Jerrys Old Engines in South Africa

How to make a Gibkey puller from scrap. (4th May 2007).

(This article was published in Gas Engine Magazine - Oct/Nov 2007 issue.)
 

Removing a Gibkey, especially those really old stubborn ones, has been a topic of discussion on the engine lists many times and there are many ways of approaching the problem. They all involve 1) Loosening the key (which is probably seized tight) by various means including heat, penetrating oils and solvents and, 2) removing the key with either a wedge and hammer or a puller of sorts or a "percussion/impact/slide hammer" to "shock" it loose . Of course, if all else fails, you can drill it out.

I had the problem that my little Ruston & Hornsby PT was leaking oil from the timing gear cover and the 2 bolts (1/4" countersunk machine screws) that needed to be tightened were directly behind the flywheel rim with no way of reaching them with any kind of tool. The flywheel would have to come off.

I only restored this engine 2 years ago so I knew that the gibkey would not be too tight or rusted and would be a simple matter to remove but I was loathe to use a wedge or any method that involved pressure against the flywheel as this could damage the paintwork. He is, after all, a really handsome little chap and has a great paint job even if I say so myself :-). Click here to see him.

The design I came up with is very simple and can be made by anyone with very basic tools (welder, files, drill press and hacksaw - a lathe is a great help but not essential). The materials all came from my "scrap box" - see Pic 1.

I have not put sizes to my drawing for obvious reasons. This one was made for my Ruston and will also work on my Wolseley engines - crankshaft diameter 32mm to 38mm. Just remember that the inner diameter of Ring "A" must be big enough to fit over the crankshaft + the height of the key (not the key's head - the slot fits over that). The 2 adjusting bolts align everything for a grip on the gib head and a straight pull. Remember also that the "big bolt" that exerts the pressure will work best with a fine thread - and don't forget to oil it before use. The tool is robust enough to take a hammer blow to shock the key loose but also strong enough to exert steady pressure for a more gentle release. (Of course this depends on the materials you use as well as your welding skills).

   Since making and using this one I've had ideas for improvements. One is to make a "universal puller" ie. "one size fits all". This would be easily made by not welding the front ring "A" in place. Instead just cut a slot through the "pipe" to allow insertion of a piece of bar stock and a means of holding it in place to grip the gibkey head - I've included a rough sketch at the end. Any ideas for improvement will be graciously accepted.

I'm not trying to re-invent the wheel here, remember that my initial idea was just to make a puller that would not damage the paintwork on an "already restored" engine but this puller does seem to have great possibilities.

I do realise that this puller is not the answer to every Gibkey problem. There has to be enough space between the head of the key and the flywheel to insert the tool (I've got a Bradford engine here that has the head hammered right up against the flywheel and will probably have to try and knock the flywhweel back a bit - there is space). Also, if the Gib head has broken off there are other problems but this tool would be able to "grip" a welding bead on the end of the key. At the "end of the day" this puller will do a great job in most cases but you will still have to "loosen" a stuck key with penetrants or heat. I think that this tool - if constructed strongly enough - will also break the head off a gibkey that is really stuck so just use your head and be careful. It will certainly work better than a wedge and will do less damage to the surrounding old iron!


Update 31 August 2009 - a similar puller made for a special job. Click Here


Here are the pictures

Click on any pic to see a larger version - use your "back" button to return


I found all these bits 'n pieces in my various junk boxes. The pieces I eventually used are marked in the picture.
The 2" gun barrel probably came from an "anti-aircraft" gun and possibly has something to do with South Africa's dark past. I have no idea where I got it from but it had been in the junkbox for years :-) (Note: any piece of pipe could be used - it does not have to be a "gun barrel") :-)
The "Big Nut" eventually became the "Spacer" shown in the drawing below.

Scrap bits 'n pieces use to make a gib key puller
Plan for a gibkey puller made from scrap
This is a drawing I made after making the Gibkey puller. The drawing took longer to do than the actual tool took to make.
Note that a few details are missing from the drawing but become self explanatory when looking at the photographs.

This is the finished Gibkey puller. Not a work of art but very functional and robust enough for those stubborn keys that need to be tensioned and then given a hard blow with a F.B.H. (Very Big Hammer) :-)
Note the slot cut into the end - this allows the tool to be slipped over the head of the Gibkey - the tool is then rotated by 180 degrees for the Ring "A" to seat behind the head of the Gib Key. The 2 cap screws are then tightened by hand to align the puller to the shaft and seat the ring snugly behind the head of the Gib key.

Home made Gib Key Puller
Gib Key puller from scrap materials
Another view. Although strongly constructed, remember that it is usually necessary to loosen the key first. Use penetrating oils, heat or whatever your preference.
Although unlikely, this tool is strong enough to break the head off a gib key that is really stuck tight.

This pic shows how the tool is placed over the head of the Gib Key. The cutout slot in the face of the tool is slipped over the head of the key and then the whole tool is rotated by 180 degrees. The adjusting cap screws are then tightened (only finger tight) to align the puller to the shaft and seat the tool onto the gib key head.
Fitting the gib key puller
Gib Key puller - ready for removal of key
This shows the tool in position and ready to remove the gib key.
This drawing shows possible improvements for making the puller into a "Universal" type puller to fit different shaft sizes. The tube could be a bigger diameter and instead of welding the ring "A" (shown above) into place, a slot could be cut into the tube and a bolt fitted to hold a piece of bar stock into the slot  and make it into an adjustable puller.
Improved design Gibkey puller

Anti Spam Harvesting address picture

Click here to return to my front page