Hey guys, i have a 2002 F150, with the 4.6. I have just over 127,000 miles on it. I had a full transmission flush at 50,000 then kinda didn't touch it until last week. I had the pan dropped, fluid changed and filter changed. The tecj suggested not flushing it, but dropping the pan instead, due to the higher mileage. Got the truck back, and it's been great, shifts fine. My question is, since there is not a drain on the t.q., will this fluid eventually mix with the new fresh fluid i had swapped? I honestly don't know a ton about the way t.q. work, i know i had a turbo 350 i swapped in my Cutlass when i was younger.. we filled the t.q with fluid before installing it on the tranny.

Will the transmission fluid mix from the t.q.,and if so, should i go back in a few months and have the same procedure done again, drop the pan and change the filter and fluid, to try and swap out more of the fluid from the t.q.?
Does any of this make sense, or am i just rambling about.. someone stop me.,.

 

The fluid in the torque converter will be thoroughly mixed with the new fluid in the pan in the first minute or so after you start the engine.

I would have flushed it. It doesn't make sense to me to only change half of the fluid, and then mix that new fluid with an equal amount of old fluid.

 

Totally agreed.

Darrin

 

Well, when i talked to the tech prior to having the service, he said he was concerned that since i had gone so long without servicing the transmission, he was afraid the flush would dislodge gunk and possibly caused problems after the fact. Seemed somewhat logical to me, and i searched on here and found several arguments for and against the same issue, so i took the road less destructive, at least in my mind, lol...i just know i can't afford to rebuild a transmission right now, saving for a wedding and honeymoon..
So, should i have flushed it?

 

When you drop the pan you get about 1/4 of the fluid out of the system, and yes the new will mix with the old. The tech should have suggested flushing the system first through the old filter, then dropping the pan and replacing the filter.

 

A "flush" does NOT dislodge gunk if the machine is used in the simple "fluid exchange" mode - the machine doesn't pump anything, the engine is idling during the exchange and the transmission pump itself is pumping the old fluid out and drawing the new fluid in. In other words, it's doing exactly what the transmission does whenever your engine is running anyway!