I heard that it isn't a good idea to change the transmisson fluid at high mileage if it hasn't been serviced at regular intervals. Is this true?

 

No, you need to change that fluid out! When was the last time it was changed? My father owns a transmission shop and I worked there for about 6 years and he always told me that a auto trannys fluid should be changed every 30,000 miles!

 

I think that's only if the fluid is very dark and burnt smelling. If it doesn't look too bad, go get a BG Transmission Flush and you'll be good to go. A simple drain and refill gets less than half the old fluid out so you need the flush.

 

My auto tranny had 220,000 kilometers before i changed the fluid (1st time ever in 19 years) and the tranny still works flawlessly. That isnt going to stop me from doing a 5 speed swap though.

 

The flush CAN , not will cause the seals to go out because of the renewed fluid pressure not to say it will or will not work just saying that's what I know about flushing auto tranny's after about 50,000 miles with out a flush in that time/mileage

 

A flush is what she gets then.