Wipers - hitting the windshield frame

[lrover109]

I have adjusted my wipers for what seems like 100th time on my nada 109 so thought I would ask
My wiper blades hit the windshield frame every 2nd or 3rd sweep when it rains hard -live in Oregon so more than an occasional occurrence - dry or light rain they work fine and they always park back to where I set them
Any ideas on how to adjust so I don't have to listen to the whack whack of the wipers?

[stomper]

Early Series IIa, or later IIa, or series III?

[lrover109]

It is a 67 NADA 109 - so later single motor

[cnfowler]

How are you adjusting them? Taking the wiper arms off the posts, cycling the motor, then replacing the arms?


Colin

[lumpydog]

For the 67 single wiper motor, adjustment is really limited to:

1) Where the wipers park
2) Where the wipers sweep

With regard to park, there is a "dead spot" that cycles through the circular motion of the engine. When you turn the wipers on, the dead spot is electrified and the wipers sweep through their range of motion. When you flip the power switch off, the when the dead spot is reached (no power), the wipers park. On the motor their is an adjustable cover that determines where the dead spot is.

With regard to sweep, as Colin points out, you can adjust by taking the wiper off it's splined mount and moving them left or right a few splines until they cover the desired area.

If you are having random oversweeps (hitting the frame), then look at the wipers wheel boxes (I think that's what they're called). Basically where the wiper's teeth engage with the wiper rod that cycles back/forth. Check for damaged or missing teeth - to a damaged rod.

[lrover109]

Yes - and they park fine. It almost seems like with low friction - when the windshield is really wet they hit the frame with light rain / dry glass they stop cycling where they park. I was thinking that there might be some restriction that is catching the drive line creating some additional torque that drives the blade that extra inch down. The drive line looks pretty well lubed - although I have not completely pulled it out.