I thought it was just my imagination, but on my recent trip with the truck, I thought it shifted funny. Not sure how to explain it...

Anyway, on Friday LOML and I were driving home from work, I went to take off from a light, and, well the truck wouldn't go at first, then like it got kicked in the shorts BAM and off it went... Shifting into reverse same thing. Getting going from a stop it slides into gear HARD after some serious hesitation. Shifts normally from there, no real slipping.

I parked it when we got home, pulled the dipstick, the fluid is a brownish / red or reddish brown, no burnt smell...

Been doing some reading, and while I know the odds aren't great that this will work, apparently the trannies on these trucks are sort of known for this due to a clogged filter. I am thinking a flush service with a filter and some Lucas Trans fix stuff should at least tell me if I am in for a MUCH bigger repair bill..

I figure after filter, gasket, Lucas additive, and about a case and a half of Mercon V, I should be in the thing for about $150.00 plus a couple of hours tinkering in the driveway...

Is it worth it or so I just need to buck up and drag it to the transmission shop?

A little history on the truck. Truck presently has 95K on it , transmission was rebuilt under extended warranty at about 60K miles due to a flex plate / torque converter that suffered sheared bolts. At 90K I had the trans cooler swapped with the towing package cooler as I had managed to bust the original with a winch (Don't ask, I was stupid!).

 

I'd try it, but do NOT put the Lucas in it.

 

A fluid change would be the first thing I'd try too.

The gasket is a permanent reusable type that is much better than one an auto parts store will sell you or one that is contained in the filter box.

Way back, 1970 Mustang with a C4 tranny quit downshifting when I slowed down and stopped. It would be in 3rd sitting at a stop light. I'd press harder and harder on the gas until it downshifted to first with a slam. A trans fluid change fixed it. It happened again about 50k miles later and a fluid change fixed it again.

 

Any recommendations on DIY-ing a fluid exchange? I know just dropping the pan won't touch the fluid in the torque converter.

 

The usual way to get all of it exchanged is after dropping the pan and changing the filter in your case is to put 4 qts in, disconnect the return transmission line to the transmission and run it until you get 4 qts out, stop and refill and repeat until you get all of it out. I think most people doing this at home use a little excess fluid to make sure they get all of it exhanged.

 

I see 2 different auto transmissions for the 2004 F150, the 4R70W, and the 4R75E. Which one do I grab the filter for?

 

If you have a 5.4 you have a 4R75E.

Mark Kovalsky has a writeup on several forums including this one on how to do a complete exchange yourself. I personally would rather pay a shop to do it with a machine.