Apr 242012

As with all the other electrical units, the alloy parts were was ultrasonically cleaned and then sprayed with Gtechniq S1 SmartMetal while the other steel parts were zinc-nickel plated. The next two tasks were to sort out the gearbox lid which had been distorted and also to strip and paint the yoke.

The offending motor gearbox lid after several attempts at heat shrinkingThe centre area of the gearbox lid has been stretched at some point. Therefore its outer perimeter no longer made a continuous seal and so would allow water into the gearbox housing.

The suggested solution was to heat shrink the centre section of the lid to reverse the deformation – heating the centre of the lid to near red heat and then rapidly cooling. After several attempts of heating the lid with a gas blow torch and cooling using a can of compressed CO2, all I succeeded in doing was to work harden it in exactly the same shape as before. Aaaaaaargh!

It probably needs to be heated to a much higher temperature using oxy acetylene. In the end I cheated to avoid holding up the rebuild and obtained a replacement lid. When I get time I’ll give it a proper go at flattening the lid, as I would like to keep the original with the correct stampings.

The wiper motor yoke painted in silver hammerite .... at some point I'll repaint in the correct colourNext up was the yoke which contains the two permanent magnets. The magnets can be removed by lifting the retaining clips so the yoke could then be shot blasted before being painted in silver hammerite. I was quite pleased with the finished article even though the silver hammerite was not quite the correct colour.

During the refurbishing of the cooling fan motors I had found a dark silver hammered paint from Rust-oleum, which is very similar to the orginal colour. At some stage I will re-paint the round bodied yoke but decided to put it off for now. Mainly because of the difficulty I’d had getting a good finish with the Rust-oleum product.

Fortunately the armature wasn’t in such a bad state as those in the cooling fan motors and so all that was required was some light wire brushing and polishing before the S1 SmartMetal coating. I had investigated the availability of new brushes and parking switch units but these seemed to be rather difficult to get hold of. Therefore when I spotted a ‘new, old stock’ brush unit for sale I thought I’d get it as a spare for the future. However I’ve not yet found anyone who can supply the parking switch units.

Cleaned armature Triple Brushes Wiper Motor Parts

The armature was wired brushed to remove the worse of the rust. It was then polished and finally sprayed with Gtechniq S1

The armature brushes and parking switch unit

The wiper motor compentent ready for the rebuild, including the spare armature brushes unit

The rebuild starts with installing the armature brushes and parking switch unit, as these are wired together. The brushes are secured by three small setscrews and the connecting wiring passes through a notch in the motor gearbox housing.

The parking switch is secured by two setscrews from the inside of the gearbox compartment, as shown in the middle photo below. This also shows the protruding parking switch plunger which is activated by a cam on the underside of the gear wheel. The cam positioning is such that it operates the switch when the wiper blades return to their normal rest position.

First fit the brushes Parking switch attachment ACF50 applied to Yoke

The brushes and the parking switch unit are the first to be fitted

The parking switch is attached by two setscrews from inside the gearbox housing. Note the switch plunge which operates when the wipers return to their normal rest position

The interior of the yoke was sprayed with ACF50 which provides a good protection from moisture

After several attempts at fitting the armature and yoke, I found it easier to first fit the armature into the brushes and motor gearbox and then fit the yoke. With this approach its was necessary to hold the armature’s worm drive from within the gearbox so that, when fitting the yoke, the yoke’s magnets didn’t pull the armature out of the brushes. Also don’t do what I did and forget to fit the plain washer between the armature and motor gearbox housing!

Care was also needed in making sure that the thrust and fibre washers were correctly seated in the yoke bearing housing. The easiest way to do this was to join the two with yoke positioned so the ‘bearing’ housing was facing downwards.

Initially I tried to put the armature into the yoke and then attach them both to the motor gearbox. However the problem was it was then difficult to withdraw the three sprung brushes at the same time as inserting the armature, because the yoke restricted access to the brushes.

The middle photo below shows the arrow head marking on the motor gearbox and a corresponding line on the yoke. These need to be aligned when refitting. Also shown is the threaded armature stop. This was then screwed into the gearbox housing until it touched the nylon cap on the armature shaft, before being backed off a 1/4 of a turn.

Next fit the armature Alignment markings Belleville washer goes here

The brushes were then withdrawn to allow the armature to be inserted

The markings on the motor gearbox housing and the yoke must be aligned when re-fitting

The Belleville washer provides pre-load for the armature shaft

The Belleville washers is then positioned within the gearbox before inserting the geared output shaft. The rest of the gearbox was then filled with grease before the output rotatry link and gearbox lid were refitted. The rubber moulding sealing the output shaft area had hardened and split.

At the time I dismantled the motor, it was one of the few parts that wasn’t being remanufactured. Probably because it was only used on the Series 2. However by the time I has started the rebuild, one of the suppliers had made a small batch so I decided to grab one while still available.

Re-packed with grease Output rotary link Motor rebuild completed!

The geared output shaft (just about visible) was inserted and then the remaining space packed with grease

The output rotry link was refitted which also secures the geared output shaft. Although I'd forgotten to insert the rubber seal first .... so I'll have to refit it

The completed wiper motor

The only thing that remains is to adjust the various wiper motor & rack linkages which can only be done once they’re installed in the car. People usually leave the installation of the windscreen until the latter stages of a rebuild. I guess this is because it would restrict access to dash area. However I’m tempted to install the windscreen as soon as the dash wiring looms and dash panels are in place. Therefore I’ll be able to adjust the linkages before the bulkhead access become restricted.

Apr 242012

I was surprised how rusty the clutch pedal and pedal springs were seeing it’s inside the car and underneath the aluminium pedalbox housing. I’m assuming this must have been as a result of condensation. Once it’s complete I’ll give the inside a covering of ACF50 to give it some protection. There’s nothing worth noting on the dismantling as the pedals simply rotate on a shaft through the pedalbox.

The pedalbox was renovated before I’d come across the company that ultrasonically cleans alloy components, so it was shotblasted and then coated with a lacquer product sold by Eastwood to stop surface oxidisation. The pedal arm, foot pads and springs were also shot blasted and then powder coated.

The rebuild was fiddly mainly because the pedal springs are quite strong so it’s difficult to align everything while pushing the shaft into position. The final washer had a tendency to drop out at the final moment! It made sense to cover the shaft and mating surfaces in plenty of grease.

I was surprised that the brake light switch is actually part of the hydraulic system, actuated by hydraulic pressure when the brake pedal is pressed. Some have reported problems with the response of this switch and have therefore either replaced it or supplemented it with a mechanical microswitch operated by the brake pedal.

While the car is apart and the looms are being put in place, it makes sense to install both a hydraulic switch and a microswitch in parallel, to build in redundancy. All it would require would be to fabricate a bracket to hold a microswitch in the pedalbox housing. I’ll do this as part of the final electric fitting when the lights are installed.

Apr 152012

Hutsons have fabricated wheeled trolleys so bodyshells can be easily moved between the body repair, paint preparation and spray booth areas. They’re designed so the shell is at a reasonable height to work on without the need to stoop.

Once completed, the bodyshells are then delivered bolted to the trolley which posed the first problem for the rebuild. How to get the painted shell off the Hutson’s trolley and onto my waiting axle trolleys.

I had initially planned to do the body work myself and had started to make a rotisserie during the dismantling stage. Its base was a rather substantial affair, built out of lengths of 150mm mild steel channel. The car was delivered to Hutsons on the frame, but as I wouldn’t have further use for it, I left it with Hutsons to dispose of or use as they wished.

They’d put it to good use. When the bodyshell was delivered, they had modified their lorry’s tailgate so the long lengths could be bolted on to act as ramps. Their trolley could then be rolled down the ramps in the channels to safely deliver completed shells.

Unfortunately there wasn’t enough manpower around when the car was delivered to lift the bodyshell onto the axle trolleys. It had to remain on the Hutson trolley while I pondered what to do.

Even with the axle trolleys at their full extension, the bodyshell still needed to be lowered by approx. 40cm. None of the local hire shops had anything suitable to raise and support both ends to allow the trolley to be removed and then lower the bodyshell.

I then looked at erecting four columns of building blocks to support timber cross beams. This would also need two other columns to provide a raised base for the trolley jacks. The number of building blocks needed was mounting rapidly, making it a rather expensive solution for a one off job. I was stumped.

The timely delivery of some timber for a workshop provided just enough wood that could be temporarily half-inched to make supporting platforms either side of the car. Also I wasn’t comfortable attempting to lower the bodyshell on my own and drafted in some much needed help.

An initial recce was duly arranged to plan the lowering however it was soon decided to go for it and the oversized Jenga operation began. The bodyshell had to be raised and lowered a number of times – raise, roll the trolley forward until it hit the platform supporting the jack, lower, reposition the jacking platform. Finally the trolley’s exit route was clear and it could be pulled free.

It this point the bodyshell was in its most precarious position, supported only by three jacks. Not good for the nerves!! The final lowering was relatively simple. The front and rear ends were raised and lowered in turn with a layer of timber removed each time.

With the sun low on the horizon, the bodyshell was at last resting on the axle trolleys. Phew!

 Posted by at 10:04 pm