Yesterday after pulling out of a parking lot and getting on the throttle and going through the gears, I started hearing a moderateley loud ticking/knocking sound. It increases with higher rpm's and is still noticible at idle. You can not hear it from under the hood, but it is pronounced inside the cab and under the vehicle. Sounds like it's coming from the transmission/bell housing area but I can't rule out bottom end of engine. When you push in the clutch, the noise is still present, but i also hear a grinding noise. Also, you can feel the knock in the shifter in all gears (nv4500). Any ideas, possibilities, things to check?

 

My guess would be the clutch or flex plate. Not sure how to check it without dropping the trans. The clutch in my jeep ticks and has a slight grind sound but when I press the clutch it stops. It has done it since the day I bought it 4 years ago.

 

I just crawled up underneath it with a mechanics stethoscope. Narrowed it down definitely to the rear main/clutch area. transmission gear box sounds smooth as does the bottom end of the engine for the most part. heard some very slight grindingish noises but i dont think it's anything out of the ordinary. The clutch in this truck is a south bend dual disc that the PO had installed last year. Assuming i pull the trans to find a worn clutch & bearings, what's a good replacement?

 

South bend is a good clutch. If it does turn out to be the clutch and you don't want to go back with SB check out Valair.

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You might want to drop the oil pan and check the rear main bearing. It is probably fine but just to be safe.

 

got the transmission and clutch pulled today. Only thing out of the ordinary I found was a nicked up bell housing, pressure plate, and a small chunk of metal that was determined to be one of the little round things that goes on each side of the flywheel inbetween the clutch discs (forgive me for not knowing the correct terminology). Also, once the transmission and clutch was removed, I started the truck. It ran for about 15 seconds then I shut it off. Any more ideas? here's some pics.

 

Was the noise gone when you ran it without the clutch in?

 

As far as I could tell, yes.

 

Do you have a picture of the piece of metal you found? That must've been your problem. I'm sure it was getting kicked around in the bell housing by the fly wheel judging from the way everything is scratched up.