REMOVING THE WINDSHIELD COWL AND FIXING NOISY / SQUEAKY WIPERS ON A MKIV CAR
The following procedure describes how to (1) remove the plastic cowl that sits at the bottom front of the windshield and (2) remove the wiper motor and mechanism for replacement or regreasing. The removal of the windshield cowl is not only necessary to access the wiper motor/mechanism, but it also allows for removal of the ECU. The wiper mechanisms of older MKIV cars tend to become very noisy (squeaky) and eventually sieze due to insufficient lubrication of the brass bushings for the mechanism linkages. If done soon after wiper squeakings starts, removing and disassembling the mechanism and regreasing the bushings will eliminate the squeaking and provide years of additional trouble-free operation. If the mechanism has seized and the motor possibly burned out, then these parts can be easily replaced with the assembly out of the car.
The procedure below is based on a '99.5 Jetta GLS VR6, but should be applicable to all MKIV cars and similar on other VWs. The time required to complete the procedure is approximately 1-2 hours.
The tools required to perform the procedure are:
- T25 Torx or Phillips screwdriver (to remove the pollen filter cover in the windshield cowl)
- small screwdriver (to remove the plastic caps that cover the wiper arm nuts)
- 10mm and 13mm sockets and wrench
- Scratch awl (or something similar) or a fine permanent marker for marking the motor shaft position relative to the mechanism linkage (helps ensure that the motor and linkage are reconnected correctly and the wipers are at the correct position at rest)
- tools to remove the external circlip from the wiper arm (I used two screwdrivers to push the circlip off and needle-nose pliers to pop the circlip back on)
If you are only removing the windshield cowl and not removing the wiper mechanism, perform steps 1 through 8 and 42 through 51. If you are removing and regreasing the wiper mechanism, perform all of the steps. Step 18 is only required if you are replacing the wiper motor, but is still recommended for regreasing the wiper mechanism since it removes some bulk, provides extra clearance for the mechanism disassembly and only requires that three 10mm bolts be removed.
PART I - REMOVAL and DISASSEMBLY
1. Raise the hood.
2. Remove the plastic cap (red arrow in picture below) from the pivot end of each wiper arm. The cap covers the nut that secures the wiper arm to the drive shaft. To remove the cap, insert a small screwdriver into the notch indicated by the yellow arrow in the picture below and twist gently to raise the cap. You may need to move the screwdriver to under other areas of the cap and twist again to get the cap to come off. It's on the nut fairly tight.
3. Remove the 13mm nut (red arrow in picture below) that secures each wiper arm to its drive shaft.
4. Remove each wiper arm from its drive shaft. The threaded end of the drive shaft is tapered and splined, so disconnecting the arm from the shaft is easier said than done. I've heard of a number of ways of doing it, but the way that worked best for me was to grab the arm at the place indicated by the red arrow in the picture below and wiggling the arm up and down (away from and towards the windshield) until it is loose enough on the splined shaft to be pulled off. It may take a dozen or so wiggles for this to happen. If it doesn't move easily, then pull/push harder.
5. Remove the pollen filter access cover from the windshield cowl by following steps 1 through 4 of the following DIY - Pollen Filter Replacement DIY. In step 3 of that DIY when told to pull up on the rear hood seal, go ahead and remove the seal completely.
6. Starting at one end of the windshield cowl (red arrow in the picture below), pull the end of the cowl straight out from the windshield (perpendicular to it) and work your fingers under it and toward the center of the car. There is a tab that runs most of the width of the cowl that snaps into a channel in a clip that is attached to the bottom of the windshield. You need to pull up on the cowl until you get the end of the tab to pop out of the channel. Once you get the end of the cowl to pop up, continue doing the same across the whole width of the cowl/windshield. Move the cowl out of the way when it's fully disconnected. For reference, the yellow arrow in the picture below shows the driver's side wiper drive shaft sticking through an opening in the cowl.
7. The picture below shows the clip attached to the bottom of the windshield. The red arrow points to the channel that the cowl tab attaches to.
8. The picture below shows the bottom of the driver's side end of the windshield cowl. The red arrow points to the tab that snaps into the windshield clip channel.
9. With the cowl removed, the wiper mechanism is visible. The red arrow in the picture below points to the motor drive shaft. The yellow arrows point to the wiper arm drive shafts.
10. Remove the rubber piece (red arrow in the picture below) that surrounds each wiper arm drive shaft.
11. Remove the three 10mm bolts indicated by the red arrows in the picture below.
12. Partially remove the wiper mechanism from its cavity under the windshield and disconnect the motor wiring harness indicated by the red arrow in the picture below.
13. Remove the wiper mechanism from its cavity under the windshield.
14. The picture below shows the orientation of the mechanism linkages when the wipers are at the rest (off) position. Note that the passenger's side wiper linkage (red arrow), driver's side wiper linkage (yellow arrow) and motor drive arm (blue arrow) are all aligned from left to right along the green line (the motor drive arm is oriented to the passenger's side underneath the driver's side wiper linkage). When reassembling the motor and linkage arms later in this DIY, it is critical that the linkages are oriented this way when the motor is at its rest position.
15. Move the linkage assembly so that the motor drive arm rotates approximately 90 degrees (1/4 of a turn), as shown in the picture below. This gives access to the nut that secures the motor drive arm (blue arrow) to the motor drive shaft. The red and yellow arrows point to the passenger's side and driver's side wiper linkages, respectively.
16. Make a mark on the motor drive arm and a corresponding mark on one half of the motor drive shaft similar to those shown in the picture below. These marks are used during reassembly so that the rest position of the motor corresponds with the rest orientation of the motor drive arm and wiper linkages. I recommend making permanent marks with a scratch awl or something similar. You can also use a fine permanent marker. Just make sure not to accidentally erase the marks during later steps of the DIY. Realigning the motor and linkage assembly is much harder to do without the marks. DO NOT FORGET TO DO THIS STEP!!!
17. Remove the 13mm nut indicated by the yellow arrow in the picture above. The linkage will likely try and move when you attempt this, so hold onto the linkages very tightly to keep them from moving and apply a blunt turning force to the nut (i.e., hit the wrench with a hand or hammer) to break it free without the linkages moving much.
18. Remove the 10mm nuts indicated by the red arrrows in the picture below. This disconnects the motor from the linkage assembly. This is not absolutely necessary to perform the rest of the DIY, but is recommended. It takes only a few seconds and makes the rest of the DIY easier. If you're replacing the motor, then this step IS required.
19. The picture below shows the driver's side wiper arm drive shaft. The passenger's side wiper arm drive shaft is identical in design, just oriented differently. If your wipers squeak, then most likely one or both of these drive shafts is no longer sufficiently lubricated. Diassembly and regreasing of the drive shaft(s) is usually sufficient to eliminate the squeaking. If squeaking has been going on for a long time, or the mechanism has seized, then the linkage assembly may be damaged beyond repair and would need to be replaced.
20. The drive shaft is secured in its housing by an external circlip, indicated by the red arrow in the picture above. Carefully push this circlip out of its groove in the drive shaft. I laid the drive shaft housing on its side and used two screwdivers to push the circlip off.
21. Remove the thick washer that sits below the circlip. The washer is indicated by the red arrow in the picture below.
22. The red arrow in the picture below points to an O-ring that sits below the thick washer. During insertion of the drive shaft into its housing following regreasing, this O-ring may pop out of its groove in the housing and ride up the drive shaft a bit. There is no need to do anything with it at this point.
23. Repeat steps 20 through 22 for the other drive shaft.
24. Slide the drive shafts out their housings.
25. The picture below shows two thin washers that sit at the bottom of the drive shaft. The lower washer is bowed. The upper washer is flat. Be very careful not to lose these! If there aren't two washers on each drive shaft, then check the bottom of the shaft housing to see if one or both is stuck to it.
26. The picture below shows the inside of a drive shaft housing. The housing has an upper (red arrow) and lower brass bushing with a cavity with slightly larger diameter in between them.
27. Apply some good quality grease to the bushing surfaces and add a little extra to the cavity in between them. You can't apply too much. When you insert the drive shaft back into the housing, the shaft will push the excess grease out.
PART II - REASSEMBLY and INSTALLATION
28. Make sure that the two thin washers are located on the bottom of the drive shaft. The bowed washer goes on first. The flat washer goes on second.
29. Insert the drive shaft back into the regreased housing and rotate the shaft a little bit to spread out the grease inside evenly. Wipe off excess grease from the portion of the shaft that sticks out of the top of the housing.
30. If the O-ring has ridden up the drive shaft, carefully push it back down into its groove in the housing.
31. Put the thick washer on the drive shaft.
32. Push the drive shaft fully into the housing (to compress the thin, bowed washer) and reinsert the external circlip into its groove. I fit the tips of the circlip into the groove and then used needle-nose pliers to push the circlip onto the shaft and into the shaft groove the rest of the way.
33. Repeats steps 28 through 32 for the other drive shaft.
34. Reconnect the motor to the linkage mechanism using the three 10mm bolts.
35. Reconnect the motor drive arm to the motor drive shaft by pressing the arm onto the splined shaft. Make sure that the marks on the arm and shaft are lined up. Tighten the 13mm nut onto the motor drive shaft, making sure that the drive arm does not rotate relative to the drive shaft. If it does, remove the drive arm from the drive shaft, realign the marks and try again. If you didn't mark the drive shaft and drive arm, or if the marks are no longer visible, see the TIP at the end of the DIY.
36. Insert the reassembled motor and linkage assembly into the cavity below the windsheild.
37. Reconnect the motor wiring harness to the motor.
38. Reconnect the motor/linkage assembly to the car using the three 10mm bolts.
39. Turn the car ignition on and operate the wipers for at least one cycle. This will return the linkage assembly and wiper arm drive shafts to the correct rest position.
40. Turn the wipers and car ignition off.
41. Reinstall the rubber piece on each of the wiper arm drive shafts.
42. Reinstall the plastic windshield cowl, making sure that the holes in the cowl are centered around the wiper arm drive shafts and the tab on the bottom of the cowl snaps into the channel in the clip attached to the bottom of the windshield glass.
43. Reinstall the pollen filter cover by following steps 13 and 14 in the following DIY - Pollen Filter Replacement DIY.
44. Reinstall the rear hood seal.
45. Reattach the wiper arms to the wiper arm drive shafts by pressing the arm down onto the splined drive shaft. Try to position each wiper arm on its drive shaft so that the closest of the two ends of the rubber wiper blade is approximately 1/2" or so from the upper edge of the windshield cowl.
46. Tighten the 13mm nut onto each of the wiper arm drive shafts. This will fully seat the wiper arm onto the splined drive shaft.
47. Wet the windshield a little.
48. Turn the car ignition on and operate the wipers for at least one cycle. Check to see that the driver's side wiper rubber does not travel past the vertical edge of the windshield glass, and that the tips of the both wiper rubbers are not too close to (or on top of) the windshield cowl when the wipers come to rest.
49. Turn the wipers and car ignition off.
50. If the position of the wipers if off, repeat steps 3, 4 and 45 through 49 as many times as necessary to get the position of the wipers correct.
51. Reinstall the plastic caps on the 13mm nuts on the wiper arm drive shafts.
That's it. Enjoy your quiet wipers.
If the relative positions of the motor drive shaft and drive arm were not marked in step 16, or if the marks are no longer visible, reconnect the motor wiring harness to the motor and have someone operate the wipers at least one cycle while you hold the motor securely. This will return the motor drive shaft to the rest position. Next, reconnect the motor to the linkage assembly using the three 10mm bolts. Make a mark on the end of the motor drive shaft that would line up with the motor drive arm when its in the position shown in the picture for step 14. The mark should basically be at the 9 o'clock position. Finally, make the mark on the motor drive arm that you should have made in step 16. You should now be ready to proceed with step 35.
As always, do this procedure at your own risk. I am not responsible for any mistakes in the procedure or those that you make while performing it.
Modified by VgRt6 at 12:49 PM 7-29-2009