2002-2005 Rear Wiper Motor Part 2.....

Following on from http://www.landyzone.co.uk/lz/f10/2002-2005-rear-wiper-motor-part-1-a-217618.html

Well this evening I took the motor apart again to see what is what.

I took the mechanism out and replaced the cover, plugged it in, and the motor does indeed spin over.

I replaced the mechanism, but the motor work drive just grinds against the White Cog....the White Cog has been worn away with the years of struggle against all the crap that was found in it....

So, thinking of what can be done, I placed a couple of thin washers under the White Cog to raise it slightly so that the unworn edge of the gear teeth would engage with the Work Drive....

2002-2005 L322 Rear Wiper - YouTube
(Sorry it is dark, it was hanging by the wiring and illuminated with a torch!!)

So the Motor Drive will now turn the White Cog...great, but now as the cog is raised, with the crank arm attached the cover won't close....

Out with the angle grinder, I reduce the height of the crank spindle and pivot, the cover closes, but is still to tight as the motor just grinds the White Cog again.....

So I replace the cover lightly so it is held in place but not fully closed.....motor works and the spindle oscililates...

Put the motor unit back on the tail gate, off with the spoiler and replace the wiper blade...plug it all in and give it a test....

With the additional load of the wiper arm, the motor starts slipping on the White Cog again...no matter what I try the worm drive just keeps slipping....

So, annoyingly I know whats wrong and I know how to fix it (replace white cog) but I can't fix it.....frustrating

So no further forward.....thinking caps back on now!

buy a new motor maybe ?

then disconnect the washer and re-route out to its own spray jet so it doesn't feck up the motor again ?

Thought it'd be the cog from the photos, you can see the profile has been worn on the cog. Look for some part numbers on the cog to see if you can get a replacement from the manufacture?

Bix said:

Thought it'd be the cog from the photos, you can see the profile has been worn on the cog. Look for some part numbers on the cog to see if you can get a replacement from the manufacture?

Click to expand...

Take the plastic cog to a small machine shop with gear cutting facilities and get one made up in phosphor bronze

Rear wiper & washer
Just fixed my rear wiper and washer.
The rear wiper motor is a completely crap design. It has a hollow wiper arm spindle which is used to pipe water from the rear washer pump to the rear washer jets. The seal in the motor fails, the whole motor then gets filled with washer water and corrodes out the inside. Remove motor as detailed in this thread or look on youtube to find out how to remove the trim, wiper motor and rear spoiler.
The wiper motor is driven by the electronics pack fitted to the back of it. Inside here is a solid state relay with current sensing. If the wiper motor is even a little bit sticky and not yet seized this increase of current is sensed and it shuts the motor down.
With your wiper motor in hand, remove the torx screws, open it up and clean out all the crap. Grease it well and reassemble. With a soldering iron de-solder the wire from the electronics pack to the motor. Then connect the motor contact to a battery and an earth to the frame and the motor should then run. If all is OK the current will be <1 amp and it shouldn't sound too laboured.
Solder the wire back on and refit the motor to the tailgate. It should now run OK.
Remove the culprit of all this anguish, "the washer hose that goes into the back of the motor". There is a non-return valve in the hose, mine was blocked solid so clean it out, get a new one or toss it and do without.
On the left top edge of the tailgate is a blank grommet, pop this out punch a hole in it to take the washer hose. Route the washer hose through this grommet into the rear spoiler. I drilled a 10mm hole in the lower edge of the spoiler so I could route the hose through it and back out so that it sprays water on to the rear screen and not into the wiper motor.
Problem fixed.

Bloody hell, three years to come up with a solution.