Wipers hit the rubber windshield gasket when speed is over 40 mph

[Mike Shumack]

This problem has been with the Coach since I bought her - but its not been on the top of my to do list since I don't drive in the rain often. On my last trip it rained so this issue has moved back to the top. 

Problem: When I'm driving under 40 mph the driver's side wiper arm sweeps normally from its horizontal rest position to the vertical position (90 degree sweep). But when my speed is over 40 mph the wiper blade hits the rubber windshield gasket in the vertical position and that makes a loud annoying slap sound. The wiper arm sweep is more like 95 degrees when driving over 40 mph. This problem is only with the drivers side wiper blade.

Its hard to troubleshoot because it doesn't hit anything when running the wipers with Coach stationary (while spraying water on the windshield). I can't find any slop in the mounting or linkage and the wiper arm is not slipping on the shaft.

It sure seems like something is flexing due to the added "wind force" on the blade when driving 50 mph+ , but I can't find anything loose or flexing. With the wipers off, there is no flex in the arm/linkage. Maybe previous owner replaced the wiper arms with the wrong part - but then I would expect the blade to hit all the time.

I repositioned the blade a couple of different ways but cant find a spot where it wont hit either the bottom edge of the gasket or the A-pillar side of the windshield gasket.

For now, I'm going to replace the 28" wiper blade with a 26" blade. I think that will "fix" it for now.
Has anyone else had this problem?

[Fred Brooks]

   Mike,
Some of us have added these assist springs to the arms to increase blade tension against the windshield. Works fairly well at speeds above 40 MPH.
  https://www.iowa80.com/gift-guide/stocking-stuffers/black-windshield-wiper-snuggie-pr-42959?gclid=CjwKCAjwhaaKBhBcEiwA8acsHF2Dc3JZwA0aRkbaQqk0QaQpfoKPSbYeLlwZJ3kvx62U964tixZAlRoCB6AQAvD_BwE

[Eric Maclean]

Mike
It's not uncommon for the wind to change the sweep of the wiper travel it is usually caused by ware in the linkage but you say the isn't any perceivable slop in the linkage .
The only suggestion I can make is to move the wiper arm on the spline at the pivot one spline to see if it helps but as you say what you gain on one end of the travel you loose on the other.
Maybe measure the wiper arm length to see if someone has replaced it with a longer arm ( it's surprising how much difference a half an inch makes it the total sweep)
I assume it's a pantograph type wiper arm in which case there is an adjustment on the smaller link in the arm to allow for a parallel adjustment to the centre windshield rubber .

If as you say the system is sweeping through more than 90 degrees the only thing that can cause that is the linkage geometry or ware of the linkage unfortunately those linkages are hard to see or even get to.

Eric

[Bill Lampkin]

Mine made the same noise; My wiper didn't hit anything, it just made the noise. Shorter blades fixed it (24"). I think the noise is coming from the linkage somewhere, not from actually hitting the windshield gasket.

[Mike Shumack]

The only suggestion I can make is to move the wiper arm on the spline at the pivot one spline to see if it helps but as you say what you gain on one end of the travel you loose on the other.

If as you say the system is sweeping through more than 90 degrees the only thing that can cause that is the linkage geometry or ware of the linkage unfortunately those linkages are hard to see or even get to.

Eric

I tried moving the arm on the splines. One spline is all I can move else it will hit the bottom of the rubber gasket. My blades also have a rotational adjustment where the blade attaches to the arm - but that either makes the blade hit the side of the gasket of the bottom of the gasket depending on which way I rotate it. There are also two holes in the blade, one about center the other about 1/4 off center. I tried both.

The issue has to be slop in the linkage. It feels pretty tight just trying to move the arm with the wipers turned off. Maybe the slop only shows when the wiper arm is full left.

[Mike Shumack]

Mine made the same noise; My wiper didn't hit anything, it just made the noise. Shorter blades fixed it (24"). I think the noise is coming from the linkage somewhere, not from actually hitting the windshield gasket.

I'm going with the shorter blade fix. I ordered a 26" blade from AM Equipment, for the drivers side. About $13 with free shipping. The passenger blade is 28" and has no issues so I'll leave that alone.

For a while I want sure if it was actually hitting the gasket on the A-pillar side or if it was just noise from the linkage - but after messing around with the blade angle, I can see it is definitely hitting on the bottom edge now when the blade is at full left sweep. But I may have caused that myself by messing around with it. I'll know for sure once I install the 26" blade. If it still makes the slapping noise after installing the new shorter blade - then it's back to square one.

[Christian Fish]

I second Fred’s suggestion. Mine did the same thing when I bought it a year and a half ago. I replaced the blades and added snuggies (suggested by BCS) and haven’t had the problem since

[Bill Lampkin]

Do a search for my post "wind whips windshield wipers" from 2 years ago. In it is a link to AM equipment and their options for new wiper assemblies. I'd like to see how their pantograph wipers would work! Two things on our coach that are woefully inadequate-wipers and headlights.