Transmission: Drain and refill or let the Machine do it??

[BigO]

Going to change to the Allison brand, would you recommend doing a drain and refill? Disadvantage of this is leaves the old in the torque converter.

Pay some one to pump it in with a fancy machine so the pressure pumps it out of the torque converter? Has anybody done this yet? If so did it remove 90% of old or what. How many gallons do I need if I go this way?

[XLR8 2 DMAX]

I have seen little vacuums that you can purchase to suck fluid out through dipstick tube. I have never tried it, so I don't know how effective they are, but my first thought was "MORE POWER".
What would happen if you rigged a small tube to a 2HP wet/dry vacuum. Has anybody ever tried this?

[sdaver]

check out hoots long signature

[dmaxalliTech]

BigO, check out Hoots sig or email me and I can send you the directions to do it your self, easily. If your switching over, I would do a flush.

[Lone Eagle]

I used Hoot's directions. Worked great. Later! Frank ;)