First - I finally changed out my trans fld at 35,000 miles.. should have done it at 15 - 20,000 as a early change (if not sooner)..

Used Shaeffers 204 all trans (syn blend).. My temps droped from 170 - 180 to 125 - 160 F. Shifts much better and I will be dammed of the MPG inched up (at least it seems that way)..

anyway I have not towed much but when I put in my temp probe at 15 - 20,000 I did loose about 4 or 5 quarts of ATF by having a loose temp probe.. found out after the truck was not shifting right on corners and steep hills.. the funny thing is the temp did not go passed 180 F. at the time.. I had driven from San Antonio to Dallas.. .. Put in 4/5 quarts and believe it or not after hospital stays I forgot about doing a complete change out at the time... anyway - guess I will never know until the dam thing fails how much damage I did "at that time"..

** the shaeffers ATF seems to be good stuff to me....... don't know how at compares to AMSOIL but I have been told on a "good - healthy" trans the stuff should do as good as AMSOIL...