Mechanics

FRONT WINDSHIELD WIPER MOTOR

2002 Subaru Forester

Noises problem
2002 Subaru Forester 4 cyl All Wheel Drive Automatic 109000 miles

Front windshield wipers travel too far - intermittently but most of the time. This started after snow was allowed to pack up under the wipers and I suspect something was stripped or damaged, although this doesn't happen all the time.
The driver's side wiper travels so far that it hits the post with a loud " whack" and both continue downward on the opposite stroke until stopped by the cowl cover.
I noticed that there is a lot of play in both arms. When in the " off" position - all the way down on the cow - I can easily move the wipers up to what I would expect to be the normall lowest or " park" position at which point I can't move them in that direction any more. I estimate there is 4 or 5 inches of travel at the tip of the wiper, maybe 15 to 20 degrees of arc. Should replacing the motor take care of this?
Also, I haven't been able to remove the arms from the shafts. Do I need a puller of some sort to do this? My manuals just say " remove the arms" as though they should come off easily.

Thanks
Avatar
Rlgates2
October 30, 2009.



You need to see what is moving and what is not. IF you move the arms and can get a glimpse of the transmission, look for movement.

And pop off the arms and clean up the posts and resucure the arms to the pivots. The the transmission moves, disconnect the transmission from the motor and feel for play in the wiper motor.

Post back if you need anything.

I disassembled the cowl and found very little play in the transmission. I'm taking the " transmission" to mean the long arms that transmit movement from the motor drive shaft to the wiper arms. I replaced the wiper motor and there is absolutely no change.

The problem is intermittent. One stroke is normal, the next whacks against the driver's side windsheild post and then literally bounces off the cowl on the return stroke. It seems more likely to do this, and hits both ends of the stroke with greater force, when the windshield is lubricated with rain. When I first installed the new motor, I thought I had fixed the problem because I ran the wipers for quite awhile (windshield dry), and they seemed to work normally. What is supposed to stop the stroke at each end? It seem s to be the frame of the car at this point, and I know that's not right.

Is there an electronic control that tells the motor how far to rotate, or is this a purely mechanical system?

Thanks.

Tiny
Rlgates2
Dec 7, 2009.
So you felt play in the motor shaft before you replaced it? Was that the reason?

Have you pulled the wiper arms off the posts yet?

If the nut is not tight or the ribs of the pivots are corroded, the arms may independently move further out of adjustment and possibly back in temporarily.

Actually, I couldn't find anything else that made sense and the motor wasn't too expensive, so I replaced it just hoping it would solve the problem.

I have removed the wiper arms. It was VERY difficult the first time, which makes me think they would not have moved easily on the shafts. I don't see a lot of corrosion on the ribs, and I'm sure the nuts are tight. I can't get them to slip on the shafts using manual force against the motor - at least not without applying more force than I am comfortable with, so I'm confident they aren't just flopping on the shafts.

If I stop the wipers at the top of the stroke, I can move the wipers manually all the way to the park position, but I can only move them a few inches back up before I get solid resistance - probably 6 inches at the tip of the wiper - about to the point that I would expect to be the bottom of the normal stroke. I don't find more than 1 inch of play in the wipers on my other vehicle (1999 Chev Suburban), but I don't know if this is normal for the Subaru.

This started after snow was allowed to pack up under the wipers during a snowstorm, and I could see that the amount of play could just about correspond to the amount of snow that was packed up, I just can't isolate the movement in the system.

The variation in the stroke distance is literally several inches - 3 or 4 inches at least - from what I would expect to be the normal and the greatest travel that I am seeing, and I see travel anywhere in that range.

If I were confident that the problem is with that 6 inches of play, I would just replace the transmission, but I really don't understand whether there is some other control on the amount of travel. As it stands, I see a normal stroke some of the time, but most of the time it seems to stop when it hits the windshield frame and the cowl cover at each end of the stroke, and it hits hard enough to bounce when it hits the cowl cover.

Please let me know if you have any further thoughts, but it seems to me the play has to be in the transmission.

Thanks

Tiny
Rlgates2
Dec 10, 2009.
Ahhhh..the snow build up...

Was that a reman motor you used? Sounds more like the motor knowing the pivots and arms are good.

IF you try to move the wipers and there is no movement, then the transmission is okay.


http://www.2carpros.com/forum/automotive_pictures/30961_wip_2.jpg



I do have a series of electrical test that may help if you want to go that route.

"If I stop the wipers at the top of the stroke, I can move the wipers manually all the way to the park position, but I can only move them a few inches back up before I get solid resistance - probably 6 inches at the tip of the wiper - about to the point that I would expect to be the bottom of the normal stroke. "

If you can see the wiper motor arm and see it moving while you do this and it is moving, then this is internal in the motor most likley.