This is on behalf of my friend's truck, an '01 F350 with the 7.3 powerstroke, seems to be some more famous transmission issues.

This issue suddenly popped up overnight. Was fine one day, acting up the next morning.

When idling in drive, there's this nasty growl/clattering noise coming from what seems like the transmission, accompanied by a slight vibration through the whole truck. The vibration and "growl" seem to be "in tune", if you know what I mean. The noise and vibration stop if you put it in park, neutral, or reverse. In drive, the noise/vibes also stop once the engine revs up past about 1200 RPM or so. The transmission seems to be shifting normally, and the truck drives totally normally as long as the engine speed stays up. Come back to a stoplight, the horrible clattering noise returns...sounds almost like an engine running with a busted rod. The trans fluid is relatively clean, no burnt smell, and no bits of metal visible.

Any ideas? Is the truck safe to drive(short term, like to get parts) or will that do more damage? So far it's got maybe 50 miles of driving with this problem and it doesn't seem to have gotten worse(or better). He's bringing it to the dealer tomorrow, and they're quoting up to $5k for transmission replacement, saying that "all these 250 and up automatics eventually go bad" and "they hear this stuff all the time".

Thanks for any help.

 

His dealer is bending him over backwards for $5k... I can get that same 4r100 transmission from the dealer for $1800 out the door, plus tax. Granted, I'd have to install it myself, but there's not $3200 in labor involved.

Does he have an aftermarket exhaust? Sounds like his downpipe could be rubbing on the tranny crossmember.

 

Since it doesn't make noise in P, N, or R I doubt that its the exhaust rubbing on a crossmember. If it was it would tend to make noise all the time. Being its an 01 and it went from being fine one day to this the next I'd put my money on a mechanical diode failure. If that has failed then the trans is already toast.


We paid $5k for a stock Ford reman trans a couple of years ago, and thats without install. More than likely thats what the MSRP on it is. Regardless if its the right price or not theres no way its worth that. You can get a BTS for $5k and not have to worry about trans issues ever again.

 

What about broken vanes in the torque converter? That would explain the noise, and the centrifugal force when it revs up quiets it. Any history of that happening?

 

Its possible, but I've not heard of it happening very often.

 

Cheers