You can clean the battery yourself with water and baking soda... So far as the transmission, I change my spin on filter every 15000 miles, also pull the trans drain plug and about 7 quarts of fluid will drain. Refill with fluid and replace spin on filter. Spin on filter is $28.00 at GM dealership, about $11.00 online. Filter screen in the pan is replaced when the transmission is rebuilt. GM does NOT recommend flushing the trans, just replace what you drain from the pan when replacing the spin on filter. My truck is a 2001 3500 with 110000 miles with probably 100000 of that towing better than 10,000#. This is what Allison says do!! http://www.allisontransmission.com/servlet/DownloadFile?Dir=publications/pubs&FileToGet=SA5429EN.pdf Source for spin on Allison 1000 series trans filters... They are about the same price at an Allison dealer/repair shop. This is the Fleetguard number, they will run about $15.00... Fleetguard HF35296 http://madjacksynthetics.com/Allison-1000-Transmission/Parts-Pans-Etc/Allison-Spin-On-Oil-Filters-29539579/prod_13.html | 
GMC 2500 Duramax/Allison - Dealer says needs x,y,z....
