Designing a proper Gib Key Puller

As with all things, I think it pays dividends to collect data and study the problem until you are reasonably confident you have the complete picture of the mechanical forces, and what generally impedes the movement of the Gib Key when you attempt to extract it.

 If you talk to enough old timers, you will inventory a number of stories, you’ll learn about drill guides and their methods to hollow out a broken off Gib Keys, you’ll learn why the Gib Key head might have broken of in the first place. Your efforts to learn what the old timers knew BEFORE you proceed is critical. The OLD ENGINE crowd is an excellent group to learn from. 

One of the first steps is to break the rust bonds around the key and key way, get some penetrate in there, some swear by Kroil, others say kerosene is as good a penetrate as anything. At this time, I favor the Kroil.

 Time is your friend, allow some time for the penetrate to work.

If you research the Old Timers tricks, you will find one of them was to weld what is left of a gib key with a broken off head to the crank shaft, and then use a piece of alloy material such as aluminum to place on the flywheel hub, and gently nudge the flywheel to move inward and away from the key. There are other tricks, get one flywheel off, and you can extract the crank from the engine case with one flywheel still attached, and this may give you better access and additional options.

When you consider that the keyway in the flywheel is tapered, AND the Gib Key is Tapered, you will realize that the best Gib Key Puller is designed to push the Flywheel and Gib Key apart. It doesn’t matter if the flywheel moves .001” or the Gib Key, it’s all about getting either one to move that first .001 of an inch.

Sure, I’ve seen pullers designed to pull the key from the flywheel working off the end of the crank, it seems like such a good idea at first, but often the bond between the key and flywheel means that the force you are generating is doing less than half the work to separate the Gib Key from the Flywheel. This type of puller helps to pull the heads right off the Gib Key, and then you’re left to make a drill guide to hollow out the key and hopefully collapse it by generating a twisting force by locking one flywheel and rocking the other back and forth.

The design built for me by Robert Golighty is a superior idea over the puller mentioned above, it takes into account that movement of either the Flywheel or the Gib Key is our goal. Some would suggest that this is just plain common sense, but many just don’t get it till they pull a few Gib key heads off, it certainly won’t happen every time, but one time is usually more than the average mechanic wants to see.

 The Golighty puller has a collar that bolts around the Crankshaft, it grabs the key head close as possible to base of the key.  It has three jacking bolts that push against the hub and pries the key and flywheel apart.

 In my opinion, if you are investing in the Gib Key puller that leverages off the crank, go ahead and get yourself a drill guide and some drills long enough to work from the end of the crank at the same time, you might need them.

Of course this is my opinion, and there are others who may have a different opinion.       

All the best,

 George B.