Transmission Fluid Change

[02_5.4Ed.B]

My 2000 Expedition with the 4R100 transmission has about 170,000 miles on it. I have not had the vehicle for that long, and I don't know if the transmission fluid has ever been changed. The previous owner used it as a plow truck. When I first pull the dipstick out after not checking it for a while, there is a grayish residue on it, mixed with the dull pink color of the old fluid. The fluid felt a little dirty when I rubbed it between my fingers the first time I checked it, but felt clean all other times. When I checked the fluid today, it felt clean again. Like I said, the fluid looks pretty dull, but doesn't smell terrible.

I'm not planning on flushing it, I'm just draining the fluid out of the torque converter and the pan. I also want to change the filter. The transmission doesn't slip or clunk, and it shifts fine other than what seems to be a delayed shift into second gear sometimes.

Does changing the fluid sound like a good idea? Thanks.

 

[0xowner]

Ah, the old debate....

I have 125k on mine... But a 4r70w... Looks old and darker but not a hard burnt smell like I've seen in many other vehicles.... I plan on doing mine soon... Only issue I have is letting off accelerator quickly at medium speeds 50 mph after some decent load up seems to seem a hard shift.

Seems strong otherwise... So I am not fearing doing it. I just bought and hope it was done once as the rear u joint and housing appear to have been replaced.

To feel more comfortable at it, do you detect any signs on maintenance on the vehicle? Bolts look removed? Rubber vs cork gasket?

 

[docraymund]

It would be best if you changed the fluid.

 

[02_5.4Ed.B]

Thanks for the replies. I'll check to see if there are any signs of previous maintenance tomorrow. Even if there aren't, I am a little more comfortable with the idea of changing the fluid now since the transmission doesn't really show any signs of a problem. I know mine has a drain plug in the pan, and I'm pretty sure the torque converter has one as well. I've got a few other things to fix on the truck first, like the neutral safety switch, but I'll update after I get the fluid changed.

 

[ExplorerTom]

Change the fluid. Drain the pan. Drain the torque converter.