[THEFERMANATOR]

Originally Posted by Skools Out

there's no drain plug in a trans on the GM stuff.

Many of GM's trucks came with drain plugs after 97, and my ALLISON DEFINATELY has one. I for one personally believe in changing the fluid AND filter every 30K for a daily driver, and every 15-20K for a vehicle that gets worked. I've seen WAY too many GM trannies get diagnosed as bad or fail because of lack of maintence. And when I was at DODGE you could tell if one hadn't been changed by how loud they were on a cold start. After about 40K miles the tranny will howl on a cold start if the fluid hadn't been changed. The problem with fluid changes is if you haven't kept up on it by the book, then don't do em at all. Once you go more than 30K without a fluid and filter change you will get particle build-up inside the valve body. If you change the fluid and filter after this has gotten built up, the fresh additives in the new fluid will almost certainly clean that build up out and deposit it in areas you don't want it.