Rear mudguard, expansion tank and chain guard

 Unsurprisingly, there was a lot of corrosion on the rear mudguard fixings and brackets.

Drilling out remains of ally rivets that
hold a rubber gator to the mudguard

Coolant expansion tank with failed
rivets on a metal bracket that holds it to
the rear mudguard. Outer holes have captive nuts
for expansion tank bolts. 

The coolant expansion tank is bolted to a steel bracket, which is in turn riveted to the mudguard. The rivets had failed and the plate heavily rusted. The expansion tank bolts run through brass sleeves - they were corroded too and needed soaking in WD40 for weeks to release. Heat wasn't an option with a plastic tank. Got there in the end though.

A rubber gator bridges between the forward edge of the mudguard and swinging arm. It is riveted to the mudguard through a metal plate, and to the swingarm via another metal plate. All the rivets were heavily corroded, their aluminium heads basically dissolved.

Grommets and rusty spacers

Repainted spacers

 The mudguard is bolted to the frame via rubber grommets and mushroom shaped steel spacers.
 I gave everything a good scrub up and derusted the spacers prior to repainting. The metal brackets were not worth saving. I made up replacements from 3mm aluminium plate.

The bracket for the expansion tank was very simple - just a strip with four holes in it. I decided to cut M6 threads in the outer two to accept the bolts for the expansion tank and to use lock nuts for strength.

The lower bracket for the gator was a bit more involved. It has an S shape profile, with three 5mm holes for rivets uppermost and two 8mm in protruding lugs on its lower edge for bolting to the swing arm.

Two aluminium plates to replace failed steel items - top
bracket in picture is for expansion tank, bottom for lower
edge of rubber gator.

I made up an additional gator (or mud flap) to fit beneath the standard gator, to give the shock absorber and its linkages a bit of protection from the elements. I shared the M8 bolt holes in the swing arm  for the standard gator's lower bracket and my additional gator. Rubber isn't very strong so I made up an extra aluminium strip to spread the load from the bolts across the width of the extra gator. The gator was made from a cheap car mat.

I painted the ally with special metals primer and Smoothrite black, and used some A2 bolts, washers and domed nuts to hold it all together.

Lower bracket for standard gator plus additional gator
in place on swing arm, VA2 dome nuts gleaming away.

Re-riveting the lower edge of the standard gator
to the replacement aluminium lower bracket,
and preparing to do the same to its upper bracket

 When the standard gator was riveted to its new ally brackets (painted black) and the coolant tank bolted up again, it was a bit of a job to fix it to the rear frame rails. The plastic is very robust but very flexible at the same time so it needed a fair bit of jiggling to get the bolt holes lined up.

Expansion tank refixed to the mudguard, gator riveted on ...

... wiggled into place beneath rear frame rails for bolting up. 

 I used a couple of elastic cords (bungees) to hold it up temporarily whilst I fitted the bolts. It worked fine. However, after I'd finished the job, I tried to fit the wiring loom and discovered that I couldn't get the block connectors through the spaces between the frame rails and the mudguard. Consequently, I had to drop the mudguard back down again temporarily to squeeze them through. So the bungees had a second useful outing for me.

Bungees helped hold up the mudguard whilst I located the
M6 bolts and mushroom spacers.

There was one other riveted bracket on the rear mudguard - a little plate for the flasher relay. I fitted that after the mudguard was bolted up. I used copper grease on all the pop rivets to try to prevent or retard the differential metals corrosion that had caused them to fail first time around.

The chain guard is held on by three mushroom-headed bolts. I decided to replace these with stainless steel button head machine screws with oversize washers.