Swing arm spindle seized in gearbox cradle

Heat the cradle tube the spindle is rusted in, then as it cools run the 1/2" UNF bolt into the spindle and use the breaker bar on the bolt head when it reaches the bottom of the threads to try and get the spindle to turn inside the cradle tube. Once it turns then it should be easier to drive out. Have a long scaffold tube that fits over the breaker bar in reserve to increase the leverage.

Pretty sure I read on access Norton site,  that  some of the late 850 Mk2s  were built with the MK3 style spindle retained by 2 cotter pins at the back of the cradle.  Maybe worth checking before the social niceties go out of the window and the old preswader comes in to play ;0)  

Best regards 

Katherine Scott

It should only need oiling once a year to keep the oilite bushes topped up but the spindle can get dry. If you take an Allen bolt 1/4" UNF 1 /2" long and drill a 3 mm hole you use it to replace the spindle locating bolt. You can put a pipe on the Allen head and run it to a small oil reserve. 

Did mine a year ago, took all the covers off and bolt out of the centre.  It was totally seized and a heavy hammer sorted it. 

Once out it was obvious that the spindle had badly corroded and locked in the bushes. I was advised that the bushes are very hard wearing and to try the new spindle in the old bushes. Having cleaned them up the new spindle was a perfect sliding fit with no play.

Soak in phosphoric acid?.

Depending on the depth of corrosion. I note you mentioned Plus Gas which in my experience has been effective in the past. So I guess it’s well stuck. Go in stages in both directions until you get movement. Keep washing it in what ever release agent you have.  Slide hammer preferred to sledge.  You could also use plumber’s pipe freeze spray internally to shrink it away from the bind.  Slowly but deliberately with the frame well secured  so all the effort goes into the “joint” ...

Get a mate round to work on it methodically...

Good luck

Jon

That firmly, then the best action is to go directly for the press out route as you suggest as 'last resort'.  Less likely to damage or distort something else than whacking with large hammers could do.

What I have done in the past is use some big washers or spacers, that clear the spindle, on the end of the swinging arm & then smaller washers on the end so that a 1/2" UNF can be screwed into the spindle & pull the spindle. A bit at a time, then add more spacers. Depends on what you can find in your garage. Could hit t'other end when in tension.

My mod for oiling the swingarm, was to replace the locating screw with a stainless steel one tad tougher and drill a small hole part way up and another at 90° to it you only have to take it part way out when you pump the oil in. If you don't when you pump the oil in you're in danger of snapping the piddly 5 ba screw.