terrible squalling sound coming from somewhere

[madtom]

My 72 highboy makes a very loud "squall" when coasting. Never when at idle, accelerating or constant speed, but almost always when letting off the gas and it last about 3 seconds. It's hard to tell where it's coming from, but it sounds like right in front of the brake pedal, which would be the transfer case.

My first thought was carrier bearing, but now I'm not so sure. I'm in the process of taking the body off now, so I'll have good access to the drivetrain soon. Anyone else experienced this or have any ideas where to start looking? Thanks for any comments.

[sargentrs]

Throwout bearing?

[cep62]

Before you take it apart , try to diagnose it.
Support the back axle with some good stands and run it.
Without a load it might not make the same noise , but maybe something close.
When you're driving , then coasting you're loading the gears and bearings differently and if they're worn can make some noise.

[madtom]

Good idea. Thanks

[madtom]

I've got the motor out and the body is off the frame, so I can see everything real good. Is there anyway to tell if the throwout bearing was the culprit by looking at? It turns smoothly by hand and everything looks pretty normal.

[Ranchero50]

terrible squalling sound coming from somewhere

Usually that's just the wife...

[sargentrs]

I've got the motor out and the body is off the frame, so I can see everything real good. Is there anyway to tell if the throwout bearing was the culprit by looking at? It turns smoothly by hand and everything looks pretty normal.

Unfortunately, not a lot you can about it now. About the only thing you can do is to try to spin it real fast to see if maybe it might've had a little play/wobble in it. How did the fingers on your clutch pressure plate look and feel? How about the surface of the flywheel? Smooth? Cracks? Glazing? How about the Z-bar (bell crank) pivots for the clutch pedal? A lot of moving/wearable parts go with a manual transmission/clutch assembly. Any of which could cause an odd sound under certain conditions.

[ezmerf]

A mechanic's stethoscope will help are a wooden dowel.

[Lee]

If adjusted correctly the Throw out bearing should not be in contact with the Pressure plate while you are experiencing the sound (coasting) ,.... that is unless you are coasting with the clutch pedal in.

Lee