When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Just noticed a small chip in the lower gear. Does this need replacing or just file the edge down a little? Not sure why only one tooth would have a chip in it. Hopefully, the cam gear is ok
.
Not sure where that piece is. The motor hasn't run for 26 years. I had the oil pan off and the oil pump out and I cleaned the screen so hopefully, it came out with the oil. Thanks
The middle of the gear is where the cam gear hits first and most.that very end probably never contacts the cam. Gear was either chipped by being dropped or that flaw was there since new. Also chip is on the back side of the gear. You can see the wear pattern on the gear teeth at the bottom of the pic.
Last edited by derekderek; 12-10-2018 at 08:58 PM.
The middle of the gear is where the cam gear hits first and most.that very end probably never contacts the cam. Gear was either chipped by being dropped or that flaw was there since new. Also chip is on the back side of the gear. You can see the wear pattern on the gear teeth at the bottom of the pic.
Think that arrow is pointing to the chip in the middle of the tooth bottom directly behind where the arrow ends
Last edited by Hammerhead Fred; 12-11-2018 at 11:19 AM.
DD is correct about location of wear pattern
Dist turns CW when viewed from above
Also when viewed from above, Dist is located just to passenger side of motor centerline
Cam turns CW when viewed from front of motor (same as crank)
what may be mistaken for chewed teeth may be encrusted old dried sludge on Non-thrust sides of teeth
-edit if that one chip is all, then I'd use gear maybe dress the chip with file or stone as others say. Otherwise, a new, correct gear is under $40 acdelco pn 10456413
Not that my opinion on this really matters..... but if it were in my shop it would get a new gear....only because I have replaced a few distributor gears over the past few decades that the teeth were really bad and the distributor would not turn. And if the owner wanted me to modify it...I would tell them do it themselves so if and when it failed...they had themselves to blame and not come back at me like I do not know what I am doing.... and forget all about me telling them they needed a new gear.
Let it blow apart and then you will be removing the oil pan to get the shrapnel out....and see the cost of a new gear is not that big of a deal.
As a guy that has seen bunches of these, it looks fine to me. That little chip is irrelevant. The wear surface looks fine.
If someone wanted a new gear, I would save that one for me.
I have seen them looking like razor blades. Bronze ones are good for shaving.
So if this missing metal of the gear is NOT in the wear area. How did it come off in the first place??? So...maybe it begins to further fracture and fall apart.... and pieces get into the gears of the oil pump and lock it up and THEN it really goes bad from there....which I have seen personally. I guess people can figure out how they would deal with this and I guess it is alright on however they deal with it. I know what I would do.
Not that my opinion on this really matters..... but if it were in my shop it would get a new gear....only because I have replaced a few distributor gears over the past few decades that the teeth were really bad and the distributor would not turn. And if the owner wanted me to modify it...I would tell them do it themselves so if and when it failed...they had themselves to blame and not come back at me like I do not know what I am doing.... and forget all about me telling them they needed a new gear.
Let it blow apart and then you will be removing the oil pan to get the shrapnel out....and see the cost of a new gear is not that big of a deal.
DUB
Really. How expensive can it be? It's easy and the distributor is already out. I would just replace it.
The gear appears to have had some handling damage PRIOR to final machining and hardening. You can see that the edge of the damaged ares shows no signs of breakage.
This is a NON-issue. (and still not in the 'wear area' of the cam worm drive gear).
Fair enough...then let it ride....simply due to only one photo and not being able to hold it in my hand and take my jewelers loupe to it...it might be just as you say. Still nonetheless... I would not feel good about putting it back in and due to the cost of a new gear is not an issue at all due to being so inexpensive....I would more than likely replace it. Others can do as they wish. And if this thread were that of a customer asking you opinions and information and you tell them to not replace it.. That customer then can sign off on it so I am not responsible for any problem if anything does happen with it.
Understand your concern, DUB. But there is more to see in that photo than I chose to detail...just for expedience. The gear has been in use for a substantial period of time (I assume). That being the case, there are two very telling clues which convince me that this was damage PRIOR to final machining and heat treat:
1. There are NO 'bright metal' worn areas at the edge of the missing material--which means that the damage was done BEFORE final machining.
2. The area of missing material is heat treated as evidenced by the same coloration of that area as at the ends of the teeth (bottom surface of gear at the teeth).
Further: At any one instant in time, there are at least 3 of those gear teeth which will be in contact with teeth on the cam drive gear. The bad area at the end of the damaged tooth will never see full-loading...it will be shared by the others. And if that tooth cannot provide any loading at that point in time, the other two can easily support that light amount of load.
I was concentrating in another area. The area with the BLUE circle was not what I was looking at.
I copied the photo and magnified it and what I THOUGHT I saw is not really how it looks.
The YELLOW circle is what I was looking at like a chip of metal came off the end of the tooth. When in reality...it really is not and it is more of an optical illusion at first glance. Ora t least that is what read into it.
As a guy that has seen bunches of these, it looks fine to me. That little chip is irrelevant. The wear surface looks fine.
If someone wanted a new gear, I would save that one for me.
I have seen them looking like razor blades. Bronze ones are good for shaving.
I see what you're saying DUB. The quality of the photo doesn't show it too clearly. Other than that chip that is circled in blue the rest of the teeth look really good. Looks like the gear will be ok as it was a defect during manufacturing as the other's have said. Now on to the next problem. At the top of the shaft, there is a splined area where the mechanical advance plate for the springs mount to. The top piece is able to pull down a very small distance, probably about 1/16th of an inch. I don't think it has moved from its original orientation on the splines but I am worried that it might come loose. I ran some high strength red lock tight around the area but it didn't work. I cleaned it again and put some more lock tight on it so hopefully, it will work this time. Is this top piece welded or just peened over on the top? I could hit it with the welder if that would lock it in but I don't want to do any damage to it with the heat. splined area
12-10-2018, 07:19 PM
chipped distributor lower gear
