Oldblue98
I'm Awesome
I remember the days of non detergent oil and guys just had to flush a old engine out that was gummed and full of sludge ! Most would use kerosene or even diesel fuel to do the deed, usually was not long smoking and excessive oil use began after all the build up was washed away from the rings etc... Transmissions is kind of same theory, And it is my idea if it has not had preventative maintenance up to this point let sleeping dogs sleep, no flush just change filter and top off.Not a chance in hell I'd change that if it was my truck. I've seen it many times when the service writer sells the job because he wants the commission coin and the trans never works right again. If it's shifting fine top it off, put in a good additive product and run it.