Distributor gear question

My little bronco quit running about 2 weeks ago, thought a coil went bad due to no spark. Turns out, rotor was not going around, found 3 teeth sheared off the dist. gear. It appears to be a stock, cast gear on my MSD dist. the small block has a hyd roller cam in it. I'm 99% sure it needs a bronze or steel gear on it. Which one should I use?
btw-the wear pattern is very even on the gear and the cam gear looks fine.

I think the first thing you need to do is to put a socket and extension on the oil pump drive shaft to see if the oil pump has locked up. Most of the time when a small block oil pump locks up, it will "corkscrew" the oil pump drive shaft, but they've been known to twist the shaft and shear the teeth on the distributor gear. At any rate, I think you're going to be digging deeper than just replacing the gear. Let us know what you find.

Wayne (SAWDOFF) Pearce

X2 on what Wayne said... I caught mine in time while freshening up my small block years ago... When I pulled it apart, I noticed the oil pump driveshaft was twisted... At first, I thought it looked cool until we checked the pump and it almost wouldn't turn... Good luck and let us know what you find...






Doug...

These guys are right. Small blocks have a bad habit of seizing pumps and twisting shafts. If your pump has seized, you're probably lucky that the dist. gear gave up, otherwise it could've kept running and eaten itself up with no oil p.s.i.. Count your blessings.

Well, looks like I must be living good. Spun the pump on the drill today, made preassure and held it, seems like the pump is fine. Really looked over the dizzy gear and I don't think it sheared the teeth off, it looks like it just wore them off. I'll try to get some pics, if for no other reason than to show someone that doesn't understand why they need a steel or bronze gear for a roller cam.

If the teeth on the distributor gear are sharp enough to shave with, then that's a sign of imcompatible materials. If the dist. gear teeth are worn sharp, then you need to check the teeth on the camshaft. It's most likely toast also.

Charlie

prosandguy wrote:Well, looks like I must be living good. Spun the pump on the drill today, made preassure and held it, seems like the pump is fine. Really looked over the dizzy gear and I don't think it sheared the teeth off, it looks like it just wore them off. I'll try to get some pics, if for no other reason than to show someone that doesn't understand why they need a steel or bronze gear for a roller cam.

Might be a good idea to pull the front cover and make sure there is nothing (worn pieces of gear) anywhere near the chain... I went through this several months back when an oil pump locked up, and it wasn't pretty after the pump and shaft were replaced and then refired.

prosandguy wrote: the small block has a hyd roller cam in it. I'm 99% sure it needs a bronze or steel gear on it. Which one should I use?

.....steel


As Charlie stated, the cast iron dizzy gear was softer than the steel cam.