Wiper Motor Repair

Revision as of 06:12, 8 February 2010; view current revision
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The Datsun 1200 windshield/windscreen wiper motor is very reliable. A 38-year-old unit was disassembled and no problems found. If the motor is still working, just lube the linkage, this will make it work well. However, if you wish to repair a broken one, here is how you can dissamble and inspect it.

Also see: 59-image photo gallery

Overview

These are the only tools you'll need: Flat and philips screwdrivers, 8mm and 10mm wrenches:

Removal

In the engine compartment, pull the connector apart. There is no catch or locking tab, just wiggle it straight apart.

Go into the cabin, on the passenger side, and look under the glove box for this cover:

Remove these four screws on the firewall:

This will expose the motor shaft and passenger-side linkage

Pop the clip off the linkage with a flat screwdriver

This is where to lubricate the linkage:

The ball-end needs lubrication inside and out. Roll grease in as you would do a wheel bearing.

Now that it is disconnected from the inside linkage...
Remove the three 10mm screws holding it to the firewall.
Then pull/pop/wiggle it loose, as the rubber tends to stick after 30 years...

Tilt the motor so the shaft linkage clears, and remove from the firewall

Be careful not to lose any of the three rubber mounts.

There are only three, although there are four holes in the motor bracket.

Cleaning

15 minutes with a toothbrush and a spray can of ether will get it generally clean. This is important so that when you open the motor dust and grime will not contaminate it.

Be careful not to drop it, or you may break the connector like I did:

Disassembly

Remove the 10mm nut and washer from the shaft and wiggle the arm off

Break the three large philips-head screws loose with a Vice-Grips, then remove them with a screwdriver

The bracket and large shaft seal comes off

Remove any rust from the shaft, as it will contaminate the bushing later on unless cleaned

Remove the three gearbox screws.
Then, flip the cover out of the way to reveal the gears

Don't lose the plastic gear end cap (arrow)

Remove the two 8mm nuts holding the motor housing to the gearbox
Then pull the motor from the gearbox

The brush assembly stays with the gearbox

Inspection and Lubrication

Pull the motor armature out of the permanent-magnet housing

Carefully wipe dust out of the housing (turn upside down, so that dust doesn't fall into the end bushing).

Put a small dab of grease in the bushing.

Note there is a small felt wash either in the bushing, or it may come out with the armature. Don't lose it.

The armature is a precision-balanced assembly. The shims are for balancing. Don't attempt to remove them.

If the brushes are still long (as in photo), no need to replace them.
pull them back against the spring, and hook the wire around the guide to hold them.

Then put a dab of grease in the gearbox shaft bushing.