Wiper motor...again!

[John]

I'm getting fed up with the factory windscreen wiper set up on my 1986 SE. I rebuilt the motor some years ago then last year the drive cable snapped so that was replaced, now the wiper arm has swept onto the bodywork!

I took the wiper arm off to check the spline wasn't slipping, seemed good so refitted it. It was fine for a few sweeps then made some odd noises and stopped mid-sweep. Took the wiper off and the spindle sweeps as it should as long as there's no load on it.

I'm thinking the cable must be binding, causing the wiper arm to stall, but the fact it went onto the bodywork suggests it has jumped the cog on the wheel box and got out of synchro. When I fitted the new cable I made sure I rotated the spindle cog 180 degrees so it presented fresh gear teeth to the cable. The wheel box nuts were loctited so they shouldn't have come loose.

I know I'll have to take the motor and it's drive out of the dash again, I'll post an update once the cause is known, but I'm considering an upgrade to something better engineered. Any thoughts? I have nothing against Lucas, I like the fact you can take the motor apart and fit new brushes and park switch, and replace the cable. But the way the assembly is fitted to the car is a joke. The factory tried to improve things by adding a bracing bracket to the wheelbox but it's completely inaccessible once the dash is assembled.

Has anyone installed something better, or successfully modified their standard wiper set up?

Cheers

John

[bash]

Is the spindle free ? I know you have tested it with the arm off but the spindle itself has a tendancy to seize up and could be causing your problem. An easier check than removing the whole assembly would be to remove the instrument panel leave the wiper arm off and then undo the nut on the motor to rack and see if you can pull the rack in and out a short distance, if you can't that may be your problem. I could of course be completely wrong....again

Bash

[MetBlue]

When I fitted the new cable I made sure I rotated the spindle cog 180 degrees so it presented fresh gear teeth to the cable.

Only 3 components so full removal will soon find the issue I'm sure.
Good plan to turn the wheel box, but only worked if PO has not already played that card .
My monies on you needing a new wheel box. I think it's also possible to spin the cable drive 180 Deg.
Tony

[John]

Thanks for the replies. I know people have posted on here before about replacement wheel boxes, I'll check to see if they managed to find new ones that match our spec.

Cheers

John

[MetBlue]

SJ sportcars stock them. I had one a couple of years ago. It's been fine since.
The old one was in a right state. Rust around the spindle made it very tight and clearly had been the cause of water getting inside the car for a good while.
Tony

[John]

Thanks Tony, I think a new wheelbox should fix the problem. I got the motor assembly out of the dash today and the wheelbox cog teeth are shot, even the ones that were good when I fitted the new cable last year. I think the cable has been moving off the cog teeth, the curved part of the wheelbox casing just doesn't hold the cable in contact with the teeth properly. I'll order a new box from SJ, it'll be interesting to compare old and new.

Cheers

John

[John]

Update on my wiper problem. Got a new wheelbox from SJ and it's sorted the problem, the old one not only had damaged teeth, the cable was not held close enough to the gear cog - damage to teeth then eventually the cable jumped the cog and things got out of synch.

I wanted to fit a new spacer, part number B089M0418F. This goes on the spindle shaft and acts as a spacer between the wheelbox and the body. Nobody appears to stock them, so I made one out of neoprene sheet from a boat chandlers. It came in a small roll, 2mm thick, so I cut 35mm square pieces, stacked up 10 of them, sandwiched between some wood, then drilled to give a 16mm hole for the spindle.

This worked really well and is a solution I would use again for making seals and gaskets that are no longer available. The sheets are probably available in different thicknesses as well. I'll post some pictures in the next few days.

Lessons learned;

Don't just rebuild the motor, do the cable and wheelbox at the same time.
Remember you can fit the wheelbox the wrong way round - I did this, twice! What happens then is the wiper arm tries to arc to the left not the right. Best to take a picture of how the box sits on the cable ferrules before dismantling the assembly.
Renew the wheelbox spacer and the motor to body rubber pad. Both were shot or missing on mine, and the motor and rack assembly was moving around.

Cheers

John

[Alan_M]

I wanted to fit a new spacer, part number B089M0418F. This goes on the spindle shaft and acts as a spacer between the wheelbox and the body. Nobody appears to stock them, so I made one out of neoprene sheet from a boat chandlers. It came in a small roll, 2mm thick, so I cut 35mm square pieces, stacked up 10 of them, sandwiched between some wood, then drilled to give a 16mm hole for the spindle.

This worked really well and is a solution I would use again for making seals and gaskets that are no longer available. The sheets are probably available in different thicknesses as well. I'll post some pictures in the next few days.

Cheers

John

For this spacer I used a rubber suspension ball joint boot. This sealed well and as it came down over the top of the wheel box it would help protect it from any water that does make it in. I always keep a pack of various sizes.

[John]

Great tip Alan, that will come in handy for future jobs I'm sure. Here's a few pictures showing the neoprene layer cake approach;

Old and new wheelboxes, the old one wasn't clamping the cable ferrules properly, but more importantly there was too much clearance for the cable - that's what chewed the gears up


Drilling out the 16mm hole in the neoprene




The finished spacer


Just got to get the steering wheel back on, and noticed that the splined boss is cracked

My original boss was cracked, I replaced it with a decent used one a few years back from Lotusbits, so I'm thinking the lack of power assistance on my system at present is putting a strain on the wheel boss. 40 year old splined alloy versus steel. Anyway, I'm going off topic, that will have to be the subject of another post I think!

Cheers, John

[TonyL]

Thanks for the write up & the pictures, John. This job is on my list, & I'm not looking forward to it.

[Lotus-e-Clan]

Top tip on the DIY seal alternative! I'll be using that one for sure on various repairs!

[John]

Thanks guys, the advice given on this forum has been a massive help to me over the years, I'm glad to give something back now and again.

Tony, I've had the wiper motor out of my car several times now and the first time I struggled with getting the two 10mm nuts off the motor bracket - even harder getting them back on again. I got one of those socket drivers with a flexi shaft, they're fab for jobs like this where space is tight. I also used some grease in the socket to stop the nut falling out on re-assembly. The stud on the left hand side is a swine to reach, and I found the flexi drive made life easier.

Another thing I didn't do first time - unclip your speedo cable before taking the dash out. It should be clipped in two places to brake pipes, I didn't unclip mine first time round, and unscrewing the speedo cable retaining nut wasn't as easy as it should have been. Unclipping the speedo cable means you can pull the instrument panel forward a few inches further for better access.

Cheers

John