My Willys 3A and 3B Community

3A, 3B, DJ Technical Knowledge Base => "Original"-- Technical Questions, Answers, Observations => Topic started by: AZJeepNut on June 17, 2013, 02:46:56 PM

Title: Timing Gear - old vs. new
Post by: AZJeepNut on June 17, 2013, 02:46:56 PM
The rebuild kit bought by the shop that did the machine work on my engine included new timing gears. I intended to use the new gears, but this morning I noticed that the new crankshaft gear was not drilled and tapped for a gear puller like my old one is. Now that I'm looking closely at the old gear I see what looks like a hairline crack running from a corner of the key slot toward the edge of the gear. I've checked several parts vendors and only one so far has the "original" drilled/tapped style gear, cost app. $65 +SH.

So, the questions are:

1. does that look like a crack and is that a common location for such?

2. should I just take the new gear to the shop and have it drilled/tapped like the old one?
Title: Re: Timing Gear - old vs. new
Post by: 1955CJ-5 on June 17, 2013, 07:05:00 PM
The shop probably could magnaflux it to check for a crack.

About the holes for a puller...I was just at the shop today and didn't notice that the new gear was different, until you made mention of it...but the old one certainly had holes, and the new one doesn't...



Title: Re: Timing Gear - old vs. new
Post by: AZJeepNut on June 17, 2013, 10:33:49 PM
On closer inspection I think the old gear needs to become a paperweight. What looks like a crack feels like a crack and now I see that  there is a chunk of steel missing in the opposite corner of the key slot. Looks like the gear may have been driven hard onto the shaft while the key was rocking on debris in the shaft slot. If the gear is driven onto the shaft while the key is unable to bottom out in the shaft slot I suppose that it would only take a few thousandths of extra key height to damage the gear. Either that or maybe a too large key. Guess I'll double check before I install the gear!

Too bad the replacement gears are not made with the tapped puller holes, but if you've got a good drill press and the right tap you can add that feature yourself without much trouble. Lacking both I'll take it to the shop and let them turn my "new" gear into an "old" gear.
Title: Re: Timing Gear - old vs. new
Post by: 1955CJ-5 on June 17, 2013, 10:51:46 PM
Good idea...I think that it is too late for my new gear to become an old gear...

You might be able to use the old gear as a guide in drilling the new one....

Old jeeps are great providers of paperweights...