Re: \'72 J4000
This sounds like an excuse to ckeck/change all your drivetrain's gear oil. Check the diffs first. Good? Go to the T-15A 3-speed tranny to see if the fluid has schrapnel. If not, remove the Dana 20 t-case and see if you can turn either of the output shafts. (See/feel any metal shrapnel in the gear oil???) If not, consider having it rebuilt/replaced. IF everything is proper, check the clutch pack and the throwout bearing.