I have a 99 suburban wit 186k, when or should I change transmission oil filter and oil. I 've been told to never do it. Is this corect?
Youch! Are you saying that your trans fluid has 186K on it?
You should have the transmission pan dropped and filter replaced every 30K miles. So you should be on about your 6th trans service by now.
Take it to a local, independent shop that specializes in transmissions. Have them drop the pan, inspect it, and change the filter. If anyone suggests a “flush” I might consider it but only AFTER the pan and filter have been done.
If you are asking b/c your trans has started acting funny then it might be too late, and don’t be surprised if you find people reluctant to service it.
A flush “may” be problematic with older, un-cared for transmissions, but fluid/filter changes are always beneficial.
The person or persons who told you to never change your transmission fluid should not be allowed around any kind of machinery. Also, if this person has his own vehicle, you might not want to ride in it. Automatics must be serviced every 25-30k miles regardless of what your owners manual or salesman says. Drop the pan on your Suburban, change the filter and refill using Dexron VI, it should take 5 quarts to refill.
I agree with transman. This is the one thing I disagree with in the car owner’s manual.