I own a 01' Supercrew with a 5.4L, with about 120K and I'm not sure what transmission I have but, here lately I have a slight grinding noise coming from it while in drive and neutral.

At first I thought is was the rearend so I changed the oil and checked it out, and no change in sound, everything looked good. Then I took it to the shop and they changed the transmission oil and filter (no flush) and still no change in the sound. So I thought it might be the u-joints so I changed them, and no change.

But when I changed the u-joints, I placed the yoke back in the tranny and spun it forward and backwards. And when I spun it forward it repeated the sound, like it had a dirty bearing or like a bent rod spinning, kinda like a warpped rotor. And when I spun it backwards, no bad sound at all, nothing just smoothness !

The noise appears to becoming from the rear shaft of the transmission. I understand and am aware of the normal sounds that transmissions make, but this is not normal. And so wanted to check to see if anyone has any idea's or suggestions on trouble shooting this issue.

 

Well did a little research and I think that I have the 4R70W transmission, it has 14 bolts holding the pan....

Does anyone have any suggestions ?

 

Bump !

 

Since it happened only in one direction, the noise you heard while turning it by hand is most likely completely normal. That noise you describe might be from the 'sprag' that sits between the center support and the gearset. It will only allow the gearset to turn one direction and it locks going the other direction. When you turn it by hand it can kind of squeal.

You might also hear a clicking sound while turning the yoke. That is the intermediate one way clutch doing the same type of thing.

I honestly don't think this is your problem. I can make both of those noises on a freshly built transmission that is in perfect working condition.

Darrin

 

Thanks so much for you input ! I posted this in October ! I was beginning to think no one was out there