Distributor problems

-
Ron Grubb

Ron Grubb

Member
Joined
Mar 16, 2021
Messages
21
Reaction score
1
Location
Indiana
What on earth would cause a distributor to fail at the base of the shaft? See pic. Car had not been started in years. IT turn over easy… pulled plugs… put some light lubricant in cylinders turned over by hand several times each day for over a week. Changed oil and filter. Finally tried to start. It ran for about 10 seconds then stopped. The distributor had twisted so much it apparently snapped the lower section off. And totally cracked the distributor cap in half. Is it bad distributor or a larger issue inside the engine? The rotor turned like normal when I was rotating engine by hand.
7E472D99-623E-4936-8306-E3DAB9067685.jpeg
 
What engine? Did you pull and inspect the oil pump shaft ? Was the pump rotating? Debris in the shaft and cam gears?
 
Last edited:
What engine are you dealing with?
Does sound like a strange problem.
I snapped a intermediate shaft before, but I think that was do to a lot of water in the oil. Engine sat for a lot of years and I was trying to turn it over.

Small block 340 was what I was working on at the time.
 
I'd say the shaft tried to seize in the distributor bushings, and or some mechanical problem tried to "stop" the mechanical advance mechanism. Unless that action damaged the intermediate gear, and it might have, I'd say the problem started and ended at/ in the distributor
 
looks like the rotor jammed up the works, but it's hard to imagine it was stronger than the drive-lug. What about a foreign object under the cap?
It's hard to figure that it ran for 10 seconds tho before it snapped, unless it was maybe partially broken from the get-go.
Maybe it seized in the lower bushing, but that doesn't explain the busted cap.... maybe you are dealing with multiple problems. hmmmmmmmm

just guessing, I am.
 
Last edited:
Need more photos...

My guess is the dist shaft was 90% sized when you rotated it by hand. Spinning the engine at speed and it siezed the rest of the way, snapped the drive lug. As for the dist cap...

Maybe the dist shaft pushed up enough to shove the rotor through the cap.

Just a lot of guessing without more photos.
 
ve seen that the shaft is/was full of baked on grease/oil and it was hatd to rotate, then the top of the shaft is probably bent and it hit the cap. That tab on the bottom is designed to sheere off to shut the motor down just because of this.
 
I've see that twice both times it was the distributor cap. One was a new mopar mechanical advance with a tach drive. Both times the cap mounting was the issue because one had a broken rotor and the other a broken cap.
 
I've seen the wrong cap or rotor do it, a bent upper part of the lower shaft (the one the upper section mounts on), seized bushings do it, but, the most common is when someone drops a points (or pickup) screw down into the distributor, and just gets another screw instead of fishing out the dropped one.
 
Either way, you're looking at getting another distributor or a serious repair on that one. Just remember to remove the broken tab from the driveshaft slot with a magnet.
 
cudamark said:
the most common is when someone drops a points (or pickup) screw down into the distributor, and just gets another screw instead of fishing out the dropped one.
Click to expand...
Very true it happened to me, trying to get a car going, and found this. Nothing broken but advance would not operate.

IMG_4128.JPG
 
I would jusyt scrap that distributor, for the price of the shaft and bushings prob be cheaper to source another one with the right curve unless it is a $$ dual point or a points car.
 
Last edited:
You must log in or register to reply here.
-

Back
Top