Originally Posted by Jeremy5848

There's a ball bearing that, in the earlier models, does not have a caged race. If the bearing comes apart, the balls and such can drop out and end up jammed in the timing chain, causing it to break. That stops the camshaft and leaves one or more valves open, which, since diesels are interference engines, causes one or more pistons to smash into the valves.

In the latest units, the ball bearing is sealed and should not be able to spill its guts into the engine. Apparently there's no way to tell when the bearing is ready to go.

Jeremy