International jerky when taking off

My best guess here would be that the clutch disk, the flywheel, or one or more of the clutch plates is warped. When you engage the clutch, instead of making full smooth contact, it only contacts at part of the clutch facing, and causes the feel you get in the pedal. And we all have a human response to try to smooth it out with very small foot actions, and in fact it just worsens the problem. Someone, somewhere down the line probably had a pretty poor clutch technique and this is the root cause of the problem. In time, earlier than would normally be expected, the truck will need a clutch replacement, and a refacing of the flywheel. That should eliminate the problem.

It's possible that it could be something else, but that would be the first area I would look into. A mechanic may be able to see evidence of it through the adjustment plate for the clutch brake, but if not then the trans needs to be dropped and the flywheel checked with a straightedge.

 

I drove a couple of internationals like that it seems the engine torque rotates the engine and transmission like a broken motor mount. but it isn't broken the rubber mounts flex the engine and trans rotate to the left and the clutch pedal sinks . if you converted the clutch linkage too a cable or hydraulic, the problem would be gone.which is why some trucks have cable or hydrologic clutch linkage.

 

Around this neck of the woods the Int's are known for that , I drive one and have had many jerky starts when getting on a scale from a small incline,and as the original poster stated it seems to be worse with a heavy load. I've got a cummins under the hood as well.

 

Right heavier loads cause the engine and tranny to twist more.

 

Ever since I first read this thread I've been paying attention, when at the scales and it really does seem to me that the only Trucks that look like they are doing the "twist" are the Int's .