Have a 78FJ40. Year ago put in brand new rebuilt 2F and mated a FJ60 new 5spd trans - completed by my local shop. Engine has been vibrating and pinging and rattling since. Mechanics now seem stumped but think the clutch burnt out due to me shifting 2-3K miles on the new trans. They want to replace the clutch before looking into other diagnostics for the vibration. This truck has been through a $55,000 war after buying it “restored” - a lot of that’s on me for not doing my research and first having a full inspection done firstly. Love the truck - can’t afford to sell it now anyway! My mechanics are telling me that only a new flywheel will do. Which we know doesn’t it exist. They don’t seem willing to machine a decent shapes flywheel which has me confused - that without a flywheel the shifting / clutch is somehow better? I guess I’m looking to be educated on the conflicting views on new or machined flywheel or NO flywheel. I think I’m right to say “new” isn’t an option but I don’t have the background to know if my mechanic would have any reason in leading me one way or the other. Thanks and sorry for the long note.