Have a 2004 Ford F-150 with automatic transmission and 105,000 miles. Should I take a chance and have the transmission flushed with that many miles on it? Has never been flushed before.
Get the pan dropped and cleaned, filter changed and fluid refilled with what Ford specified (no “universal” stuff).
Don’t flush.
At least drain and refill every 30,000 miles from now on.
Others will soon chime in.
Have the transmission fluid “exchange” done. This removes all the old transmission fluid instead of just replacing 30% of the old tranny fluid with the pan drop. But you still want to drop the pan to check the condition of the transmission and to change the filter. If the pan is dropped and a lot of metal is found in the pan, there’s no use in doing the fluid exchange.
I had a friend with a 1999 Thunderbird where the transmission would jerk taking off from a stop. I checked to see if there were any TSB’s that addressed this problem. And sure enough, there was a TSB from Ford stating that this could be caused from oxidized transmission fluid, and that the transmission fluid should be replaced with a transmission fluid exchange machine. I did the fluid exchange and the problem went completely away. Before I did the exchange, my friend never believed in fluid exchanging of the transmission fluid with one of these machines. After the tranny service, he’s now a firm believer of these machines.
Tester