Home
> Spitfire > Electrical Equipment > How far should wipers
wipe?
Anything and everything Spitfire.
Section : Electrical Equipment
Alternators, dynamos, lights, wipers, etc.
Posted By : Sarah Haley, 13-Feb-2006, 02:51pm
Please excuse my ignorance on this topic (as well as on the subject of SU carbs, see my other posts...) but The Flying Banana (1500) being my first
Spitfire, I don't really know how far across the screen the wipers should go. At the moment, they barely manage a 90 degree sweep (on the driver's side,
from 3 o'clock to 12 o'clock) and this makes the whole driving in the rain experience even more like driving a tank than usual.
I think it probable that I have the wrong wiper motor fitted, as this would be entirely consistent with the other mechanical bodges I am gradually
discovering...
Any clues would be gratefully received.
-
Posted By : Mark Astley, 13-Feb-2006,
03:00pm
Hi,
I think the sweep should be 135 degrees, 3 to about 10 ish on the drivers side, poor wipe might be due to worn gears in the motor or the end of the
drive cable where it mounts to the wheel. If the wipers reach maximum sweep then pause briefly before returning this points to probable wear,. Cannot
remember wether the drive wheel has the sweep stamped into it anywhere but someone else will know for sure.
Yours
Mark
-
Posted By : Chris Taylor,
13-Feb-2006, 04:16pm
The problem could be either the wrong components OR wear. Have you tried to see how much play there is at the wiper wheelbox by trying to move the
wip[er arm by hand with the wipers turned off. There will always be some play, but it should be perhaps 15 degrees?
The best giveaway for wear is if the wipers sweep further when the screen is fully wet compared with a dry screen, and also that the degree of
sweep is variable.
If you have the wrong motor, you probably need the right motor, (!) but you MAY find that there is more than one hole in the big drive gear in the
motor which will change the sweep. (The further OUT on the drive gear the cable drive is taken, the further the wipers will sweep). You also want
to make sure that nothing has come loose where the drive cable (rack) attaches to the gearwheel.
If (as is most likely) the wear is at the wheelbox (ie where the wiper blades mount to the spindles) you can make use of unworn parts of the rack
and pinions there. (This assumes that a previous owner has not already done this trick!!)
To do this:
1. Take the wiper arms off the wheelboxes. There should be a clip hidden underneath the arm which holds the arm to the spindle, then a straight
pull off.
2. Disconnect the rack from the drive gear at the wiper motor and pull the rack nearly all the way out. NOTE which way up the drive "nut" on the
rack is facing.
3. Once the rack is clear of the wheelboxes, turn each spindle through 180 degrees.
4. Turn the rack through half a turn so the "other" face of the "nut" is now uppermost.
5. Push the rack all the way back into the tube so it reengages the wheelboxes, and reconnect the rack to the drivegear in the motor.
6. Reattach the wiper arms.
Now you should have the unworn face of the rack engaging with unworn faces of the gearwheels in each wiper spindle.
If the arms are in slightly the wroing place, you can adjust the position by disengaging the rack at the motor and turning one way of the other
before reconnecting to the motor; this will reposition the wiper arms. Try to ensure that the end position has the rack "the other way up" from the
original position so it's unworn face is in use.
It is possible to buy new wheelboxes (I think) but you have probably got several years more wear left in the existing components!
-
Posted By : Ian Osprey,
13-Feb-2006, 04:23pm
When working on the mechanism, make sure the motor is disconnected.
The wiper motor is a powerful, vindictive beast
Don't ask...
-
Posted By : Colin Lindsay,
13-Feb-2006, 07:46pm
They should wipe until the rain stops...
Seriously, find the best sweep for your driving position - there's no point in clearing the lower portion of the screen, ie an inch off the
dashtop, if you are looking out of the middle portion. Many cars I know actually continue right off the screen and down over the chrome
finisher. If you have a limited sweep then adjust it for your best vision, often simply by taking the wipers off and repositioning
them.
Colin
-
Posted By : Van Hamlin,
14-Feb-2006, 06:08pm
Assuming you have the 2 speed wiper motor the correct wiper gear is 100 degrees. Identified by having 100 stamped on the metal side of
the gear.
If your wipers move too far then you probably have the wrong gear. The most likely wrong gear you will have is 110 which belongs in a
big Triumph saloon or most Minis. 105 and 120 also exist.
If your wipers dont move enough then it's probably due to excessive play in gears as Chris says but could also be the whole wiper motor
moving in its mounting.
If the wipers move significantly further when the screen is really wet then that's down to play or loose mountings. This is because the
windscreen is producing less resistance so the various bits aren't being pushed together and taking up the play so much. I don't know
if there is a wiper gear less than 100 degrees but it is worth checking what you have. It is quite easy to do because you can see the
number if you remove the flat cover of the wiper gear box and wipe away the grease. 100 wiper gear is available from Canley and
Rimmers.
Van