The Stovebolt Site Forums The Shop Area Engine Shop Squealing engine noise

Okay Stovebolters my truck is now undriveable and I need some direction:
When driving the truck if I hit a bump or sometimes randomly it will begin to squeal, very loudly. It stops only when you stop and are at zero speed. It does not squeal at idle or when revving it in neutral. It still squeals with generator belt removed. Clutch is correctly adjusted for pedal play about 3/4” of travel before it engages. As above I cannot replicate with the truck in the driveway it only happens at speed. Is this a harmonic balancer issue or something else? Truck drives fine except for the intolerable squealing. Engine is a 1954 235, rebuilt by the previous owner, it has 15,000 miles on it since it was rebuilt in 2006. Thanks for any help.

Hy Brad Allen, if you could find an isolated road for test driving purposes, when the squealing starts, shut the engine off and coast, just to confirm it is indeed the engine making the noise and not other rotating parts. Let us know what you find out, good luck.

It could easily be a water pump, generator bearing, or similar part that starts squealing after things warm up a bit. But you've eliminated the water pump and generator by removing the belt) The shaft of a bearing that's worn may start "walking" around inside the bore, (chattering from side to side) and cause the squealing. A bump can cause that to start and another bump could stop it. Is it speed related (change pitch with different speeds)?
Anyway, my vote is a bearing. I'd check the front wheel bearings first to see if they're binding up, possibly causing the inner race of one to chatter on the spindle.

When doing a test drive for a noise, driving along a wall really brings out the noise.

Ed

Open drive? Dry u-joints.? Metal timing gears clashing?

Brad, could this possibly be a "wind" noise ??? I'm reaching here but your info kind of leads me in that direction.....I like the idea of driving along a wall and also, someone riding on the back when doing so....you know, left front, right rear ect ect.....

I am going to check some things today if the weather holds, this is a squeal it so loud people walking turn and look.

Try coasting with the trans in neutral and the engine stopped, or get somebody to tow the truck with a chain to see if the engine is actually the problem. It sounds more like you're hearing a brake, U joint, or rear end bearing noise.
Jerry

Thanks Jerry I am hoping to do that type of testing weather permitting.

I'm going to guess a wheel/brake problem , maybe a broken brake return spring caught up , or even just a stone in the brake . As Jerry suggests , coasting may help identify the source.

My guess is a U-joint. I had a squealer like that too. Coast in neutral to take the load off of it. If it goes quiet it's probably a U-joint.

I assume this is a one piece driveshaft but if not then check the midship bearing.

OK Brad, we can't have one of our first string quarterbacks on the sidelines.
Has this problem been sorted out? Inquiring minds want to know.

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