From what I've seen this is very common. So what’s going on here.... Cam walking around, Poor machining, Bad metal?

 

IMO...its all about production and they make parts as cheap as possible

 

yes, it is common. a guy i know in Kentucky went to replace his leaky intake gaskets and when he pulled the distributor out, he noticed the gear had wear on it. so he replaced it along with the intake gaskets.... and it cured his misfire! im not sure why the gear is wearing out, but i bought a new gear from AC Delco it had a new part number that supercided the old part number. maybe the made revisions to it or improvements in order to give it a new part number.
just curious, when you replaced your gear, did you put a new shim washer, tang washer , and roll pin? also did you ever hook up a scanner under your dash to see if the timing was jumping around with the old gear? thanks so much

 

it could be lots of things causing it. it could be made out of cheap metal, or are using cheap motor oil that doesnt have enough ZDDP in it, or it doesnt get enough oil splashed on it while running, could be lots of things.
just curious, after you put in your new gear in , did you check to see how much play you have if any at all in the rotor by turning it left and right with this new gear?

 

resurrecting an old thread.

I'm not sure what initially cause my 2002 to eat the first distributor drive gear but now on my 4th and I can see that there is wear on the cam.

The distributor drive gear wear has been getting more frequent. I suspected that the cam may also have been damaged and confirmed it when I pulled the intake for a leak the other day.

Has anyone done an in-vehicle camshaft swap on a Blazer?
Does anyone have any other clever ideas on how to fix this??


I'm not really interested in P1345's, timing, relearns, retards and what not.

 

The only 'clever idea' is a step in which u claim to not be interested in! my advice is stock up on drive gears...lol.

 

I guess I deserve that. Sorry about the snippy post.


There are a lot of threads that start with "I just changed the dist drive gear and..." the timing is off or check engine light is on, etc. The threads then continue talking about how to set timing and whatnot but nothing about why the gear got chewed up in the first place.


I will probably have to stock up on drive gears because it now looks like the cam gear also has damage.

 

Usually the cause of excessive distributor gear wear is too much camshaft thrust clearance, especially in high mileage engines. . Another cause can be too little thrust clearance between the gear and distributor housing, along with marginal lubrication.

Try a GM melonized distributor gear, part #10456413

 

ive never seen the gears wear out, but ive seen the bearings wear out inside the distributor unless thats what you guys are talking about, they wear out so bad the rotor actually comes up into the cap and spins a big gouge all the way around it.

 

The I.D. of the intake manifold hole is larger than the O.D. of the distributor housing. If the distributor is not installed "plumb" with the camshaft, the distributor gear wears. Adjusting camshaft retard will cure the problem. If your check engine light is on, and P1345 is set, the distributor is not installed properly, guaranteed. However, even if P1345 is not present, camshaft retard could still be out of spec causing the gear to wear.