Swing arm play

My newly bought 72 Commando weaves over the road at any speed.
It has been totally rebuilt - by previous owner - but the swing arm can be swung sideways by about 2 -3 mm.
There is no axial movement. I took it all apart and found the bushes and shaft are fine, no slop.
The problem is in the tube welded to the cradle, and the cradle plates. The shaft has about 15 thou radial clearance in the cradle/tube.
Although there is a small bolt holding the shaft from rotating it can't stop it pivoting.
I have read a lot in this forum about clamps etc to hold the shaft in position, and about ovalality of the tube.
I don't see how the tube/cradle can wear as the shaft is not rotating.
I intend to fix the problem by putting a small blob of weld on the front and bottom on the tube entrance and then filing the blob away until the shaft can be pushed in with medium force. Unfortunately the engine will have to come out to do it - unless I weld the RH side only - should still cure the problem.
Comments anyone?

No problems........

Have a read though this

heinz-kegler-clamps-t18463.html?hilit=cradle%20mod

Its to you what way you want to eliminate the slop in the tube , but a few "blobs" of weld here n there :roll: :roll: :roll: :roll: .. If you can weld and can source a few nuts (can do better than nuts, turn something up) and grub screws is inexpensive or the clamps are a common resolution...

Definitely try the collars and let us know your sense of it but may have to renew rear tire to know for sure. I have found drive chain flap can tug enough on loose spindle to make it randomly drift either side inbetween intervals of just fine. I have Hienz collars that were gun blued to 'protect' but wet grit can seriously rust em so provide protection if not arriving that way. Its the fasterner and trap bolt threads at most risk to become unremovable.

There is an oversize pin available (+ 0.005" I think), but it sounds like you are beyond that and reaming is needed of course. Best bet for you seems to be the collar and clamp method. If you just build up one end with weld the pin will be cocked in the bore and alignment will be out but that appears the least of yr problems. Here's mine with bolts using a new pin with flats (for mk3 cotter pins). Mine is tight and this was the PO effort to improve things....

Thank you all for your help/advice. Maybe I'll do it properly with two threaded stubs welded on - it will have to come out anyway.

Mine was not as bad as yours, but just the clamps seemed to do the trick for me. Before the clamps, I found a cradle on Ebay for about $10 and postage. It was in about the same condition as mine. I thought I would get it modified and reinforced, and then just swap them out. But, before that I got lazy and just did the clamps since the concensus seemed to be that they are pretty good. The original tube that the center bolt is mounted too is way too thin, and that is probably why the clamps work pretty well (crush it to shape and/or provide more rigidity for the new set screws). You might want to get a spare and experiment.

RichardNS said:

My newly bought 72 Commando weaves over the road at any speed.
It has been totally rebuilt - by previous owner - but the swing arm can be swung sideways by about 2 -3 mm.
Comments anyone?

Click to expand...

After replacing iso bushings with the MkIII adjustables and adding clamps to the swing arm pivot, it turns out that the biggest culprit to my over-65mph weave was caused by an old, square-edged, out-of-balance rear tire.

Nathan