicle manual, and I want to change the fluid.

Thanks.

If your draining the pan via the drain plug and changing the spin on you will need approx 7.4 qts for a stock GM pan (shallow). Buy 2 gallons. If your doing a flush via the hoot method you will want 5 gallons on hand.

Thanks. The sticky link for the capacities wouldn't load for me. I appreciate your answer.

damn 5 gallons? So if a shop told me $150 to flush my tranny and that includes new fluid thats not a bad deal then eh?

For routine maintenance, all that Allison requires is that you pull the plug, drain the transmission, change the spin-on filter and refill with almost 8 quarts of the proper fluid — correctly done and a considerable savings over what the shop wants. Make sure that you end up toward the lower end of the hot zone on the dip stick when checked at about 175 degrees F. Too, don't forget to reinstall the magnet on top of the spin-on filer. Allison recommends against flushing the transmission. Use an Allison spin-on from Allison dealer.

Do I seriously have to pour through the little dipstick hole? looking in the dark and cant find anywhere else.

Do I seriously have to pour through the little dipstick hole? looking in the dark and cant find anywhere else.

Yep aim and fire :p:

Do I seriously have to pour through the little dipstick hole? looking in the dark and cant find anywhere else.

Miracle of engineering called a 'funnel' helps here.

My dealer changed mine (next time I will do it with the kit from our vendors) and I think they overfilled it. Will that damage the tranny?

My dealer changed mine (next time I will do it with the kit from our vendors) and I think they overfilled it. Will that damage the tranny?

It is said that over filling will cause temps to rise while in service. In the long run higher temps can contribute to tranny damage. If you see that your trans is over filled on the dipstick crack the drain plug or drop the spin on filter and drain it down a little.

"Miracle of engineering called a 'funnel' helps here."
Thanks for the tip Siphon, but I was thinking of standing there waiting for it to fill thru the small tube. That'll take dam near 5 - 10 mins. I'll have to pull an all-nighter

I have the Allison 1000 Auto/Manual tap up/down. Will it be the same capacity for mine aswell?

Yes the Allison in a GM/Chevy pickup truck takes 7.4 qts with a stock pan.