Bad Timing Gear?

oriondal

oriondal

Junior Member
Hi guys,
I was driving the A and it started knocking a bit then quit and wouldn't restart. A quick inspection show the distributor rotor wasn't turning. I removed it and the lower distributor shaft, and the gear at the bottom isn't turning with the engine. Does this sound like it might be a bad timing gear? I haven't had the chance to remove the valve chamber cover, but I guess that's the next step. If it turns out to be the timing gear, I see they sell both aluminum and fiber gears with the fiber available in standard, .03 oversized and .05 oversized. They're all about $50, any suggestions which might work best?
Thanks
 
Metal gears will likely last a lifetime. I've never got long service with the fiber gears. Replacing timing gears is a real pain. I only use bronze or aluminum and either one runs quiet for me.
 
You don't need to remove the valve cover, but you need to remove the front and side timing gear covers. Just stick the timing pin in it's hole and hand crank the engine and you'll know if the timing gear is turning.
 
Yep, sounds like the timing gear. Try the timing pin per Tom. Otherwise pull the side cover. Two bolts and the pan bolts on the underside. Easy enough to do. Then you can see the gear directly.
 
Yes, it does sound like a failed timing gear. Either the teeth have sheared off or it may have failed in the center where the aluminum hub attaches to the fiber gear outer section.

Look at the old gear and see if it is marked as "oversize". If it is, go with the same oversize and if not, stay with a standard sized gear. A "pinched" gear due to too much oversize won't last long.

Metal or fiber is your choice. Usually with an older engine, fiber is recommended as metal gears may be a bit noisy if mismatched due to not being replaced as a set.

John
 
Update: I removed the timing side and front covers and tapped the original style nut loose with a chisel (didn't take too much effort). I removed the timing gear which was fiber and missing about 11 teeth. The crankshaft gear showed no wear. I've order an aluminum timing gear and modern hex nut along with several gaskets. I'll replace the timing gear, clean out the oil pan, reassemble, retime and give it a try.
Thanks all for your help.
Dale
 
Thats exactly the way that I would have done it. When you replace the gears and align the timing marks , it won't be necessary to retime the distributor. If the distributor timing was correct before , it will remain correct.
 
Is best if you replace crank gear and new aluminum timing gear as a matched set . If not there will be some metal wear off the new timing gear as it fits into the crank gear . This metal ends up in the oil which could end up in the bearings . Local engine re-builder only uses match set of metal gears, if not, uses one piece fiber gear when replacing timing gear only .
 
Maybe. Matching may not be that important. If you do not have the proper KR Wilson tool to get the crank pulley off in the car better wait until the engine is out before you damage something.

Since the car has no oil filter, metal ends up in the oil all the time. Which is why I put a filter on mine.
 
Another suggestion I would make is to consider cleaning out the pan. Where are the sheared off fiber teeth? the oil pump screen may have several. I happened on a guy headed home from a large meet in 1998 and He had just finished replacing the timing gear at a turnout on highway 80. He used my free oil to replace the crankcase oil. the motor didn't make it back to LA. I blame that on stuff floating around in the motor after the partial repair he did. Quick but incomplete repairs can lead to more serious repairs later.
Bob
 
the pin in the oil pump dist. drive gear sleeve could have broken or fell out,this would cause the dist. shaft not to turn.
 
rocket1 said:
the pin in the oil pump dist. drive gear sleeve could have broken or fell out,this would cause the dist. shaft not to turn.
Click to expand...


I may be wrong but I don't think a broken pin would stop the
distributor from turning, it just holds the sleeve in place.

Bob
 
Bob C is right about the pin. If teeth are stripped off the cam gear, removing the oil pan and clean out is a must.
 
A belated update. I replaced the timing gear with a metal one, removed, cleaned and replaced the oil pan and put everything back together. It runs like a charm, but leaks some oil when running. I think it's coming from around the rope gasket at the front of the crankshaft, so I'm going to have to go back in there and see what I can figure out.
Thanks for all your suggestions.
 
With the 2 to 1 gear reduction, Dave's wifey held the crank while he torqued the cam nut to 105 Ft Lbs toque!!! I told him he'd better not pick a FIGHT with MARLA!!!-Bill W.
 
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