as soon as my tranny warms up it wont shift
 

i own a 86 mbz 300e.. nice clean ride... with 146.000 miles.. the car starts up fine.. when its cold it will shift fine into all gears.. as soon as it warms up it wont shift after first.. or it will go first second and thats it.. i try to do it manually but still wont work.. i have just serviced the tranny and i dont know.. same thing.. any suggestions.. do you think im near the transmission shop asking for a new tranny?

items to do before making any expensive decision, check the vacumn regulator by using a pressure guage, check fluit level, if won't work start cleaning valve body.