The spindle of my MK 2 850 US spec commando has seized badly into the gearbox cradle. short of large drift and mate with 7lb sledge hammer I am struggling to get it out. Any tips/ideas welcome. I have soaked it in plus gas and tried drifting it out from both sides (primary drive stripped off) but to no avail. I have ordered some 1/2 uni bolts and nuts and will try to get it to turn with 3/4 drive socket set Tommy bar (about 18 inch long) if that does not work some heat and drifting shall be tried. Fit in cradle may be gone now due to rust.
Any suggestions welcome.
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.
Thanks a lot I was using the front isoelastic bolt and did not want to trash it when the new unf bolts arrive I will get the blow lamp out and I have a 5 foot thick walled tube that will fit over the breaker bar.
many thanks Bill Downie
PS owned bike since new so only self to blame. Any suggestions for better lubrication ?
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)
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.
You are probably correct but mine has the 1/4 inch set screw in it which is removed quite easily I have to say so nout but rust holding it in now. Oil tank out for refurb and rear mudguard and horn removed for access so I am hopeful about the heat and turning to initially free it. Thanks for the info though
Tried your suggestion and sheared off the head of one of the short bolts I used in the spindle. I now intend to remove the oil filter and associated pipes to get better access to heat up gearbox cradle and I shall shorten bolt on primary drive side until the head bottoms out on the spindle thread. I will try to get it to turn but it is well stuck in, 18 inch breaker bar plus 2 foot extension tube and no tuning movement yet. If this does not work I shall try a bigger drift and the 7 lb sledge. After that remove gearbox and then cradle/swing arm unit and get someone with a very large press to try and push it out. Last resort get new cradle and swing arm (£££££ ouch !!!)
Bill D any other suggestion welcome ???
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...
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.
Gearbox cradle with swing arm attached with seized spindle removed from frame now. I am Taking it to my engineering local company to see if they can press it out. Otherwise machine out ends of spindle and get new gearbox cradle and bushes etc etc . May convert to cotter type but last problem is any play between cradle and spindle it is seized solid. If I ever get it sorted it is getting removed and oiled annually from now on. Worst bit of design I have ever seen???
A Geordie, you are?
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.