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My wipers parked "off screen" in the right position (which is to say not really off screen, just at the bottom of it), but the "on screen" parking positon (used when they're stopped during intermittent wiping) was too high, and worse, they overran the windshield a bit on full stroke, claking in to the chrome window trim.

I read up on them in the workshop manual, but it only states how to fix some other issues. I also found a scan of the Lucas manual for the wiper motor/gearbox on, which helped a bit.

Anyway, here's what I did:

I removed the strap holding the windshield wiper motor to the bulkhead.
Loosened the 3/4" nut where the wiper gearbox attaches to the drive cable (right before it goes in to the bulkhead).
Rotated the wiper motor/gearbox assembly around until the motor end was leaning against the fender.
Tightened the 3/4" nut.

You can now see under the gearbox where the on-screen parking switch is mounted. It has two slots in it, with a small phillips-head screw in each. By loosening them you can slide it back and forth to change the parking position. Note: there's also an off-screen parking switch at the back-end of the gearbox (toward the front of the car), but there are no screws in its slots (it's attached from the inside of the gearbox and is not adjustable).

I loosened the two screws and nudged the on-screen parking switch about 1/16" to 1/8" toward the bulkhead. Oddly enough, this affects the off-screen park position more than the on-screen one. (The offscreen park position is controlled by how much travel is left on the cam when the motor reverses -- so if it parks on-screen later then it parks off-screen earlier.)

If you move the on-screen parking switch too much, then it won't reverse and park when you turn it off from intermittent wipe. Note that you only need to move it a little to make a big difference. I'd suggest starting with 1/16" movements and see how you get on.

At the end of my adjustments I now had all three positions (off-screen park, on-screen park and full-wipe-extent) too far advanced. So I removed the wiper arms from the pivot studs, rotated them to a better position, and put them back on. (There's a little clip between the wiper arm and the pivot stud nut that you need to push up with a screwdriver to release it from the groove in the pivot stud. I found that helpful bit either in my TR4 workshop manual.)

Don't forget to loosen the 3/4" nut and rotate the wiper motor/gearbox back and reattach the bracket. I had to go through the whole process twice as rotating it back changed the setting a little bit and it stopped parking. It is a little fiddly, but you should be able to get a good setting after a couple of go's.

-- Jeff.
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