4R100 making noise shifting into 4th.

[BBDoors]

Hey all.

I just joined the forum. Tons of info on here.

We just purchased a 2003 F-350 utility body for our fleet. It has 42,000 miles on it and seemed to be in pretty good shape.

One of the techs put it in service last week and not twenty minutes from the shop he called and said that when shifting into (4Th) OD it made a weird noise. He couldn't really tell me if it was mechanical or electronic. I took it for a drive. It runs really good. I got it to make the noise at mid throttle going up a hill. I described it as a buzz or a "Ehhhh" prior to the shift. It then proceeded to shift fine into 4th.

The Trans guy tells us that he was able to hear it and believed it to be the torque converter due to the area of the noise and the amount of metal in the pan. We had them pull it and tear it apart to determine if any other parts were damaged. He told me everything looked "really good" inside and wouldn't recommend a total rebuild. Just a new TC and a service with some updates. Even after we said we are willing to pay for a total rebuild just to be sure he said it didn't need it. That was Friday.

I told him to hold off until tomorrow to put it back together. Heres where you all come in. What do ya'll think?

[CPEsquire]

I hope that you can get back with me on this. I've had this truck(2003 F-250 4x4,7.3, 170k. miles)for 6 mo. now. I have noticed the SAME sound from my transmission. Did you ever find out what was causing it? I've been looking on this forum for some help and not found any yet. I have been thinking of doing a full trans fluid change but have heard that this will knock it out. Thanks for any help...CP

[jesilvas]

I wish he would too, but he hasn't even logged on since thirty minutes after that post was made.

[TheRobenator]

4R100's are stout transmissions and since you said 4th was OD, I am guessing it has a 7.3 in it with a 4R100 which is a 4 speed transmission. The TC goes into full lock up in OD which is where you will hear the noise, your TC is definitely going out and when it does, it will shoot clutch fibers and metal through your transmission since it is attached to your transmission pump.

When that crap runs through your transmission, it will ruin your pump, and stop up your valve body.

I'd recommend replacing the torque converter with a 2clutch billet TC since it is a work truck and it's only around another $150 for the upgrade and also go through the pump and valve body to clean it all and replace the clutch packs currently inside the drums since it is taken apart.