We're getting a squeak that seems to be coming from the transmission in a 2001 Expedition with 4x4 when it's shifted into drive or reverse and the engine idling.

I can lie on the floor and clearly hear it and it's just loud enough to be detectible in the cabin with the windows up.

Putting the parking brake on and increasing RPMs slightly either covers up the noise or reduces the noise.

There is NO squeak in park or neutral.

The squeak is associated with engine RPMs.

Engine oil changed, tranny fluid looks and smells OK, I changed tranny about 2 yrs ago and probably have 15,000 miles on it, new one is a Ford rebuilt, about $2000, exchange.

The noise happens in drive and reverse and I can't pin it down.

Any suggestions what else I could try?

 

Did you put a new torque converter in when you did the tranny?

 

Yes, the rebuilt xmission came with a new T-C.

 

motor or tranny mount loose maybe? check the rubber mounts for play

 

Nope, not that kind of issue.

 

The noise seems to be getting a bit louder.

It is sort of a chirp like 2 pieces of metal rubbing a part on each engine revolution.

It is sensitive to RPMs and seems most pronounced at idle [about 750] in reverse or any forward gear but not noticible in park or neutral.

Over 825 RPM the chirp goes away -or is covered up by other noises.

It definately seems to be coming from the transmission and is definately controlled by the gear shift.

I'm wondering if something like a piece of rock got into the torque converter some way. The rubber plug in the bottom of the bell housing is still in place.

I hate to think I'll have to pull the tranny out again to change the T-Q.

Does anyone know if the T-Q can be changed without completely pulling out the transmission?

Fortunately I just bought the 4 mobile column lifts I used 2 years ago to change the tranny. They are like a dream come true.

 

In all seriousness, have you looked under the truck and on top of the tranny and transfer case for a bird's nest? Seen it happen before.

 

We just looked and there aren't any nests or cats, or anything.

 

UPDATE

On the off chance the belt was squeaking and making the sound appear behind the engine, picked up a new belt and pulled off the old one.

While the belt was off ran the engine and probed the engine and tranny w/ a stethoscope. Although I could hear the squeak by ear, the steth didn't detect anything.

So removed the vibration probe from the stethoscope and stuck the end of the plastic tube into a 2 foot section of garden hose to make a sort of coupled high frequency audio sensor.

Worked well and I was able to pinpoint the squeak to the area between the rear of the engine oil pan and the cover plate on the tranny bell housing.

Very loud in my stethoscope.

So, that leads me to wonder if I properly torqued the T-Q to the flywheel or if there is some sort of debris in there. It's been so constant over the past week that I doubt if it's debris.

I can't remember exactly how the T-Q attaches to the flywheel [I have pix of the job somewhere I think]

If I pull the sheet metal cover off the bell housing, will that allow me to check the torque of the attaching bolts?

Does anyone have an idea what may be going on with this new info?

 

What about the tranny to engine bolts, are they tight?

 

Found pix but they were no help w/ this.

I think the transmission to engine bolts are tight because I remember the top 3 or 4 were a real PITA to get to.

I'm getting the 4 column lifts figured out, [they are the 7 1/2 ton -apiece! ones for lifting buses and trucks with 6 but I have only 4 and that's perfect. Very compact actually. A buddy had them and I've had to go over them and figure out why they weren't working, [safety switch] and the 3 phase detector was tripped and had to figure that out. Just needed to reverse a phase. But he didn't mess them up in any way, it was me trying to take a short cut and not hook them all up when I did initial testing.

So now it's time to raise the expy and look to see if I can figure out what's going on.

 

Raised it up, pulled the small cover held with 2 bolts, checked the flex plate bolts to be tight, all OK.

Listened again with the modified stethoscope after removing the rubber plug on the bottom and the left side and probing around.

The sound is definately coming from the torque converter or something is rubbing on it.

The sound only happens at idle after the truck is put into gear in rev or drive.

So, it seems to me that something INSIDE the T-Q is making the noise.

I wonder what kind of ATF I should be using on this recently replaced T-Q? Mercon or Mercon 5?

 

There is one other possibility. The front bearing (input shaft bearing) for the tranny is seized and is spinning within the housing.

 

Why would changing [at idle] between park/neutral and drive/rev make a difference then?

 

I know this is an old post but was this ever resolved ? I think I have the same problem right now