Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing king pin bushes

The first bush is the hard one. The second one drifts out easily with the tool which is heavy duty and also perfect. I did consider drifting one bush down until it contacts the second and then drifting both out, but the prospect of both being stuck put me off.

The sad thing is that new bushes fit perfectly over a new kingpin. The stub axle tube is misaligned when the fittings are welded on. I also considerd having the stub axles line bored, but obviously then you have the issue of securing the bushes so they don't move in the stub. A skilled engineer could line bore, secure the bushes, and the kingpin would just slide in without reaming. I've never heard of that being done, which suggests it's not worth the time and effort!

I tried the socket idea last night, but I couldn't get the bushing to move. I'm not going to reinstall and ream them anyway, so I'll let the shop that will do the work get them out. They have the technique.

Absolutely nothing to do with the tubes being misaligned during the welding process. I've retubed several stub axles and I've clocked them up in the lathe afterwards which has shown nil distortion post welding.

Issue with line boring is that it is practically impossible to maintain any meaningful accuracy over the distance of a stub axle tube in a lathe You would probably need a boring bar overhang of at least 10.5" inches, the flex from this, coupled with an unbalanced work piece such as a stub axle would cause chatter in the machined surface!

Arwyn

So what causes the bushes to nip up when installed? Is it because the tube is just off round?

Physics and metallurgy......

Quite simply, you are forcing a soft hollow round piece of metal into a harder round piece of metal as you don't want the smaller piece of metal to fall out.

The smaller piece of metal being ever so slightly larger than the hole in which it has to fit.

Which causes the sidewalls of the bush to distort and the kingpin not to fit the bushes, hence the need to ream them so the distortion is removed and the king pin fits the bushes once again.....

Arwyn

Dave

Am I correct in thinking that you have a pattern for rebound spring gaiters? mohair and velcro??

Yes Gary, I'll send a PM tomorrow.

Mike Duncan made a tool for drifting out bushes. Basically a stepped drift with three "segments" that slid in and then were held by the centre of the drift. Worked well.

Dragging the bushes out might be another possibility. My contraption uses a little elliptical plate that passes through the bush bore and then flips over in the tube before attaching to a puller bolt. It hasn't been used in anger yet. I traded the car that I was planning to use it on for my current one so still waiting for some slack in the pins. No idea if it will work or not

I just set them up in my 30 ton press with a modified press block and a mandrel and use the bottom bush to push the top bush out after removing the grease nipples

Times money ....

Arwyn