I am new in this club maybe 4 days old and had several of my problems answered about my Montana which was deeply appreciated. So I thought maybe I can help someone out there that has a Chevy with the Allison Trans. in it.
I have a 2003 That just turned 5000 miles. At this time you are supposed to change the external canister filter. The dealer did not know anything about this filter, he didn't know that there is a magnet inside that has to be removed and cleaned and then reinstalled. (If you do this your self when you reinstall this magnet be carful you do not get armstrong and over tighten, this will cause a leak). Make sure you use Dexron III trans. fluid, or if you like a synthetic oil, Allison recommends Transynd. I would not recommend taking your vehicle to a Jiffy Lube, they might be OK for your engine oil but not for your high tech tranny.
I also asked my dealer about changing the fluid in the future, the dealer said sure we pump it out and run a cleaner through it (power Flush) and then refill with tranny fluid (this is death to your trans) and Allison does not recommend this.
My Chevy dealer swore that this is the only way Allison wanted it done.
There is a forum you can go to to get all the information on care of the Allison, it is
www.woodalls.com/cforum. Read what they have to say about changing filters and fluid. It's scary when you take a vehicle to be serviced and the dealer doesn't know his --- from a whole in the ground. I talked to Allison personally and they told me never to pump any cleaners through this Trans. and there is no need to replace the internal filter it is for overhaul only. A person can learn a lot from these forums. Some of these Chevy dealers should use their computers for more than playing games. There is also a web site that you can down load a copy of the manual for your tranny. If someone needs this web site I will try to find it for them and post it .
I sure hope this helps someone out there, I am not that mechanically inclined and need all the advice I can get, I just believe in research.
Bill
Bill & Rita