Loud sound in the drivetrain

[holley2346]

I can't figure what it is, and I know it could be a lot of things... so just throw out some suggestions. I basically am hearing a loud roaring sound and sometimes it sounds like when you cut metal with a band saw.... this only happens around 30 mph and up.

My mechanic said he thought it was the throwout bearings, but I'm not sure.... the carrier bearings, pinion bearings, and axle bearings looked good last time I took it all apart (about a week before this started).... also note I did run the rear end almost dry, and was pretty hot when I realized that it was leaking.


Thanks!

[onesunJ10]

More info.

So, it happens above 30mph? Only when you are in gear? Does it disappear when your foot is on the clutch? What about when you rev the motor? Does it change when you are in 4hi? Do you have a T18 4 speed? etc.

My throwout bearing went out last year and it sucked. It was a loud and obnoxious whirring sound, but it was related to the motor RPM, not so much overall speed . It blew up while i was driving and sounded like someone threw a bunch of BBs in my bellhousing all at once. I literally powershifted 240 miles back to my house.

[BigGreenMonstaWagoneer]

Yeah dude, sounds like clutch related. If it doesnt make the noise while sitting still but gets louder as you turn the engine, sounds like a clutch related deal. My Wag makes growls and such but i know when something isnt copesetic. When it makes the noise, can you feel it by resting your foot on the clutch?? It would kinda pulsate with the sound. Been there many times in my old 73 J-10 (RIP). Also, make sure your flywheel bolts are torqued..been there too. Let us know what you find out. Godspeed

[fulsizjeep]

couple questions on rear axle:
Did you flush out the axle tubes and housing after you had debris floating around in there?
Ran it dry - have the bearings and seals been replaced on the shafts since then?

[holley2346]

Originally Posted by fulsizjeep

couple questions on rear axle:
Did you flush out the axle tubes and housing after you had debris floating around in there?
Ran it dry - have the bearings and seals been replaced on the shafts since then?

It was only driven around 15 miles or so without being completely full, no I have not replaced anything.

[holley2346]

Originally Posted by onesunJ10

More info.

So, it happens above 30mph? Only when you are in gear? Does it disappear when your foot is on the clutch? What about when you rev the motor? Does it change when you are in 4hi? Do you have a T18 4 speed? etc.

My throwout bearing went out last year and it sucked. It was a loud and obnoxious whirring sound, but it was related to the motor RPM, not so much overall speed . It blew up while i was driving and sounded like someone threw a bunch of BBs in my bellhousing all at once. I literally powershifted 240 miles back to my house.

Yes, it is a 4 speed..... it really sounds like it is speed related and not rpm related.... I used to be able to let go of the gas and then push the gas again and it would stop for a while. Now it does it any time the gas petal is pushed.....

That's what makes me think that it's not bearings in the rear end, because it does NOT make the sound when the gas petal is not pushed down, and I'm coasting down the road.