yargnits
Full Access Member
- Joined
- Jan 27, 2010
- Posts
- 236
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- 36
I had some time to do something mechanical again (yay!). Last year my rear wiper started working very slowly and eventually stopped. I assumed the motor was weakening and going out. I put off replacing it until this coming winter was upon us and had a bit of sticker shock when seeing the prices of a new motor.
So, I turned to the internet community for a cheap self-fix solution and was convinced that the problem was a bad ground wire. I tested tested the connections and everything seemed fine. Still thinking my problem was a ground I ran test jumpers everywhere to see if that solved the problem. I even took a wire all the way back to the battery ground with no effect.
Side note here - The reason I was convinced that the issue was a bad ground was because I stopped getting rear gate and window open warnings on my dash. Since those function by grounding a connection it seemed to fit. Well, my test light and Fluke meter were not lying to me, the ground was fine.
What the eventual problem was (for me) was a seized bushing in the unit itself. I'll try my best to describe how the fix went below.
Please refer to the photos as mentioned in the the text.
Photo 1 - With the motor on the bench I removed the cover by releasing the 2 clips pointed out with the red arrows.
Photo 2 - With the cover off the circuit board is visible. I checked for darkened areas of the board which would indicate component failure on the board itself. Since there were none I proceeded to look for problems elsewhere. The circuit board is held in place with small clips and all connections are via posts that come from underneath then through the board. Gently release the clips while pulling the circuit board straight up, sliding off the posts.
Photo 3 - I used a solder sucker to quickly heat the solder and free the motor connection tabs indicated by the green arrow. Be careful not to heat these up for too long or you'll melt the plastic under them and possibly something inside the motor. Once they are free gently bend them up at a slight angle and remove the 3 screws indicated with the red arrows.
Photo 4 - After removing the plastic plate you will see a worm gear configuration (see photo 8). I used a Sharpie to mark the gear position - the gold plate shown on the gear is used for sensing wiper position back to the circuit board. At this point I *tried* to pull the gear directly out but it didn't budge. I examined the outer casing to see if there was a retaining clip but found nothing. I didn't want to pry on the gear in fear of damaging it so I made sure the wiper arm retaining nut was on (to protect the threads, you newbies) and tapped it gently with a hammer, then harder, then harder... I eventually clamped the housing in a vise and kept taping harder until the shaft started backing out of the casing. During this time I tried turning the shaft/gear once it had cleared the motor gear. It took quite a bit of effort to turn. This is when I realized I found my problem.
Photo 5 - after much persuasion I managed to get the shaft and gear all the way out. The bushing indicated with the green arrow (I'll call this the front bushing) spun freely easily slid up and down the shaft as I tipped it. The bushing pointed out by the red arrow (the rear bushing) was not moving. I'll note here that the O.D. of the front bushing is slightly larger than that of the rear bushing.
Most of my time for this repair was spent trying to free the rear bushing from the shaft. I soaked it in WD-40 for a couple hours with no luck. If/when you get to this point, remember you don't want to put a pair of plyers on the thing and chew it up or it won't go back into the housing. Mine was so locked onto the shaft I began thinking it wasn't suppose to move and kept re-inserting it into the housing to see it would spin better.
Photo 6 - This is where there seemed to be the most amount of resistance to the shaft being put back in so I put the shaft back in the housing while spinning hoping to free it up. Eventually I used a heat gun and a glass of water to heat the bushing. Keeping the shaft in cool water helped keep the shaft from overheating which could cause damage to the plastic gear. I did this a few times, taking it out trying to insert it into the housing.
Finally I decided to insert the shaft all the way inside and see when it felt like. Again, I was starting to think this bushing was not meant to come off. I used a center punch to gently tap the shaft/gear back into the housing and just about all the way in it popped through without much effort. I was able to lift the shaft/gear enough to clear the motor gear and it turned much easier, though it still felt rough. So I pulled the shaft/gear back out of the housing and...
Photo 7 - both bushings stayed in the housing. The rear bushing was deep in the housing and the front bushing is pointed out by the green arrow. The read arrow shows where a "bunch of crusty gunk" was on the shaft. Using WD-40 and shop towels I cleaned it up smooth again. I also cleaned the inside of the rear bushing by accessing it through the stem of the housing. I kept cleaning these areas until a clean shop towel would come back out/off clean. I tested the function between the shaft and rear bushing several times by putting the shaft in from the other side and eventually there was no resistance to spinning.
Photo 8 - I used axle grease when sliding the shaft back in the housing for the final time, coating both bushings. I then re-distributed the clear and brown grease for the electrical contacts and worm gear respectfully.
I bent the motor connection tabs back down so they would make good contact with the mating surface when the plastic cover was placed back on the housing. Replaced the 3 screws and re-soldered the motor contacts from photo 3. I slid the circuit board back onto the posts making sure the clips were holding it in place. I then put the plastic cover back on.
Lastly, I re-mounted the motor, plugged it in and it tested tested fine. I put the wiper arm back on and sure enough all is good in the world of rear-view winter driving again! I hope this helps someone out.
So, I turned to the internet community for a cheap self-fix solution and was convinced that the problem was a bad ground wire. I tested tested the connections and everything seemed fine. Still thinking my problem was a ground I ran test jumpers everywhere to see if that solved the problem. I even took a wire all the way back to the battery ground with no effect.
Side note here - The reason I was convinced that the issue was a bad ground was because I stopped getting rear gate and window open warnings on my dash. Since those function by grounding a connection it seemed to fit. Well, my test light and Fluke meter were not lying to me, the ground was fine.
What the eventual problem was (for me) was a seized bushing in the unit itself. I'll try my best to describe how the fix went below.
Please refer to the photos as mentioned in the the text.
Photo 1 - With the motor on the bench I removed the cover by releasing the 2 clips pointed out with the red arrows.
Photo 2 - With the cover off the circuit board is visible. I checked for darkened areas of the board which would indicate component failure on the board itself. Since there were none I proceeded to look for problems elsewhere. The circuit board is held in place with small clips and all connections are via posts that come from underneath then through the board. Gently release the clips while pulling the circuit board straight up, sliding off the posts.
Photo 3 - I used a solder sucker to quickly heat the solder and free the motor connection tabs indicated by the green arrow. Be careful not to heat these up for too long or you'll melt the plastic under them and possibly something inside the motor. Once they are free gently bend them up at a slight angle and remove the 3 screws indicated with the red arrows.
Photo 4 - After removing the plastic plate you will see a worm gear configuration (see photo 8). I used a Sharpie to mark the gear position - the gold plate shown on the gear is used for sensing wiper position back to the circuit board. At this point I *tried* to pull the gear directly out but it didn't budge. I examined the outer casing to see if there was a retaining clip but found nothing. I didn't want to pry on the gear in fear of damaging it so I made sure the wiper arm retaining nut was on (to protect the threads, you newbies) and tapped it gently with a hammer, then harder, then harder... I eventually clamped the housing in a vise and kept taping harder until the shaft started backing out of the casing. During this time I tried turning the shaft/gear once it had cleared the motor gear. It took quite a bit of effort to turn. This is when I realized I found my problem.
Photo 5 - after much persuasion I managed to get the shaft and gear all the way out. The bushing indicated with the green arrow (I'll call this the front bushing) spun freely easily slid up and down the shaft as I tipped it. The bushing pointed out by the red arrow (the rear bushing) was not moving. I'll note here that the O.D. of the front bushing is slightly larger than that of the rear bushing.
Most of my time for this repair was spent trying to free the rear bushing from the shaft. I soaked it in WD-40 for a couple hours with no luck. If/when you get to this point, remember you don't want to put a pair of plyers on the thing and chew it up or it won't go back into the housing. Mine was so locked onto the shaft I began thinking it wasn't suppose to move and kept re-inserting it into the housing to see it would spin better.
Photo 6 - This is where there seemed to be the most amount of resistance to the shaft being put back in so I put the shaft back in the housing while spinning hoping to free it up. Eventually I used a heat gun and a glass of water to heat the bushing. Keeping the shaft in cool water helped keep the shaft from overheating which could cause damage to the plastic gear. I did this a few times, taking it out trying to insert it into the housing.
Finally I decided to insert the shaft all the way inside and see when it felt like. Again, I was starting to think this bushing was not meant to come off. I used a center punch to gently tap the shaft/gear back into the housing and just about all the way in it popped through without much effort. I was able to lift the shaft/gear enough to clear the motor gear and it turned much easier, though it still felt rough. So I pulled the shaft/gear back out of the housing and...
Photo 7 - both bushings stayed in the housing. The rear bushing was deep in the housing and the front bushing is pointed out by the green arrow. The read arrow shows where a "bunch of crusty gunk" was on the shaft. Using WD-40 and shop towels I cleaned it up smooth again. I also cleaned the inside of the rear bushing by accessing it through the stem of the housing. I kept cleaning these areas until a clean shop towel would come back out/off clean. I tested the function between the shaft and rear bushing several times by putting the shaft in from the other side and eventually there was no resistance to spinning.
Photo 8 - I used axle grease when sliding the shaft back in the housing for the final time, coating both bushings. I then re-distributed the clear and brown grease for the electrical contacts and worm gear respectfully.
I bent the motor connection tabs back down so they would make good contact with the mating surface when the plastic cover was placed back on the housing. Replaced the 3 screws and re-soldered the motor contacts from photo 3. I slid the circuit board back onto the posts making sure the clips were holding it in place. I then put the plastic cover back on.
Lastly, I re-mounted the motor, plugged it in and it tested tested fine. I put the wiper arm back on and sure enough all is good in the world of rear-view winter driving again! I hope this helps someone out.
