After driving the car for a long period of time or after a freeway trip especially if its hot out the transmission will shift funny, it will go into second a little early smothly but not normally then shifts into third again early and jerks the car then followed by fourth which again is way too soon for fourth gear and also gives the car a jerking or bucking feel and all this happens under 30-35 mph.
This doesnt happen all the time sometimes if shifts perfect and others as i described. If I stop and let it cool for a few min then its fine for a while.
Every time it starts doin it I try to have someone drive it then its fine for a while or weeks then acts up again so any help or ideas would be great. Also someone mentioned it could be the modulator valve?
Thanks in advance this has been pissin me off all summer.