I got a 1988 f350 5 speed 96,000mi. I have a tick that goes with the RPM's. I've done replaced exhaust manifold gaskets, took the valve covers off ran the truck with them removed everything looked good. the noise seems to be the loudest under the truck by the bell housing can't really hear it under the hood. I removed the dust cover on the bellhousing springs look ok but there is about 3/4" play in flywheel. there is also a slight buzzing sound also. Is it possible for a DMF to make a constant ticking sound? it never changes clutch in or out, pulling or down shifting.