I wouldn't go that far

You need to do two runs, both very hot, about 1/3 of the way down and 1/3 of the way up the end of the arm. We did this on the Spa racer last year, it worked very well indeed.

I shall try it some time. Gas or Elec. I'm an oxy accet man myself

P

Mig worked for me, Arc would be better I think. You can probably heat the arm with an oxy torch and it'll shrink enough.

I have an arc welder as well. I'll give it a go.

Mind you, I don't have any bad king pins at the moment

P

Russell,
I doubt that just heating the arm will do the job, since it's shrinkage of the weld bead which pulls the bore inwards.
I'll bet you've noticed how a heavy fillet weld will pull a joint out of square as it cools...

I've done 'more than a few' of these and I reckon that they're usually required because 'someone' has used the wrong type of drift when removing a kingpin.
Too hard and it 'mushrooms' the top of the pin, gouging material out of the bore as it's driven out.

ken

King pins are inferior fit to ensure a correct bite preventing the pin to move upwards.
When stuck applying heat to the arm springs to mind and yes the arm will expand but after pushing the pin out, the hole do not shrink back to same diameter.
Pushing in the new king pin will remove some metal. Do this a few times and the hole becomes too big and you have a loose king pin problem. I’ve done many pins and never use heat. Good old fashion shock technique is the ‘’right’’ way to remove the pins. Loose pins will move upwards and knock the grease cap off and touch the drive shaft. Some ‘’mechanics’’ just give the cap a welding spot to keep the pin from moving. Loose pins will result in various steering and handling problems.
I simply fit an oversized pin 17,1 or 17,2 and the problem is solved.

http://www.aussiefrogs.com/forum/showpo ... tcount=108

I've got a press to remove king pins that my dad made many years ago when rebuilding a Dyane for my 18th Birthday (41 now!). It's essentially the same as that shown in the Haynes manual. Is this no better or worse than the shock technique? I'd always assumed constant pressure was potentially less damaging than the judicious application of a large hammer & drift.

Said press is available for loan should anyone wish to use it btw. Postage to Oz probably exorbitant!

Viking,
slight misunderstanding there, as nobody has mentioned using heat to help remove a kingpin.
What was actually being discussed was using a run of weld on the outside of the boss to shrink the bore and so restore the original interference fit of a pin in the arm.

ken
( Btw, when fitting a top bush, I don't understand why you advise against using drift No 6 as once that's engaged in the lower bush, there's no way that the top bush can tilt.)

No worries for using a press if the pin is moving and not stuck. However if the press can't push the pin out as mentioned in the job from Oz, the shock technique is the only way to go. Done properly, no harm at all. Too much heat can be a problem making the hole too big

Thanks for the disscussion.

I`ve used a similar technique on steering head bearings on motorbikes when a bead of weld shrinks the race and allows it to be removed easier.

I think i will put it all back together with the new kingpin and bushes greased up and see how it is.

Medium term ilike the sound of the oversize king pins and bushes,so i will measure the internal diameter of the arm hole before put it back together.

Welding could be an option but i will have to take the car into work as there is a better welder there!

Thanks again for everyones help. Andy