Wipers - any ideas?

[spunkymonkey]

The wipers on our Daf have a couple of problems. First, when you turn them on, the initial movement is "down" - they're parking before they reach their lowest point. That should be adjustable by repositioning the crank arm on the motor (it's held on a tapered spline), so not too worried about it.

The second one is a little more of a problem. the swept angle only just reaches vertical in front of the driver. It's supposed to have a 110 degree sweep but is only sweeping about 90. It's likely to be an MOT problem as they only clear enough for the driver to see out of their left eye!

There's no play in any of the linkage and the only thing I can see (from a geometry point of view) that would affect it is the length of the crank arms - these are not adjustable.

There is one adjustment, in the linkage from the motor crank to the driver's wiper. According to the book, this link should be set to 148.5mm between centres. This is quoted as the same for all models.

But the book shows the older (rectangular box type) wiper motor, mine is the cylindrical shaped one. More to the point, the maximum length of the link on mine is about 135mm - it's literally impossible to set it to the 148.5mm quoted.

If anyone has any info on the wipers specifically for a 33 with this motor (perhaps a service bulletin?) I'd be really grateful. Otherwise I'm going to have to get creative.......

[daf44]

hi joe.

can't help with the wipers i am afraid as mine is a 44 and i think it is differrent. i have complete confidence in your abilities to sort something out.

nice job on the rack though. i had not thought of a cutting board for nylon.
i have just got a lathe myself and find boot sales good for nylon. dead screwdrivers with nylon handles are a few pence each and give a nice size piece of nylon to work with. i have also found a few old brass weights in the boot sales for a few pence giving me some nice brass stock 1.5 inch diameter and just under 2 inches long. well worth the trip.

good luck and happy hunting.

paul44

[spunkymonkey]

That's no problem for adjusting where on the screen they sweep, John - the problem we have is how much of it they cover - if I adjust so that they sweep right across in front of the driver then they never get close to the bottom and, if I adjust so they reach the bottom, they only wipe half the driver's view!

Looked again at the geometry, and I think that altering the length of the link from the motor to the wipers will make a difference - longer should give a greater angle of sweep up to the point where it's too long and jams it solid - but it certainly can't be adjusted to the length that the books quote. The Autodata and official books agree on that length (I guess that Autodata got it from the official manual) but it's based on a slightly different linkage

I suspect it's going to be a case of play and see. Any solution will obviously be reported back

[spunkymonkey]

The linkage from the motor to the wipers is adjustable on this one, John - it's a flat steel link in two parts, bolted together in the middle. One half is slotted, giving adjustment from about 124 - 139mm between centres. Need to get to the car and measure the distance between the motor spindle and the nearest wiper spindle centres - from that it should be (fairly) simple geometry to work out the right length for maximum sweep angle.

But the access is, as you say, terrible - even with the instrument panel out

[starider]

:)Hi,have looked through the 33 service bulletins and can only find one dated 2nd May 1966 "effective at chassis no.148500 the short wiper motor link is adjusted to a length of 147mm, thus improving the field of vision"[this was during the 32 run of cars and I remember the 33 were produced with a different type of motor].I also remember having to tighten the pinch bolt on the sliding halves of the short rod and adjusting the length on a 33 under warranty,and it's a pig of a job.According to the Eindhoven workshop manual the sweep angle is 100degrees and the angle of the blade to the arm is 16degrees.I don't know if any of this is of use but I have "trawled" through the service bulletins. starider.

[spunkymonkey]

Thanks, Starider - that at least confirms that changing the length will change the swept angle Unfortunately, you're right about the different motor on the 33, and the flat link with pinch-bolt won't adjust out to 147mm. If that was an ammendment to the original 148.5mm, and improved the sweep noticeably, then it sounds like it may be quite critical around the "right" length!

[starider]

:)Hi again, I would expect that a small amount of adjustment on the small linkage would make quite a large difference to the swept area.My hazy memory of around 36 years ago tells me I spent a long time adjusting the linkage on the warranty claim, cannot remember how much stripping down I had to do to get at it!!! anyway good luck with the adjustment. starider.

[spunkymonkey]

As far as I can tell it's the right parts, Mac. As the photo shows, it's pretty specifically shaped to have come from something else:



I've been doing a few scale drawings and it looks like the exact geometry doesn't matter - a longer link will give a wider sweep up to the point where it becomes too long and "locks out" because the link is longer than the max distance between the cranks.

With the (known) crank lengths that gives a max sweep of about 115 degrees so 110 sounds about right for safety in use. If it does lock out then, in fact, the motor will force itself past that point by flexing its mount or the scuttle where the wiper shaft goes through.

So it looks like setting will go something like this:

1) Park motor and fit link at the max length it will fit, with the pinch bolt slightly loose.
2) Shorten link by a millimetre or two and tighten bolt.
3) Hope for the best. ;D

[spunkymonkey]

Well, it'd save a few trips to the car wash Looking at it, didn't think it could quite go that far but certainly one to look out for during the trial & error bit!

[spunkymonkey]

For reference, having got the wipers giving correct sweep, the best length for that flat link seems to be 131 mm measured on the "shorter" side (because of the twist in it, you get about a 5mm difference in measurement between centres depending which side you measure!)