Lister D broken gib key

Hi folks, I have a Lister D where the gib key is broken off (not guilty it wasn't me) the engine was partially dismantled when I got it. The previous owner has try to drill the key out and knocked ten bells out of the flywheel. I have tried heat and lubricant to no avail. How far does the key go into the flywheel? I wondered if I could knock it through or will it go even tighter. Sorry for all the questions but I am sure I will have more. I look forward to your help. All the best, Norman

Norman,
A gib-head key is tapered so if you knock it in further you will make the problem worse. When the key bed was cut there will be a 'ramp' at the far end so not only will you tighten the taper but it could start to jam up the ramp. I think you need a puller and heat and release fluid but just a little at a time, easing back occasionally. Its a common problem. Failing that, as the flywheel/crank is 'overhung' you could remove crank and flywheel as one assembly and work on it separate from the engine itself.
Eric

Hi Eric, Many thanks for the reply, I had thought about a puller but that would be some puller! I read somewhere about using a press to release it but I don't have either. I have three of these to do and the only reason I started on this one was it was partially dismantled by someone who had obviously given up after breaking the key. A baptism of fire I think. I will see if a suitable puller can be purchased at reasonable cost failing that I may need to remove the whole thing as suggested. Norman

Norman, Puller is only as a last resort and then in conjunction with heat, allowing it to cool in between pull attempts. You may be lucky.....but be careful.
E

Yes, I am going to try and drill it out, unfortunately someone has been there before me and it a bit of a mess. When I get the flywheel off I will probably need to built weld up on the crankshaft and file it back to shape. Hey ho the joys of looking at old stuff. Norman

At the risk of getting boring !!   - Propane, Plusgas and patience. Apply daily and keep tapping / rocking.
I've also tried drilling and tapping to insert a bolt but with no success.
Good luck.

If you take the crank out, with the fact the key has been drilled, I would be tempted to set the flywheel across 2 boards or something solid and obviously taking care not to damage the crank end, try driving the crank through the flywheel taking flywheel and key of together, a degree of care is needed and I am not saying go at it with a fore hammer, but with penetrating fluid it might be enough to get things moving, once you get movement as has been said before, its on a bit, off a bit until you get it free.

That's just another option if your stuck, should you bell the crank a light rub with a file will allow the flywheel to pass.

That might be a bit rough for some here, I have done it in the past with success,

Chris

Many thanks for the suggestions, I will give it some thought and see the best way forward. I usually would attack it with a big hammer but will show restraint. I will need to get plusgas, I remember my Dad always swore by it, I didn't think it was still available. Norman

Norman Raeburn wrote:Many thanks for the suggestions, I will give it some thought and see the best way forward. I usually would attack it with a big hammer but will show restraint. I will need to get plusgas, I remember my Dad always swore by it, I didn't think it was still available. Norman

Plusgas is a proper penetrating fluid unlike WD40 which sometimes gets recommended, you could also try making your own from a 50/50 mix of ATF & Acetone.

The description of WD40 is in the first two letters, WD = Water Displacement, the 40 is the 40th attempt at creating the product.

MaryAlice

maryalice wrote:The description of WD40 is in the first two letters, WD = Water Displacement, the 40 is the 40th attempt at creating the product.

MaryAlice

Yet some folks still advise spraying it on rusty fasteners to free them off

Watching with interest, I also have a snapped off gib key on my Pb.

A few years ago I had a Lister A with the key cut off flush with flywheel.I tried drilling and taping a thread screwing a bolt in and pulling out with a slide hammer.It did not work so I drilled the  key to weaken it attached a puller to the flywheel and put it under load and then attached the slide hammer to the puller A few taps with the slide hammer the key just collapsed and the flywheel came off.I think I also warmed the flywheel up with a gas torch. Hope this helps. Good luck Arthur