Wiper Problem (possibly fixed)

[svenedin]

I was out today in bad weather with the wipers on. After driving for about 15 minutes the wipers started going slower and slower and came to a complete halt. This was doubly inconvenient as it was raining hard and the wipers stopped in the fully up position.

We pulled over and I checked under the bonnet. No obvious loose connection but the wiper motor was noticeably hot. We went for a walk as the dog was in the car and that was the intention of the journey anyway. On return to the car 30 minutes later I removed the Lucar connections from the motor and replaced them and unscrewed the earth connection (ring terminal), replaced and tightened back up. The wipers then worked fine and on return home I checked and the motor was only just warm.

My question is, was it just a bad earth connection? It seems so. Of the 3 connections to the motor only the earth ring terminal looked corroded. Should I be investigating further? I would rather not have this happen again. It is quite dangerous to drive with no wipers in the rain!

[mogbob]

Stephen
I think you've nipped the problem in the bud. When you have a moment , I'd' clean up the corroded Earth ring back to clean metal. Emery paper or a small brass brush. Ditto the fixing point / stud .Re- fit firmly and cover with Copa ease or a dab of vaseline to protect it for the future.

The Lucas DR3A wiper motor is quite robust. With advancing years and thousands of miles they might need new carbon brushes ( if old brushes are down to 1/8" left ) and a quick clean up of the commutator whilst you have it dismantled on the bench. Don't dismantle without prior knowledge or
a good appropriate Manual.
The work requires " a gentle touch " as the insulation separator is easily broken and the tiny springs are delicate. Ham fisted mechanics beware.
At the same time , if you thought it advisable , you could remove the main cable that goes through the Bundy tubes. Either a degrease / clean of the cable ... a messy job a bit like wrestling an Octopus ... re-grease with fresh grease and re insert. If badly worn reset 180 degrees from original position, thereby using the unworn side of the cable. Old dead grease slows up the back and forth motion and can eventually bring it to a complete halt.
Resistance to movement will induce strain on the motor , leading to heat generation.


Enough of the scary stuff. Just keep an eye on it for the moment. A "duff "earth was the most likely cause of your overheated wiper problem.
Bob

[svenedin]

Thank you Bob! I will certainly clean up the earth connections. I am not ham fisted, one of my other hobbies being watchmaking, but I do not have a manual or any prior knowledge of the insides of the motor. In the 34 years I have owned the car I confess that the motor and cable have never had any maintenance whatsoever. A reconditioned motor is quite expensive and I would far rather keep the original working than do an exchange. I did wonder whether old grease/lack of grease was causing the motor to work too hard and overheat but after re-making the earth connection the motor was not hot after 20 minutes of using the wipers so I am hoping it was heat generated from the high resistance of a bad electrical connection. I did have a quick search online and new brushes are available.

Stephen

[mogbob]

Stephen If you have Watchmaking skills , then I'm preaching to the converted !
I have two pals that I've helped with Classic car restoration. Both have a tremendous , enthusiastic approach to dismantling car parts in the shortest possible timescale. Unfortunately an element of finesse in their approach is missing , a lot of the time. I have received numerous phone calls over the years , along the lines of " I've sheared the bolt , bent the shaft , destroyed the fixing... what do I do now Bob ? I've almost completed their re-training
but there is still the occasional lapse ! Both good mates.
Bob

[svenedin]

I looked into refurbishing the motor assembly. I have decided to send off my unit to a specialist in wiper motors for refurbishment (Smallman Hall Classic Cars). This is considerably cheaper (£150) than an exchange and keeps my car original. It is working but way overdue some maintenance and this is safety critical equipment. The reason for not having a go myself is that if I find worn parts they are difficult to find and expensive if they can be found at all. Whilst the motor is away I will replace the rubber mounts, remove, turn 180 degrees and grease the rack, rotate the wheels 180 degrees and replace the wheel box bezel seals. I confess to being reluctant to do this job because I really don't like any job that involves taking out the gloveboxes!

[svenedin]

I have the wipers off now. The splines on the wheel boxes look absolutely fine. I have given the chrome nut a good drench in PlusGas and will leave it for a few days before attempting to get the bezel off to replace the seal washer (I can already see a black mess which is presumably the remains of the washer/gasket). Wiper arms look fine with minimal corrosion of the spring. Despite that they've had a clean up and some protective grease sprayed on the springs. The arms are the stainless steel type and have lasted over 30 years.

[mogbob]

A link to Moss with a diagram of the parts you might need for the refurbishment , other suppliers available of course.
https://www.moss-europe.co.uk/windscree ... 51-71.html
Bob

[svenedin]

A link to Moss with a diagram of the parts you might need for the refurbishment , other suppliers available of course.
https://www.moss-europe.co.uk/windscree ... 51-71.html
Bob

Thank you. That's an excellent diagram. I will try to reuse as much as possible unless worn out. So far I have only ordered the rubber motor mounts and gaskets for under the wheel box bezels. Oh and some glovebox screws and clips. Bound to lose those. I am hoping that by turning both the rack and wheels 180 degrees they will be using unworn parts. I will attempt the strip-down on Thursday when I have a day off. I will clean up the wheel boxes thoroughly and re-grease. I am not quite sure how I will clean out the Bundy tube. It will probably be full of nasty old grease in the long section to the motor. With the motor removed I might run some carburettor cleaner down the pipe and use the rack as a pipe cleaner. Carburettor cleaner is really good at removing old grease and as it contains no water it will not cause corrosion. I can catch the muck that comes out of the end of the tube in a plastic tray or something.

[Jim McCrae]

If you can pass a wire through the tube with a piece of rag on the end, you can pull this through and remove all the old grease.

[svenedin]

If you can pass a wire through the tube with a piece of rag on the end, you can pull this through and remove all the old grease.

Good idea! Even better wire with rag on the end soaked in petrol or similar. A giant pipe cleaner. Must be very careful it isn't going to get stuck in the tube though.

[svenedin]

I got the wiper motor out today and it is off in the post for full refurbishment. Tomorrow I will work on cleaning up the wheel boxes, rack and Bundy tubes and also put the new rubber motor mounts in. I have heard that those mounts can be difficult to put in. I wonder whether a bit of red rubber grease on them will aid the process? Maybe warm the rubber up with a hairdryer too.

[svenedin]

I got the rubber motor mounts in but they were difficult. I also put in a new Bundy tube grommet through the bulkhead. The nut on the outside of the wheel boxes came off easily but the bezels/shrouds (under which the seal on the outside goes) seem totally stuck. I've left them drenched in PlusGas and hope there will be success tomorrow. Passenger side glovebox was easy to remove but the driver's side was much more difficult. The surround around the driver's side glovebox really does not want to pass the steering column (in particular the plastic casing around the indicator on the column).

One wheel box is fine, the other seems quite stiff so they may as well both come out for cleaning and greasing.

[svenedin]

Both wheel boxes are out. Both had bezels that refused to come off. In the end, after removing the back covers and Bundy tubes, I had to hold the box inside and bang the end outside with a hammer. The are badly corroded and the seals (which are just a pile of black muck) have obviously been leaking for years. The job is clearly way, way overdue. Both wheel boxes are soaking in paraffin. One might be salvageable, the other feels tight and I think the shaft must be corroded inside. It may be best just to replace both of them........The grease that was used is some horrible black/dark grey stuff. It has hardened and is slow to dissolve in paraffin. Carburettor cleaner doesn't really touch it.

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[svenedin]

Following the tip on this thread, I have cleaned out the Bundy tubes using a small plug of kitchen paper soaked in carburettor cleaner pushed down the tubes with some fairly strong wire. This was repeated with fresh paper plugs until they came out clean. A great deal of horrible black grease in the tubes. One of the wheel boxes is a replacement (decades ago); the wheel boxes have different sized backing nuts. Neither wheel box is serviceable and so I am going to replace them and the rack for that matter. I was surprised that solvents (paraffin and carburettor cleaner) were very ineffective at removing the old grease. I had expected the grease to dissolve rapidly. Physical methods were the only effective way.

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[geoberni]

Grease, particularly older more basic formulated ones from decades ago, can quite literally set like stone and require breaking away.
In the 70s, I spent a while doing refurbishment of aircraft actuators; that's the electrically motorised gearboxes that operate valves or other remotely controlled items, things like fuel or air valves etc.
I'd take apart one that had failed, it's records showed it had been perhaps 10 years since it was made, and the failure was just being gummed up with thick hardening grease.
So when you consider that you're taking apart things that were last greased 50+ years ago.....
I had to change the speedo on my car when I got it, as the Mileometer hadn't moved in the past 4 or 5 years. The little plastic gears that turned the numbers had broken simply because the grease was rock hard, so the plastic teeth snapped off.

[svenedin]

Grease, particularly older more basic formulated ones from decades ago, can quite literally set like stone and require breaking away.
In the 70s, I spent a while doing refurbishment of aircraft actuators; that's the electrically motorised gearboxes that operate valves or other remotely controlled items, things like fuel or air valves etc.
I'd take apart one that had failed, it's records showed it had been perhaps 10 years since it was made, and the failure was just being gummed up with thick hardening grease.
So when you consider that you're taking apart things that were last greased 50+ years ago.....
I had to change the speedo on my car when I got it, as the Mileometer hadn't moved in the past 4 or 5 years. The little plastic gears that turned the numbers had broken simply because the grease was rock hard, so the plastic teeth snapped off.

Yes you are absolutely correct. The grease has turned to a hardened mass everywhere in the wiper system. This is why just having the motor refurbished is not enough. There is absolutely no point putting a refurbished motor back on a system with excessive frictional load. I am so glad I did decide to strip the whole system because the leaks from outside into the area behind the dashboard is awful. My only surprise is that the wipers carried on working for so long!

This is a wet glove box with lots of tide marks from previous wetting

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[svenedin]

New rack and wiper wheel boxes arrived. Just a picture of a wheel box with the back plate off showing the interaction of rack cable and wheel box. I post this because, although it is very simple, I could not find pictures of this so that I understood it before tackling the job. I will also try to get some pictures of the arrangement of the wheel boxes and Bundy tubes behind the gloveboxes.

As is so often the case, the new parts are not exactly the same as the old parts. They are quality made in England parts but the design has changed. The new part has a simple gearwheel but the old one has a more complex gearwheel with the teeth in a channel. I am unsure whether this makes any practical difference in use. New parts came from ESM. The old parts seem of superior and more elegant design and I would have kept them but they are too seized (the spindles are corroded and too stiff).

Looking at the parts side-by-side I cannot see how there is going to be the same wiper travel with the new part. The teeth have to be the same distance apart to match the pitch of the rack but the new gearwheel is bigger so surely for the same linear motion of the rack this will correspond to fewer degrees of rotation of the wipers?

New parts:

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Old part:

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Comparison (old left, new right):

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[Sleeper]

If I was you, I'd give the old one a good soaking in some fluid and then dismantle with some gentle heat and pressure , then a damn good clean-up, lube and re-assemble...

John ;-)

[svenedin]

If I was you, I'd give the old one a good soaking in some fluid and then dismantle with some gentle heat and pressure , then a damn good clean-up, lube and re-assemble...

John ;-)

I am inclined to agree with you. The parts have been soaking in paraffin for a few days and one wheel box at least has freed up. I don't think I know how to disassemble them further without wrecking them completely though. For now I have installed the new parts because I do need a car with windscreen wipers!

A few tips to anybody who is going to do this......

Like any job behind the dashboard, disconnect the battery to avoid the risk of shorting out electrical connections.

This is a rare opportunity to replace the bulkhead grommet that the rack tube goes through.

Remember to put the ferrule onto the wiper rack (and the right way around) BEFORE you install the rack. It cannot be installed from the motor end.

Grease the end of the rack that you are going to feed into the Bundy tube under the bonnet for the first 6" or so and then liberally grease the rack as you are feeding it in. This avoids have the long bendy rack covered in grease and getting mess everywhere and risking getting gritty dirt on the grease. I used a lithium soap based grease worked into the rack thoroughly.

To install the wiper wheel boxes it would be easier with two people but there is a workaround. Open the quarter light and put your arm through it and into the glovebox (which you have removed) hole. You can then hold the wheel box inside the car whilst you put the bezel on and start the nut. Obviously put the gasket on the outside of the car first and some red rubber grease on the gasket might help it last longer. Copper grease on the thread that the chrome coloured nut goes on should aid future release. Don't tighten the chrome nut up fully at this stage.

When installing the Bundy tubes inside the car it helps to have the wheel box back plate on loosely. Don't put the wheel boxes in the car without the back plates on as it is really difficult to secure the nuts (I did this and it was silly). Note that the bridging tube that goes between the two boxes has a curve that matches the curve of the car. Put it the right way round. The ends of the tubes are flared and fit into a slot in the wheel box. Make sure they are correctly seated and hand tighten the backing plate nuts.

As you feed in the rack try to keep the Bundy tube in roughly the position it was in when attached to the motor. If you let it slide forwards it creates excessive resistance. As the rack advances there may be resistance when it starts to mesh with the wheel box gear. Rotating the rack helps it engage but you can also try wiggling the spindle that the wipers attach to. If the rack gets really stuck don't force it. Check inside the gloveboxes that things haven't moved out of alignment.

With the rack fully installed test it by moving the rack back and forth (again with the Bundy tube in the same position it is in when attached to the motor). Then tighten the wheel box back nuts (don't go crazy in case you crush the tube). Test again then tighten the chrome nut securing the bezel outside whilst holding the box inside (using the arm through the quarter light trick). Check the rubber seal is in the right place.

That's it. Put the gloveboxes back. .......


Passenger side inside the car (rack not installed)

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Drivers side inside (rack not installed). End tube is not Bundy but aluminium

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Wipe rack with ferrule (not yet greased)

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[svenedin]

Had some fun this evening with wrinkle painting the wiper motor cover. I have never used wrinkle paint before. I watched a few Youtube videos that recommended using a heat gun to get the paint to wrinkle better (and much faster). Great fun watching the paint wrinkle in front of your eyes. Once the wrinkle paint is cured (48 hours minimum) I will reassemble and give the whole outer casing of the motor/gearbox a coat of clear lacquer. I should really have stuffed the inside of that casing with some newspaper before I started......

My junk bedroom that got partially stripped but not yet redecorated makes a great paint room. It's much too cold to paint in my garage or outside.

Paint looks grey but that's the lighting. It's gloss black actually.

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Pleased with this

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