Stripped Distributer Gear?

So has anybody ever stripped the distributer gear in a 4.0L motor?

Is there a better than stock replacement gear or distributer?

I have a 4.6L stroker so I figured I would ask here in the Modified Tech forum. So I was driving along today from a stop light getting onto a highway and was running the motor out to around 4k RPM and first gear it was fine then second gear right as i lifted the throttle to shift into 3rd I heard a huge pop and then lots of misfiring and then the motor died. I saw some smoke out the back and started to fear the worst. Once I got out and looked at the motor and saw that there where no holes or parts missing I tried to turn it over again and the motor spun free but sounded like the timing was off. Pulled the distributer out and saw the gear on the distributer was stripped. So now its sitting at the shop waiting to be fixed.

Thanks,
AARON

What makes you think you did - having timing trouble?

There are bronze gears available, and I tend to think they're better for two primary reasons...

1) They're softer than iron/steel, and won't cause excessive wear on the camshaft.
2) Bronze (especially sintered bronze and Oilite - and most bronze distributor gears are one or the other) tends to soak up oil, keep it fairly well-lubricated in low-load applications (like this.)

I've used bronze gears in SBChevvies, and haven't had any trouble. I'm not sure who carries them for our AMC242's, but I'm inclined to think Turbo City might. I think Accurate did, but they've folded...

5-90

Hesco stock the bronze dizzy drive gear but like everything else Hesco stocks, it's pricey. Might be worth the investment though.

I know that the gear is stripped. I pulled the distributer out when I was stranded on the side of the road and looked at it and saw no teeth on it. When the Jeep died it sounded like timing problems so that was the first thing to check. Plus the motor still spun over freely and nothing else inside sounded like it was broken. I dont really want to spend $76 for a bronze gear from Hesco since I need the Jeep up and running tomorrow so I can get back to school. Advanced Auto has a gear for $32 and I can get it first thing in the morning. I am going to drop the oil pan this afternoon and fish out any shavings then put in fresh oil and a filter and run it for a few hundred miles and drain it back out to hopefully catch any other particles.

5-90, the battery cable upgrade I got from you a few weeks back are absolutly fantastic! Thanks again.

Aaron

You're welcome - thanks for the kind words!

If your dizzy gear is stripped, at least check the cam side as well. It probably won't be stripped (it should be rather harder than the dizzy gear, which is easier to replace...) but you never know. The same logic on starter pinions might apply - the starter is easier to replace than the ring gear, so make the ring gear softer...

5-90

The cam gear is always much harder than the dizzy drive gear so it's highly unlikely that the cam gear teeth are worn but you never know. The dizzy drive gear is usually designed to be the sacrificial gear 'cause it's a lot easier to replace than a cam.
Since you're going to drop the oil pan anyway Aaron, you might as well inspect the cam gear while you're there just to be sure.
There's a remote possibility that your cam could be "walking" backwards and forwards so you might wanna check that out too. This can only happen if either the thrust pin/spring assembly isn't put into the cam bolt during assembly or if the pin wears out.

Dr. Dyno said:

The cam gear is always much harder than the dizzy drive gear so it's highly unlikely that the cam gear teeth are worn but you never know. The dizzy drive gear is usually designed to be the sacrificial gear 'cause it's a lot easier to replace than a cam.

Click to expand...

No argument at all - that's the way I'd do it. But, it seems that normal rules of logic do not always apply once you get accountants and lawyers involved in engineering decisions.

I forgot who said this originally (Mickey Thompson, perhaps?) but it seems to be forgotten that "I am the engineer, you are the accountant. Your job is to keep track of my beans, not tell me what to do with them!"

There really is no quicker way to screw up good practical engineering than to involve some damn accountant or some damn lawyer - it may be easier to heat-treat the pinion gear on the starter, but it's also far easier to replace the thing, and the ring gear should have been heat-treated... Do you have any idea how many ring gears I've had to replace, while the drive pinion was still pristine?

5-90

I didnt end up dropping the pan. After draining the oil and inspecting the dizzy gear, all the particles came out in the oil. I washed down the inside of the pan through the drain hole and oil temp sensor hole with brake cleaner and what ran out was clean. I only hope that the oil filter did its job and filtered out all the really fine particles since there wherent any big pieces in the bottom of the pan. The cam gear looked great when I looked at it with a flashlight. A good old family friend mechanic said that Chrysler engines are notorious for eating distributer gears. He has had all sorts of problems with his 318, 360, and 440 motors wearing the gears out in addition to hearing about Jeep motors spitting them out. Its been his experiance that the heat and age are what mostly contributes to the failure of the gear but also gear wear can be caused by a walking cam like Dino suggested and also heavy use. It will be put on the list of things to check every so often for maintence from now on.

AARON

Some aftermarket cams have an affinity for iron drive gears...using a high pressure/volume oil pump is a major contributor too...if the thrust button is damaged and the cam is walking...a timing light will show the scatter.