I blew a clutch bell way back..( mounts moved) was not aware until truck was pulled.. so it wore the spur as well.. ran for about 1/2 gal until new spur arrived.. was LOUD when it was worn.. .. once replaced is quiet..
my thoughts if you have noise. something is wrong somewhere.. i also shim my diffs.. you may have a skipping ring gear: )
too many things to guess at.. but you may have gear mesh a little tight on the bell and spur.. best to invesitigate
