i have never had a problem taking the drain plug off. me or my co-workers. but then again you arent really replacing all of the fluid. but lucas huh? what about mobil one? they make a synthetic atf.

 

I used Mobil1 for quite a time. I feel it is a good ATF, synth, I mean, I do not use conventional ones unless car leaks or burns fluids.
I found that Royal Purple, though, quietens transmission much better than M1. Also, they have dropped price on their ATF. That's a double wemmy.
I know I am not replacing much of ATF. neither does draining via drain plug, replaces maybe a 3rd of the whole entire volume.
I know that I have to bend gear shifter bracket to remove the pan. Maybe I'll tackle this around warm times. I have already been through the "I am all soaked in ATF" attempt last summer. Damn bracket!!
But I also know that I am not the only one who can not remove the drain plug. There was something about it being locktited. I hope, I'll be able to rip it off with SureGrip though.

 

told you I'm not the only one, though mine is not rusted at all:
http://www.truckforum.org/forums/gmc...-question.html

 

LOL, I know what you are talking about. On one side you have the shifter bracket and on the other you have the litte tin heat sheild bolted to the side of the trans. I wanted to give a word of caution also, on the newer trucks, say 96 and up, they are running the exhaust down behing the trans pan. When you go to pull the pan down with that pipe there, if you are not careful, you will break one of the shift solenoids because it is so tight trying to get the pan out. I would recomend using LubeGuard as an additive. It does not build sludge, it lubes the valves good and it is a good friction modifier. Hope this helps.

 

yes, another reason not to mess with that pan. there are 2 solenoids in the rear of it, with short poorly snug contacts, that can be easily loosened when reinstalling the pan. THEN, you get lotsa trouble. and a big do-over.