Ok, so I rebuilt my two speed wiper motor - all nicely greased up with new bushes and motor brushes and fitted those luvly new heavy duty wiper arms and blades from Minispares.
The motor and wipers work superbly but.............there is too much arc now, i.e. the wipers blades fall off the screen and over the screen seal at both ends of the arc. At first I thought I'd got the wiper arms fitted incorrectly but now I realise I have too much arc. How can I reduce it back to what it was (when using the old DR3 one speed motor)? Is there a gear with a reduced angle or is it possible to bend the arms a bit?
The car is a Mk1 with RH rest by-the-way
Ahhh! Thanks!
Where can I get one from?
I'm sure the sweep on the new gear says 110degrees.
Does this mean I should be looking for a 90, 95,100, 105 ?
What would've been the sweep angle on my original DR3A single speed?
rich@minispares.com wrote:i guess your using mk1 wiper boxes with the small cogs and a mk3 motor?
im sure this combo just about pulls the wing mirrors of as it has so much sweep!
i think (dusty recess of mind ) that you have to use the 120deg cog from a mini van rather than the normal 110deg cog and this makes it far better
trouble is, you have to find one!
Indeed it does.
So I have to find a scrapyard Mini van 120deg wiper gear wheel do I? Anyone? There'll be a drink in it for you!
P.S. if I need a shorter sweep, how is 120deg shorter than 110deg? I don't understand
Well, If I was selling them and you asked me, I'd say you would need to buy one of each size and try them all.
Have you tried measuring the angle of the sweep at present? Its awkward to do, but I've noticed that over time, wear in the system tends to increase the sweep. You might find that just fitting new parts with the original angle is enough to solve the problem.
Tim wrote:Well, If I was selling them and you asked me, I'd say you would need to buy one of each size and try them all.
Have you tried measuring the angle of the sweep at present? Its awkward to do, but I've noticed that over time, wear in the system tends to increase the sweep. You might find that just fitting new parts with the original angle is enough to solve the problem.
Tim
That makes a lot of sense, although with new wheelboxes at 35 quid a pop (+VAT), I'd be tempted to change the rack first (£7.25+VAT). Is it worth changing just the one item(s) or would that be a waste of time?
<EDIT>
Just been out to the shed! And as Alf Tupper might've said, "Bloomin' 'eck!" It appears that I have managed to invent a wiper system with approximately 170 degrees of sweep. Is this a new World Record?
Rich and Tim are right - I might have to start at a 90 degree gear/shaft and work my way up!
Mk1 wheelboxes have 22 teeth, while the later ones for use with the 14W round-body motor have 32 teeth
If you have a 14W motor with a 110 degree gear then this will give 110 x 32/22 = 160 degree sweep with the Mk1 wheelboxes
To reduce this to a 110 degree sweep you would need 110 x 22/32 = 75 degree drive gear, but the smallest 14W drive gear
angle is 90 degrees, which would give a 131 degree sweep with the Mk1 wheelboxes.
You might get away with this, as early Mk1s had a 130 degree sweep, but this was reduced to 120 degrees after a few years
Otherwise, you will have to change to the 32-tooth wheelboxes to get the correct sweep.
Mk1 wheelboxes have 22 teeth, while the later ones for use with the 14W round-body motor have 32 teeth
If you have a 14W motor with a 110 degree gear then this will give 110 x 32/22 = 160 degree sweep with the Mk1 wheelboxes
To reduce this to a 110 degree sweep you would need 110 x 22/32 = 75 degree drive gear, but the smallest 14W drive gear
angle is 90 degrees, which would give a 131 degree sweep with the Mk1 wheelboxes.
You might get away with this, as early Mk1s had a 130 degree sweep, but this was reduced to 120 degrees after a few years
Otherwise, you will have to change to the 32-tooth wheelboxes to get the correct sweep.
A golden nugget(s) of information. thanks very much!!
Is there a gear with a reduced angle or is it possible to bend the arms a bit? 
) that you have to use the 120deg cog from a mini van rather than the normal 110deg cog and this makes it far better
