I have 136k on my 95 Auto, and I recently took it in for routine transmission service. On the work record I was given when I picked up the car it said they had put in synthetic trans fluid. Know I have noticed that the trans fluid is shifting differently, especially on the 2-3 shift, the RPMs actually briefly rise during the shift, and it seeems to take longer to shift than b4. Should I be concerned ? Should I take it back and have them take out the synthetic ? Your feedback appreciated...

 

Somehow, your trans is now slipping on the 2-3 shift. That's really not good at all.

 

Thats what happens when you change transmission fluid on a car with high mileage... Sounds like your going to need a rebuild...

 

I'm very surprised that they put in syn without your approval. Typically, syn is more expensive, hence the customer approval. I had a 94 that I changed the tranny fluid at around 150K. I put in cheap organic stuff with no problems. I would take the car back, verify what they used and have them put in regular organic stuff.

 

Synthetic wouldnt cause his transmission to go bad, hes 1,000,000X's better by putting in synthetic than regular oil, especially in the transmission.

 

That's what happens when you spout old myths

 

I just talked to the the auto shop that did the service, I am going to take it in tomorrow and the service advisor is going to ride with me to see what i'm talking about. of course he gave me the whole deal on 'if the trans had never been serviced b4 then changing the fluid causes problems, etc.' BTW the synthetic fluid cost $70

 

Ideally, you shouldn't have problems changing at that mileage or using synthetic. Your tranny and ECU may just need time to adjust to the new cleaner fluid. Remember, the new fluid will have different properties than the old dirty fluid. I would look at the specs of the synthetic and compare that to the owners manual, just in case.