Camshaft Diz Gear - Too Much Wear?

[NO6YHY]

I bought a set of matching camshaft and distributor gears from Bulltear about 10 years ago. Only driven about 5,000 miles on it, with periods of sitting. Anyway, replacing my camshaft and noticed this. Does not look good. Any guess as to what the problem could be? The distributor gear actually looks pretty good, just light rubbing. Prior to putting these on, I had worn out my previous distributor gear, camshaft gear looked fine. Worried about not getting enough oil or if there is some kind of camshaft play that could be causing this.

All input appreciated.

[Chevelleguy]

Did you make sure that the oiling hole in the cam timing gear is lined up correctly? I've seen worse on a high mileage engine, but that's pretty bad for only 5K miles.

[TexasJ10]

Are you using a stock timing gear cover with the locating pins? It looks like the to gears might be misaligned.

[NO6YHY]

I will double check the oiling hole. Yes, stock timing cover. Before I installed it last time I lapped it a little with 400 grit on glass to make sure it was dead flat, don't think it took off very much material though.

What boggles my mind is that a new set of these gears from MSD costs as much as a new cam, and more than a timing chain/gear set. I guess there is no cheaper source???

[babywag]

I've never had a problem using good original used ones.

[bkilby]

Some good oil mod advice. I had to open the groove in my cam timing gear as the groove was mostly closed (#2).

https://www.msdperformance.com/support/troubleshooting_techniques/#AMCModify

[SC/397]

Have you been using a Zinc additive in the oil?

[NO6YHY]

Have you been using a Zinc additive in the oil?

I haven't. Never occurred to me that the rig needed anything more than plain motor oil. Now I read about racing oil having more zinc, but apparently it's bad for catalytic converters. So not sure what to do.

That link bkilby posted was great, going to go through it and make sure that all the passageways are open.

Also, I went ahead and ordered the Crown replacement for $29. I'm sure the MSD set is better at $105 but I couldn't see paying that much, especially when this set cost $80 and was nothing special. Going to put some assembly lube on and see if that helps break them in better.

[SC/397]

I would check the Crown one every so often as well. I have had one last only about 15 miles. This was a while back when they first took the Zinc out of the oil. I try to use old OE ones when I can. Hopefully, your oil filter caught all of the metal that got worn off of the gear.

[440sixpack]

MSD is worth the money .

Unless you're running roller lifters zinc is a must, damage to your timing gears is only the start of the problems you'll encounter without it.

There are lots of options to get the zinc you need , Brad Penn brand oil is the one I've used in all my flat tappet engines for some time and I've had no issues.

[FSJunkie]

Distributor gear shouldn't care about ZDDP.

Often times AMC V8's eat distributor gears because the slot on the backside of the timing gear doesn't line up to the oil hole in the camshaft that feeds oil to the distributor gear. Reduced or no oil flow is the result.

You always have to check the timing gears on these for alignment and widen the slot with a grinder if needed.

[Ristow]

i've broke in a lotta AMC's,a lotta cams. more than most. never crashed a cam,never ate up a set of gears,save for a chinese distributor. never ran fancy oils.

that crown gear is junk. wasted money.

[440sixpack]

In low performance engines running mild cams and light springs you might get away with it if you're lucky. but even at that they were designed to have zinc in the oil.

If you ever wanted an example of cheap insurance running zinc all the time is it. I cannot imagine breaking an engine in without extra amounts of zinc.

[FSJunkie]

ZDDP is for high-pressure, high-heat surfaces. The heat and pressure activate the Phosphorus.

Distributor gears are none of that. They're a cool-running sliding contact surface with little pressure. ZDDP does not matter on the distributor gears.

Cam gear misalignment does. Oil that is too thick does. Seems like everyone insists on running 10W40 and 20W50 all winter on this forum, and that is a great way to simultaneously reduce oil flow to the distributor gears AND increase the load on them.

[Ristow]

i aint saying the zinc isn't good,i'm saying i cant recall anyone having cam or other wear issues and the oil being problem.

historically here when guys are having issues like cam/lifter wear its because they didn't verify lifter preload,or the springs are binding,or they cranked the motor over for half an hour while they played with the distributor trying to get it to fire.

the above gears have an oil flow problem,or are turning more than they should due to some actual reason. possible cam walking due to a lobe wearing out.

yah,the heavy oil might make the gauge look better,but its at cost of flow.