NV4500 noise in fourth and fifth
 

I've got a stock 98 12 valve 2500 2wd that I just replaced the clutch in.

Since the replacement Ive had a tingling noise (something, but not exactly, like the sound of a bad bearing) when in forth and fifth gears. There is no noise at all (regardless of speed or rpm) in first through third. As soon as I get it into forth it starts. There is no noise in neutral until I hit fourth gear then the noise is the same in forth, fifth and neutral. The noise has no discernable volume or frequency change regardless of speed, rpm, whether it is in fourth, fifth, neutral or whether the clutch is engaged or disengaged. The noise goes away immediately upon downshifting into third or when dropping below approx 30km/hr if in neutral. Oil level is good.

I'm hoping that the experience here can point me in the right direction.

Thanks in advance for any help.

check your pilot bearing in the flywheel. I had that same thing happen to me when I put my new clutch in. for some reason the input shaft pushed the pilot deeper into the flywheel and it wasn't engaged on the input shaft. dont know why it did it. had to take it all back apart to fix it what a p.i.t.a. after I got that right it sounds like a new truck. Hope this helps. Good luck