Assembly is the Reverse of Disassembly, or Windshield Wipers Part 2

In Physics, the 2nd Law of Thermodynamics might be paraphrased simply to say that things get more disorganized over time.  It also leads to the conclusion that some processes in nature are irreversible.  This reveals the folly of a constant refrain of the MGA workshop manual, the deceptively simple sentence "assembly is the reverse of disassembly". As in many things in life, tearing things apart is much easier (and to twisted minds more fun) than putting things together. These were the thoughts that kept me company during the next several days of reassembly of the wiper system. 

Rust and old paint sanded off (mostly).

There is a flexible rubber sealing fume excluder and a frame that cover the tops of the pedals - the rubber was partly disintegrated so I ordered a new one of those.  The metal frame that holds the bottom of the rubber to the heater shelf was rusty with some old paint.  I decided to sand off the rust and old paint and re-paint with black Rustoleum. I couldn't quite get into some of the rust pits, but decided this was an inexpensive and non-structural part and I could take the risk of the rust continuing to grow under the paint.  For future projects like this I put a rust dissolving chemical called EvapoRust on my Christmas list (a sign of how twisted my thinking has become).


I'd decided to rehabilitate not only the motor unit, but the little gear boxes that directly attach to the wiper blades under the skin of the car and transmit power from the motor, which moves a slotted cable back and forth through a bent system of tubing in contact with these gears. I cleaned out old dried grease, re-lubricated, and started putting things back together. The gear boxes can be reached by lying on your back with your head in the foot well, part of your back in the foot well, another part of your back on the seat (it helps if your spine can flex into a "Z" - mine can't), and your feet up on the back of the car. You then reach your hands up zig-zagging through wires and other obstacles to assemble the little piping sections into the gear box while tightening a tiny screw at each end. This screw is more affected by gravity than most things, so it likes to fall on your face and roll to spots in the foot well that do not exist until you de-contort out of your position. Unfortunately, all of the pipes that will carry the reassembled cable grew by a quarter inch while I was not paying attention and refused to fit back together, at least all at once.  


Somehow I managed to get things together despite not really fitting properly.  The next step was to feed the flexible cable attached to the wiper motor in through the tubes and wiper spindles. This is a little like pushing a rope up hill through an obstacle course. I spent at least an hour of trying to force this arrangement to work while levitating myself over the engine bay and twisting the wiper spindle by hand. Finally it dawned on me to double check that the spindles were in the right way around. Sure enough they were rotated 180 degrees.  I'd carefully thought this through, but somehow lying on my back I swapped things around in my head. 


Uninstall everything and back to the beginning. This time things fit right and went back together a lot faster than the first time.  I got back to the task of pushing the wiper cable in and it was also much easier.  I used a pair of pliers on the wiper spindle to help move things along and got it installed all the way in. Now just to connect the flange nut securing the start of the piping to the wiper motor housing.


Now, if you have read patiently through this whole thing this is where you get the pay off.  It was at this point, as I slid the flange nut up to the wiper motor housing that I made a horrifying discovery. The nut was the wrong way around.  How could that be since both ends of the tube are flared and the nut doesn't come off the piping?  I'd flipped the pipe wrong way around when putting it back in.


Uninstall (almost) everything and back to the beginning (again). Now that I was an old pro at the procedure, things went back together with relative ease. No mistakes this time - everything went back together. With an hour or two at a time to work on the project, the reassembly had taken a few days. I got the wires hooked back up and anxiously gave the wipers a try. They moved half-heartedly part way through the arc but definitely were not quite right. At some point in the future I'll be ready to dig back in to figure out what is wrong (probably the commutator was not clean enough or the spring holding the brushes tight against it is too weak), but I just didn't have it in me at the time. I put the pedals back in and got the car back on the road.