I changed the fluid and filter in the trans yesterday.Just a pan drop,left the pan down for a few hours to get as much out as possible.My question is how long or about how many miles to heat up the trans? Dip stick levels say cool marks 70 and hot marks 180 degrees.If I check the fluid in the morring(trans cool) the level is at the top of the cool marks.funny thing is I drive the truck over 10 miles,check it again level is still at the top of the cool marks.levels checked in N on level ground,its a 4by4 with the trans cooler.I have put in 8.5 quarts of fluid.Is the trans just not getting hot or what?