FJ 60 Jingle Noise (1 Viewer)

[earthcruisersteve]

HI All,

I have had my 85' FJ60 for about 8-9 years now. Body/chassis has 212k miles. Engine has close to 160k miles from donor 84' truck paired with a rebuilt t-case with an advanced adapters 4:1 low gear set and a new h55f transmission.

I have developed an odd jingle noise while under load. When the clutch is pressed the noise goes away. From research i believe it to maybe be a TO bearing or something to do with the clutch plate assembly. However, the noise is extremely inconsistent and is louder at low speeds and sometimes non existent at high and low speeds. The Jingle noise seems to have happened around the time of my engine swap or desmogging of the new engine, my memory is poor, but those two jobs were done close to each other.

The noise does not occur at idle or when i rev the engine in neutral. When the windows are closed and driving, the noise seems to come from the rear of the truck and when the windows open the noise is hard to locate. I get no vibrations while driving. The noise sounds like a set of keys slapping against the frame rails at random times, but consistent enough when under load and not in neutral.

I have checked every nut and bolt under the truck from drivetrain components to the bolts holding down the bumpers. I even tried sticking a bore scope in the frame rails to see if a bolt or bell got thrown in there. One thing i found was a bit of slop in my rear differential in/out and side to side, could it be that?

I have scoured the forums, any help is appreciated.

Thank you!!

 

[OSS]

Could one of the heat shields above the exhaust pipe be rattling? Check them all

 

[BlackCat]

Have you checked the exhaust pipe clamp on the drivers side frame rail right around the firewall? I've left it loose and it rattles exactly like you describe, but not from the location youre describing.

 

[CruiserTrash]

Have you checked the exhaust pipe clamp on the drivers side frame rail right around the firewall? I've left it loose and it rattles exactly like you describe, but not from the location youre describing.

There's also an exhaust hanger that bolts to the bellhousing. At that spot the exhaust goes through a very skinny opening between the frame and bellhousing, so that hanger could be hitting either one and the exhaust pipe.

What about some kind of check valve that's gone bad, maybe with loose components like springs & diaphragms inside? PCV valve, the air check valve between the smog pump & air rail, or between the smog components on the left fender and the exhaust (firewall below the brake booster).

How about some coins or keys they fell below a seat and migrated underneath the carpet?

Loose temp sensor in the cat? Loose baffle inside the cat?

Loose clamp for the fuel & brake lines running along the right frame rail?

I drove over a pretty washboarded road this summer and had stuff inside of my starter loosen up. When I removed it, it jingled when I shook it.

The fact that the noise goes away when the clutch is pressed immediately makes me thing it's one of the following though:
-bad throwout bearing
-loose clutch fork
-loose finger on the pressure plate
-etc

 

[earthcruisersteve]

Thanks for the reply all. While under the truck the other day I retouched every bolt, nut, heat shield and wiggled both drive lines to see. Nothing moved except for quite a bit of play in the rear diff pinion. Decide to jack the rear up to see exactly how bad the rotational, side-to-side, and in/out play the diff components had; I was able to replicate the jingle noise. Now that i think back, i replaced the diff fluid in the rear and around the same time I started hearing the noise soon after. The old fluid was basically a 50/50 mixture of water and gear oil (aka black/grey sludge). The gunk must have been thick enough to reduce any road noise and now that it has fresh oil its all loosey goosey. Time for a fresh rebuild.

Good excuse for a rear locker now!

Thanks for all the advice everyone!

 

[caladin]

Could it be the fork/lever that moves the throw out bearing. It's mostly inside the trans bell housing, and the clutch slave cylinder is touching one end.