IT FINALLY HAPPENED TO ME(dizzy gear wear)

[mrtazwrench]

We left the kids next door at My dad's to go to the polls, and I had some recycling to go down town also 8 miles round trip, well we made it almost 4 miles coasting down hill to a stop sign, backfired a coupple times, shot out some flame, I pretty much figured right away it had munched a gear. I confirmed that after my nephew came with my other J20 to drag us home, pulled the dizzy, the gear on the dizzy is toast, looked as if the cam gear may be OK. I may slam in a spare dizzy to drive it the rest of the way in the shop.

Now what I have done to this motor, it has 71,200 orig. miles on it now, I had the timing cover off for a leak, found slack in the timing chain, replaced it with the Edelbrock full roller, and put in a midplate, still had the stock cam, and stock dizzy gears. Since I put it back together oil pressure has been good, not high or low, only odd thing is after the first few days it had a little tick, sounded like lifter, had oil in it with break-in lube in it yet, changed it and it was nice and quiet, the last coupple times I drove it before this I thought I could hear a dull tick but not all the time, it has 1-2K on it since reassembly.

I will be going through all the dizzy gear tech, but looking for input on what has been done to this motor.

[AMX69PHATTY]

Wonder if the dizzy oiling features / passages in the Timing set are properly oiling the dizzy gears ?

[jeepsr4ever]

Put the tip of a felt marker in the oiling hole in the cam and install the large timing gear again. I am willing to be it is because of the lack of lubrication from a oil slot that is off.

[mrtazwrench]

Put the tip of a felt marker in the oiling hole in the cam and install the large timing gear again. I am willing to be it is because of the lack of lubrication from a oil slot that is off.

That will be the main thing I check, after reading through the dizzy gear sticky, I see some other alignmet of oil passages I could have messed up. I've been wrenching for 20+ years, 15 or so for a living, but never had one of these in for a chain, I suspect issues with the timing set as long as I have been doing this I automatically look fo all the little clues that tell me how things had been assembled.

[jeepsr4ever]

Another issue is that if the oil slot goes past the OD of the first bearing journal you will bleed off oil. This is an issue witht he newer Edelbrock timing gears for an AMC.

[mrtazwrench]

Another issue is that if the oil slot goes past the OD of the first bearing journal you will bleed off oil. This is an issue witht he newer Edelbrock timing gears for an AMC.

OK I can see opening up a slot that does not align, but what would I do about this? I recall this gear having several slots, I figured it was to set different cam timing.

[mrtazwrench]

Droped a spare dizzy in it and got it parked in the shop, I did not get it torn down yet, but the spare I put in came from a motor that was abused, I think had oiling problems and clattered the last time running, anyway that one was starting to wear the same way indicating I do indeed have an oiling issue with it.

[msalaba]

I had a 73 CJ5 w/ 304. I upgraded the points dizzy to the later Duraspark seup. I did not know at the time that you needed to keep the gears as a set. Of course the gears lunched after a mile. So, I changed the gear on the dizzy and go for another drive. Yup, lunched in a mile again.

After finding this site I learned that you replace as a set.
(Another great difference from chebby)

I changed the oil & oil filter after each failure. It was too late. The shavings got into the crank bearings. I noticed because my oil pressure went to 1psi @ idle and 20 psi @ 3500.

I pulled the pan off. It was full of shavings. Pulled the oil pump apart. It was scored and the pump housing was pretty well grooved.

My advise would be to make sure you clean teh shavings out of the pan, pickup and oil pump before running this engine again. I ended up replacing mine for a 360.

[mrtazwrench]

I had thoughts of pulling the pan as well, guess I'll be sure to now.

[mrtazwrench]

Another issue is that if the oil slot goes past the OD of the first bearing journal you will bleed off oil. This is an issue witht he newer Edelbrock timing gears for an AMC.

DING DING DNIG! We have a winner sure enough the slot goes too far out on the rear surface next to the cam. Now what do I do? contact edelbrock and ask what are you going to do about it?