FJ40 Loud Screech / Grinding Noise

[animalk]

Hey guys,

I was wondering if any of you guys could help me diagnose what's wrong with my '72 FJ40. It just recently started screeching really loudly when I would accelerate as if metal was grinding on metal-- super loud. However, when I would press down on the clutch, the noise would disappear. Only when I started accelerating would it make that horrid noise. However, sometimes after several minutes the noise would disappear altogether, but it has not disappeared ever since today. It seems to be permanent now. Could it be a throwout bearing? It's my daily driver so I need to get this fixed as soon as possible. I have a 383 stroker sbc, SM420 tranny, 4-spd manual, Holley carb. Really appreciate any help. Cheers.

 

[bj40green]

Does it follow the rpm's?
Depress the gas pedal and it starts screeching but disappears when you let it fall back to idle?
Does it increase with the headlights on? ----> V belt. Check tension.

Rudi

 

[Rocky_LC]

Have you gotten underneath the truck and checked everything?

Loose bolts (possible misalignment), looseness in any of the driveshafts, excessive play? If you grab the driveshaft, can you shake anything between the TC and the rear differential (indicating play in either the TC, or the rear pinion bearing)?

Help us help you.

Rocky

 

[driveshafterw]

Hey guys,

I was wondering if any of you guys could help me diagnose what's wrong with my '72 FJ40. It just recently started screeching really loudly when I would accelerate as if metal was grinding on metal-- super loud. However, when I would press down on the clutch, the noise would disappear. Only when I started accelerating would it make that horrid noise. However, sometimes after several minutes the noise would disappear altogether, but it has not disappeared ever since today. It seems to be permanent now. Could it be a throwout bearing? It's my daily driver so I need to get this fixed as soon as possible. I have a 383 stroker sbc, SM420 tranny, 4-spd manual, Holley carb. Really appreciate any help. Cheers.

hey doesthe truck vibrate to i bet it does but because its old youve overloked the ujoints

 

[sggoat]

Agree w/BJ40Green--check the V-belt tension--~1/4" movement when you push on the belt hard.
If the belt looks ok, the next place I would look is the clutch pressure plate---The throwout bearing is only under side pressure when you push the clutch pedal IN,

 

[shelfboy1]

sounds like the to bearing .it may not be adjusted right and is spinning all the time but if its screeching its probably to late.i have punched a hole in the tin side of it and greased them and they lasted for years. i would check the belt tension as suggested first. ive had u joints clunk and bang but never had one screech the fact that it goes away when you push the clutch kind of leans to the to bearing .if thats not it then maybey the pilot bushing has dried out .good luck

 

[RWBeringer4x4]

Screeching/grinding sounds to me like a clutch bearing too. My throw-out bearing "chugs" at idle, you can hear it at the beginning of this video that I recorded for another MUD member, when the camera is still inside the cab:

http://www.youtube.com/watch?v=Wy7BYn2DwFs

My guess is, as the bearing gets worse, it will go from "chugging" to grinding or screeching.

Could also be the pilot bearing, but if something is misaligned, it's probably the T/O Bearing.

 

[driveshafterw]

have you narowed it down