Tranny Flush

[jhm]

Had mechanic do complete tranny flush at 50K, took down pan, took out filter, flushed, new filter and fill. Thinking now at 110K doing it again. No problems with tranny so I am thinking leave it alone?

[Doug_Scott]

Transmission fluid change and flush is one of those items that you will get both for and against recommendations. I have not owned a vehicle long enough to even consider changing the fluid. Even going back to when I was the transmissions mechanic at the dealer it was not a clear cut answer as being a standard maintenance item. What usually happened back then (70's and 80's) was that people would get the transmission fluid and filter changed because the transmission was either just starting to act up, or someone noticed the fluid was very dark, and smelled burnt. Changing the fluid and filter under those conditions would more likely than not create fatal transmission issues within 2,000 miles. That nice clean fluid would dissolve the varnish that was sealing the transmission up inside. That was on the non-lockup converter transmissions, and the first generation lockup converters.

 

With the transmissions today, I would follow the manufacturers service schedule, and follow the severe service level. No one drives the normal level. The key is still the same for the first change though, if the fluid is dark and burnt smelling, changing it may actually create an issue in short time. You should still change it, just saying do not expect it to cure anything, and do not be surprised if it does fail afterwards.

 

To the OP, you have started a service interval, I would keep doing the change with the flush every 50k. The flush is necessary due to lockup converters.

[00Silverado4x4]

Just me personally but I'd just do a pan drop/filter change and skip the flush. That's what I did on my truck.