So I've been daily driving my '77 F250 4x4 for about a year, pretty trouble free. The truck has a 460 with a T-19 that the previous owner swapped in. As far as I can tell its from an 80's truck. The divorced transfer case is stock. The install is pretty clean and looks like it was done some time ago.

This week a new noise developed when decelerating. Its a squealing sound only when I let off the throttle and the clutch is still engaged. If I push in the clutch, the noise stops. If I touch the throttle, even just a little, the noise stops. But as soon as I let off the throttle, the squealing sound starts and will continue until I push in the clutch or press the throttle. It doesnt happen as much at higher speed, most noticeable below 30mph. The noise seems to be coming from the transmission area and is noticeably loud.

Could U-Joints make this noise? I've only had them squeak at me, never this loud squeal sound. My other thought was a bearing in the trans or transfer case?

I know its very difficult to diagnose over the internet, just hoping maybe someone has seen this issue before. Thanks for the help!

 

Could be the clutch throw-out bearing.

 

I'd like to think it isnt because I just did a new clutch, throwout bearing, pressure plate, pilot bushing, ect about 6 months ago. But with the quality of today aftermarket parts, you may be right

 

I hope it's something else, but my first thought was throwout bearing too.

 

After driving home from work yesterday I really listened to where the noise was coming from and I think you guys are right. Looks like I'll be pulling the trans

 

Check your carrier bearing first, if you have one. Mine is not all that far back from the transmission.

 

Problem solved! I put the truck on the lift to pull the trans. As I was pulling the intermediate driveshaft, I noticed one of the caps was cracked on the front u-joint. Quick run to the parts store, $12 and an hour later the noise is gone!

 

Glad you were able to fix; not trying to hijack the three but the way everyone talks about the throwout bearing it sounds quite ominous.

I was told on here that the throwout bearing could be why my F100 make whistle/whir noise when the clutch is fully depressed.

What all is entailed with replacing it?

 

I can think of several things that would make noise with the pedal down. One is the throwout bearing, another is the pilot bearing. Also, if the disc isn't fully released by the pressure plate, it could make noise. Most likely is the throwout bearing, it sees a lot of force and speed change every time you push the pedal down.

Pilot bearing will make noise with the pedal down in gear, throwout bearing will make noise any time the pedal is down as will a disc that's dragging on the pressure plate/flywheel.

Changing the throwout bearing is pretty simple, just requires removing the transmission. You might want to replace the disc, pilot bearing and pressure plate since you are in there anyhow. Pressure plate/disc change requires a centering tool which usually comes with the kit. Pilot bearing requires pulling the old one and that is either done by filing the cavity with grease then smacking a solid round object that fits the inner bore of the bearing in the vain hope it will pop out or renting a pilot bearing puller form the auto parts store.

I have not been under a 3 speed vehicle in MANY moons but imagine it's much lighter then a C6 and know it has less stuff to disconnect and worry about It's probably not an afternoon project for a beginner but is easily done in a day.

Michael

 

Sounds like a chore, good to know and thanks. I've only done motor side stuff so I might have to enlist some seasoned help when I decide to tackle that.