Vehicle: 2003 Expedition 4.6L w/4WD, 170K miles.

So it seems that my Torque Converter is shot, or so I think. I didn't realize the whine that I was hearing, that varied with engine speed was coming from the torque converter. I thought it was a belt pulley bearing going, didn't confirm, just assumed. It wasn't until after I replaced all three idler pulleys, belt tensioner, and the serpentine belt, and the noise was still there that I realized I should have checked further.

Anyway, the noise had been there for several months, and it finally bit the dust. My wife was driving to work work, and the truck started vibrating like she was driving over rumble strips like th eones on the edge of the shoulder. She made it back home, and actually to work the next day. On the way home, the truck started losing drive power. She would see the revs go up, however, she was losing speed. She actually made it all the way home, into the driveway before it completely died. Now all gears including reverse seem like neutral.

Another person said it sounds like the main hydraulic pump. If it is the pump, does that also mean a tranny replacement?

Calling around, and asking others, everyone says to replace not just the torque converter, but the entire transmission. As the age and mileage of the truck makes it worthwhile to replace the tranny. Epecially since the failing torque converter would have contaminated the tranny anyway.

So my questions are:

1. If it is the TC or main pump, does that really mean a new tranny?
2. Should I replace with an identical Ford unit, or is there an aftermarket unit that is a better choice?
3. I also tow a 21 foot boat with a tandem axle trailer. I don't know the weight. Is there a better tranny for the towing duties?
4. Anything I missed?

Thanks in advance for any and all thoughts.

-Jorden

 

From what you say, it sounds like the tranny either needs replacing or a total rebuild. Ford offers rebuilt trannys with 3 year warranties, probably a fairly safe bet, unless you need a heavier build on it.

I don't think you have much choice about the model of tranny (for towing) just how well its built (if you go aftermarket).
My brothers 01 Expedition has the 4R100, but that is the previous generation.

Hopefully someone will chime in who knows a little more than I do.



Edit: I believe you have a 4R70.

 

Years ago my 99 made that noise, similar to driving over rumble strips at about 50mph, I figured out that it was the exact moment that the torque converter locked up. I found that changing out the trans fluid would make it quiet down. As long as I changed the fluid every 35K miles it has been fine. That happened when the truck had 70K miles on it, Ford said I needed a new trans, I now have over 268K miles and have never changed or rebuilt the trans. I do some towing and lots of driving.

Change the fluid, but you may have done more damage by driving it with burned or worn out fluid so a replacement may be your only option.

According to the service/maintenance manuals, trans fluid should be changed every 35K miles