Floppy Wipers

Post by **mof** » Tue Sep 23, 2003 9:42 pm

Half of my driver's wiper arm flops off the side of the screen on the up stroke and both wipers slam noisily into the bottom of the screen on the down stroke. I KNOW I've seen a bit in a Tech article in an old copy of Minor matters, but now I cannot find it.

Does anyone out there know how to reduce the effective stroke of the wipres?

Note:- The blades park fine, it's the swept area which is too large.

Please help, I'm going potty.

Post by **Scott** » Wed Sep 24, 2003 5:04 am

mof,
This is usually down to wheel box/cable wear.
Do the wipers only travel too far while driving at speed ? If so then this is wear & wind pressure blowing them off the screen edge.
Wear can be cured by rotating the inner cable 180degrees to use the unworn section & also rotating the wheel box shafts 180 to use their unworn section.
If they do it all the time then something is wrong with your wipers set up. Have you changed the wheel boxes or motor recently ?
I think 1000 wheel boxes might be slightly different for opposed wipers versus parallel wipers.

Post by **mof** » Wed Sep 24, 2003 9:17 am

Scott

This happens even when stationary. I think you are on the right lines here, as the article I vaguely remember did talk about turning something round through 180 degrees! It's a 1970 1098cc, which I have owned since 1984, so I suspect the box is original. I have some experience inside the box, having had to clean up the segmented brass plate during a period of erratic blade parking. I take it from your reply that I am looking at mechanical wear on the gears which drive the inner cable. Could you just talk me through what I should be doing please.

Cheers

Steve

Post by **ColinP** » Wed Sep 24, 2003 12:41 pm

mof,

I'll jump in with what I did - and Scott can correct me when I get it wrong...

1) remove wiper arms, blades

2) open bonnet, and find the wiper motor. Mark the orientation of the top cover to the body (so you can get the correct parking position of the wipers afterwards).

3) remove the cover plate on the wiper motor box, ane loosen the tube containing the rack from the motor.

4) remove the rack end (it's solid square shaped rod) from the pin on the large cog wheel, marking the top side of the rack.

5) Now gently pull the rack from the tube, and mark the wiper spindles with arrows. Then turn the spndle to invert the arrow.

6) At this stage I cleaned out all the old grease from the motor and the rack, and re-greased it all (messy).

7) Gently insert the rack back into the guide, making sure that the old top of the rack faces down, you may need a gentle wiggle to get the spindle pinions to re-engage (either the rack or the pinions).

Put it all back, and switch on the wiper motor and adjust the parking position.

Luck,
Colin

Post by **Willie** » Wed Sep 24, 2003 9:34 pm

While it is disconnected you should rotate the wiper blade
spindles through 180 degrees too! Thus bringing the unworn
teeth into engagement with the rack.

Post by **mof** » Wed Sep 24, 2003 11:02 pm

Thanks lads, I just KNEW there had to be more sufferers or ex sufferers out there! I wait with interest to see what Scott comes up with. I wonder if the fix is the same below the equator. Or am I getting confused with plug holes?

Post by **Scott** » Thu Sep 25, 2003 5:45 am

We don't usually need this fix down here as it hardly ever rains. I can't even remember the last time I used my wipers. The problem we have here is the wiper blade sticking itself to the glass from lack of use.

It doesn't sound like a wear issue if it happens even when stationary. Normally if the wear is very bad, then you have a reduced sweep when stationary but a larger one at speed on the road (unless your wipers are unusually fast).

Is this a new problem or an ongoing one ? If an ongoing problem then you might have to start looking at the sweep angle stamped on the plate fixed to the large gear inside the wiper motor. The pin that the inner cable (rack) mounts to is in slightly different locations depending on the sweep angle. I dont know the correct angle for a 1970 model but someone at your end should be able to tell you from an old one (or even their one).
If the wiper mechanism is worn, you should be able to move the arms up & down quite a lot on the screen. Remember, it only needs a very small amount of wear in the mechanism affect the wipers as this is magnified greatly at the end of the blades (1mm at the rack can quite easily become 2cm at the wiper blade).

Referring to

Does anyone out there know how to reduce the effective stroke of the wipres?

The only way to do this is by changing wheel boxes to a different geared type (larger gear) or by altering the rack drive pin (closer to centre).

Whats wrong with our plug holes ? The water goes down normally here.

Post by **mof** » Thu Sep 25, 2003 9:35 am

Scott

This car had a bodged crash repair at the front nearside corner some time in it's history. I wonder if they replaced the wiper mechanisms with the wrong ones? I strongly suspect however that this is likely to be a wear and tear issue. I'll let you know how it goes. I supose your Moggies don't rust either?

Steve

Post by **57traveller** » Thu Sep 25, 2003 11:18 am

Further to ColinP's excellent description and as a visual aid, the two black lines represent the marking to be made prior to removing anything on the gearbox (paragraph 2). The red arrows show the four (or are there sometimes 6?) hexagon head screws that have to be removed before removing the cover and then disconnect the tube by removing the union nut marked with the green arrow (paragraph 3)
The domed part of the cover is moveable and adjusts the wiper parked position so it is important that this is marked relative to the flat cover before removing anything.
Too many "removes" but what the heck!

Post by **ColinP** » Thu Sep 25, 2003 1:17 pm

57Traveller,

thanks for the photos and woderful comments. I wish my car's engine bay looked as good as that! I also wish I could take piccies of the work in progress - our digital camera is too new to cover with engine oil/grease etc....

I made the mistak of not checking where the wipers parked, so the first time I switched on afterwards I wiped the bonnet with the new blades and arms I'd just re-fitted...........

Colin

Post by **57traveller** » Thu Sep 25, 2003 2:36 pm

Yes Colin, I would suspect most of us have done similar

Not just with the wipers either!