Wiper wheel boxes

Today I got the screen jets working and checked the wipers for correct orientation. The wipers only wiped 90 degrees then sometimes wiped the full screen. I noticed on the drivers side the conduit was moving with the inner drive cable backwards and forwards about 10mm thus the wipers were loosing traction. I have just replaced all the dashboard! I see in the manual the flared end of the conduit should engage with a slot in the wheelbox fitting. Is this the slot cut into the wheel box cover? The passenger side is not in the slot but is a tight fit between the two wheel boxes but the drivers side maybe needs holding at the wheelbox to stop it moving? The manual does not make it clear.

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Yes, the flares must be locked into the slots in the covers. These racks work the same as all Bowden cables, i.e. they depend on both ends of the outer sleeve being anchored.

It is a pity the facia panels are installed as these boxes are only reasonably accessed face on. If you can get visual and physical access, can you determine the cause of the unclamped tube? Is there a loose or missing screw; is the cover bent; is the flare damaged; etc.

If you have to remove the facias, there is then a prime opportunity to give the whole rack system a good service so that it won’t give you a problem again before you die. (You may be fully familiar with this detailed description but I don’t mean to bore you.)

  1. Firstly check the amount of backlash in each arm. Move each arm gently back and forth by hand in the park, sweep centre and full sweep positions. The last two are done by switching the wipers on, then turning the ignition off at each position. If wear is minimal, the backlash should be equal and small. Sometimes with excess wear, the arms ‘flop’ at the end of each stroke. If you think there is a wear problem, this might be overcome as explained below.

  2. Return the motor to the park position, then remove the arms and put a felt pen mark on the upper half of each drive hub, from the centre vertically to the upper edge.

  3. Disconnect the rack from the wiper motor gearbox crank arm. Push the rack back and forth by hand to feel the resistance or amount of drag in the tube. Unreasonable resistance can be due to dry lubricant, no lubricant, excessive bends or a damaged tube.

  4. Carefully draw the rack completely out. The wiper arm drive hubs will roll around as they follow the rack. Take a note of where the pen mark on each hub is pointing to aid in the reassembly.

  5. Clean the rack and re-grease before refitting - after all other work to come is done.

  6. Remove the wheel box covers and clean out old grease. Check if the wiper shafts can be slid up and down freely. There should be no resistance to sliding or full circle rotation. The shafts then should be lubricated.

  7. Grease the gear wheel teeth liberally and refit the covers a bit loosely, ensuring the rack tubes are seated and held in the cover grooves.

  8. Check the orientation marks on the hubs when the rack was first removed, turn them a half circle for the new starting position, then carefully feed the freshly greased rack right through. You may have to fiddle a bit but when the rack is fully seated and fitted into the wiper crank arm, you should see the pen marks are now pointing down, i e turned 180° from the original prestart setting. This now engages the rack with an unworn section of the gears. If they are out a bit, you can redo the start setting for the hub. Remember that only about a third of a circle is used for the sweep function so a few teeth out either way doesn’t matter.

  9. Tighten the wheel box covers and try the rack by hand. If all is well, finish it and test with the wiper motor and blades. Anything that reduces friction means the motor doesn’t work as hard and does not run as hot.

Job done - time for a tea. Good luck!

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Thanks for the concise reply. I have just resolved the problem this way -
The two wheelbox cover bolts can be loosened without removing the dash but you cannot reach to actually take them out of more importantly get them back in. I undid them as far as I dared and then I could move the outer cable and it gave enough clearance to push the flared end under the cover and into the groove. I tried a screwdriver to move it but then found by moving the wipers by hand the outer cover moved into position and then I simply tightened up the bolts to secure it correctly. Wipers now wipe across the screen although I could do with a ten degree move to the offside to make them perfect?
I also greased the boxes using a screwdriver while I was there. Took less than 15 minutes to fix without removing the facia.
Hope this helps someone else.

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