Date: Fri, 21 Aug 1998 11:07:20 +0100 (BST)
From: Peter Aslan.
On Thu, 20 Aug 1998, evanspa wrote:
>I am about to try to cure handling woes by replacing worn swingarm
bushes on
>a 74 850 but I am having problems getting the swingarm bush cover
off. Is
>there a secret to getting the thing off. Manual says that after removing
the
>cover screw the cover should just come away. Before I prise it of
off and
>damage it I just thought I'll check first on my new source of information.
>thanks Phill Evans.
There are at least two different types of Swingingarm Bush Covers. The one's originally fitted to my 1974 Commando were of the Core Plug Type. These are domed metal plates, which are, interference fitted to the swinging arm. Inside the swinging arm is fitted with felt wicks which are supposed to hold the oil for the bushes. With this style of cover, there is no way to put any lubrication into the bushes.
The second type, and the one you see more often in the manuals, is the flat metal disk, held in place by a long 4ba bolt between the plates which pulls them together. This type is usually fitted with a grease nipple to allow Oil, SAE 140 to be added to lubricate the bushes.
The first type, core plug, usually gets destroyed being removed, which is a Good Thing (tm), in my opinion as they were rubbish. They can be replaced with the other type, although this will require some machining, as the OD of the Plates is to big for the swinging arm with the short bushes, (oh did I mention that there were two different types of bushes ?)
I did the modification noted above to fit the non core plug type plates with an electric drill and a file, although I suppose you could do it with a lathe :)
When I fitted the new bushes, I used a length of studding and a couple of Nuts to pull the new bushes into the swinging arm, and I did not find it necessary to ream or machine the bushes, the old spindle worked fine.
The hardest problem is usually in removing the spindle in the first place, make sure you have good purchase on the thing through the treaded hole before you start pulling.
Regards,
Peter Aslan (aka Captain Norton). Louden Quill Award.
37.2 Improvements in Swinging Arm attachment.
Date: Sun, 23 Aug 1998 15:09:32 -0600
From: John Schmidt
Chris, best perhaps to contact Heinz directly, but since my bike was the test bike I can help you, If you can grab the rear wheel while on the centre stand with the left hand and keeping a eye and a finger of the right hand on the right side of the swingarm cradle(where the pin and lube goes in), now attempt to move the rear wheel side to side, if it will move at all that is still no good but assuming your rear iso unit is shimmed at no more than 15 thou play, any other movement is the interior steel pin has worn away at the inside of the cradle it rests and is lubed in. Most people believe the bronze oilight bushing are shot, not true, as the worn part is the interior of the cradle itself. Heinz makes up two(2) split rings that bolt together around the outside of the cradle and then you drill a hole through the cradle from underneath at about the 8 o'clock position looking at it from the right side of the bike, then the rings go on spaced about an inch and a half apart and a bolt goes through each ring and into the hole in the cradle you just drilled, the bolt forces the interior steel pin hard forward against the inside of the cradle, thus eliminating all play there and consequently where you would feel it, in the movement of the rear wheel itself. The bolts are secured by lock nuts and are an easy and cheap fix to this problem. The installation itself takes about a couple of hours given much time to fool around and not really work at it. You do have to take the oil filter off to get the rings around the cradle initially. Heinz's fix is superior to the Norton Tech tip because it is inherently much stronger as the securing bolt is held by the 360 degree rings, and in the tech tip the bolt is held only by the ability of the welded or brazed nut to stay in place in the 8 o clock position. I believe Heinz is selling them with complete installation instructions for about $125. He machines them himself. They are his design.
When we are born we cry, that we have come to this stage of fools.
Lear 4.6