On my new 55 F350 there is a whirring noise when the truck is moving. The noise is there going forward and backward, in gear as well as coasting, truck engine running or not. The noise goes faster as the truck goes faster. It sounds like it is coming from directly below the cab.

My mechanic friend says without looking at the truck that it might be the emergency brake band around the end of the transmission. He said maybe something made a nest in there. I crawled under the truck and looked but saw nothing.

What do you think? Is it the e-brake? Or could it be something else? I guess I will have to put the rear end up on jack stands and run the truck.....

 

Does it have a pto? I don't understand how it could be making the sound without the engine running though. .
Doug.

 

No PTO. Is obviously something in the drive train. Could it be a universal joint in the drive shaft.

 

Abe,


Just a guess, and maybe not a good one, but does the drive shaft have a carrier bearing on your truck?


B

 

Yup Abe, I'm also thinking "U"joint by the way you describe that sound but Oldb might be on to something if you have that bearing.

 

Doesn't the drive shaft stop turning when the clutch is disengaged?

 

Only if your stopped

 

Let the truck roll slowly and pull slightly on the e brake handle, see if any change in sound. Could be u joints, driveshaft center bearing, e brake, wheel bearing or in the rear end - differential.

 

Abe, call Chuck's Trucks for the carrier bearing and u joints. I just bought some and he had really good prices.

 

That is a good idea, Ray, to rule out the e-brake. It's not the rear end differential. The sound is coming from below the cab.

 

I just noticed a similar noise coming from my C-6 tranny during a local cruising show. I was pretty sure it was from my parking brakes because I hadn't yet adjusted them after putting in my new rear end.


I put it up on jack stands and started it up and put it in gear and the noise was still there. I got underneath and started tracking the sound and followed it to my rear tail shaft on the tranny. I couldn't see anything obvious so I decided to check the tranny fluid, DUH! I was almost a Qt. low. I added fluid and the noise stopped right away. I test drove the truck and it didn't seem to cause any permanent damage. Hopefully I caught it soon enough.


I hope your problem is just as simple to fix.

 

U-joints don't make a whirring noise. A worn or bad U-joint makes more of a chirping noise and will change as load and speed varies. Might be a bearing noise, but that's more of a howl. I'm thinking it's a gear noise. Has it always been there? Does it change volume or pitch depending on load and/or speed? Some manual trans just have gear noise, because of the gear design. Especially on larger trucks.


Are you certain its not coming from the rear axle? These bearing noise characteristics are often associated with rear axles. Does it get louder when either accelerating or decelerating? Does it change when going around a turn? A rear axle gear noise will often only occur at particular speeds or range of speeds. Or will change volume when accelerating or decelerating.

 

Abe for years I had a horrible whining noise in my truck it was annoying and sometimes gut wrenching! Finally after the divorice it was a great quiet and peaceful ride!!!

 

It doesn't get louder when accelerating, it gets faster. It doesn't change going around a turn, well I do not know because I cannot really hear it at higher speeds because of engine noise or it is "spinning" so fast I don't hear it. I think it is coming from right beneath the cab. Or is the noise just coming through the hole where the emergency brake comes through the floor board.

Thank-you, all.

 

Is there oil in the transmission? Un-oiled gears would make noise in all directions and whether or not you have the engine engaged but are moving?