Wednesday, May 9, 2012

Refitting the swinging arm, rear shock and centre stand

The swingarm had suffered from scuffing towards the left-hand end. It also had pitting from corrosion in areas where water and salt had crept under the chain guard and gator which connects to the rear mudguard. I treated those areas with special metals primer, topped off with silver Smoothrite. When the mudguard and gator are replaced, they'll be hidden anyway - it's good for me to know they'll be protected from similar problems in the future. 
The main  suspension components for the swingarm include hollow spindles for two drop links that connect to the drag link. The spindles have grease nipples in their outer ends - these appear to have been used as intended.  The spindles fit through three short sleeves in the swingarm casting. These had suffered a bit. The drop links have needle roller bearings at each end and are both protected from the elements with decent seal arrangements.  The top bearings benefit from large steel and rubber seals, the lower bearings are looked after  by pressed-in rubber seals. All were in good condition. 
Drop links - Meriden-style
logo on these early castings

Needle roller bearing was in
great condition, visible here after
cleaning out the old grease with parafin

 I reassembled the drop links with new sleeves and a combination of Castrol LM for the needle rollers and Rock Oil rubber grease for the seals. Torquing up the spindles is a bit tricky - the trick is to use a socket for a 12mm spark plug because these are 18mm across the flats.

The chain has to be looped over the left-hand leg of the swinging arm first. The swingarm slides in between the frame outriggers and steel castings. The castings should be left loose at this stage - a bit of movement is helpful to get the swingarm positioned properly. The swingarm spindle is inserted from the left because it makes it easier for dealing with the chain. Stop when the spindle gets to the first steel casting. An alloy spacer must then be inserted between the steel castings. 


Alloy spacer in place between the two steel
castings. The return springs for the centre
stand are visible, hooked on to small
protrusions on the castings. 
 The rear shock is best mounted after the alloy spacer - there is very little room for manoeuvre when the shock is in place. I supported the rear of the swingarm with bungees looped over the frame. This helped maximised the room I had for wiggling the shock into position, and then to line up the shock's lower eye with the bottoms of the drop links for inserting the drag link spindle.   I put lots of grease on the edges of the drag link that would but up against the drop links and shock. There was a fair amount of corrosion on the drag link there, especially to the left of the shock mounting point. I'd seen this on all three of the drag links I'd looked at previously so it's well worth the trouble of slapping on the LM at this stage.

Inserting the drag link spindle from the right-hand side
through the right-hand drop link, shock lower eye
and then manoeuvring the left-hand drop link into place.

The large hex bolt with grease nipple about
to be wound in to the left-hand end of the drag link spindle. 
I decided to polish up the eccentric adjusters for the rear wheel. They were scarred by heavy-handed attempts to refit the rear wheel in the past. I got most of them out with wet and dry abrasive paper on thick pane of glass. Then I polished them with drill and mops. 


 The centre stand fits to the lowest holes in the steel castings. I found it easiest to attach the return springs by looping a 12mm ring spanner over the lower ends - it meant I could get a good grip to pull them over the prongs on the stand.

All sorted, ready for the rear wheel.




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