Sheared distributor gear on '97 5.7

[Dave Aley]

My nephew was driving my '97 dually a couple of weeks ago when it suddenly died. He pulled off the side of the interstate and called me, and I called a wrecker and had it towed to the shop. They just called me to say that they found that the distributor gear had sheared off.

For several months the truck has been running a little roughly, missing between 2000 and 3000 rpm, without throwing any codes. I've mostly been driving it around town where it doesn't spend much time in that range, so other than putting new plugs, wires, cap and rotor on it I've mostly been ignoring it. I had unplugged the EGR motor, which caused an EGR pintle position code but smoothed it out, leading me to suspect that the timing might be off. Research online came up with a few people who'd had similar symptoms caused by worn distributor gears, so that was something on my list to check, but again I hadn't gotten to it yet.

I'm surprised it had gotten to the point that the gear sheared, though. Has anybody else had this issue? I wonder if GM had a bad batch of gears.

Also, is there anything else I should be doing? I'm guessing an oil change is in order, at a minimum.