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2002 Rear Wiper Seized - How To Repair (w/pics)


BowTied
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Rear Wiper, 2002 Pathfinder


Symptoms/Assessment

Recently during the cold weather the rear wiper on our 2002 Pathfinder LE decided it wouldn’t move (reeeealllly slow) and couldn’t park anymore. I manually helped it park as it was still on and trying to park, sort of humming away, even though the truck was off. The 10A dash fuse was pulled to prevent battery drainage until I could repair it; the side effect on our truck was the power outlet inside the console was also on that circuit. :wtf:


In my case I was fairly sure the cause was that the years of snow salt and other contaminants had gotten into the shaft stem and was creating too much resistance to move in combination with the cold weather. The motor was humming and trying to make the wiper go but wasn't moving. This failure was fairly sudden as the wiper seemed to work in the warmer weather in the preceding week.


The following are the major steps I took to remove, disassemble, clean and re-grease, and reinstall. Not every step is outlined, I was taking pics for my own use and decided to wrote this later. I peg the difficulty of this job as reasonably low, though some experience with when to be rammy and when to be gentle is recommended. If you can do a wheel bearing or a stereo install this shouldn’t be too hard at all. If an oil change is your limit of experience, you might want some help.


Tools

Metric wrenches/sockets

Small flat blade screwdriver

Small Philips screwdriver

Soft face hammer

Aerosol-spray lithium grease

Trim removal tool for “Christmas Tree” plastic push clips

Emery cloth (or fine sandpaper/steel wool)

Small wire brush

Liquid Wrench or similar Penetrating Fluid


Optional but recommended

FSM

Anti-seize

Second set of hands

Patience

Beer


Thanks go to my friend Rob for his help and guidance. Rob had completed a similar repair on his 2001 SE but remarked that the wiper transmission was a different design. 2001 and earlier owners take note that this write may be wrong or incomplete in places for your needs. 2003-4 owners – let me know if there are differences in your model so that we can note it here for future reference.


First step is to remove the wiper blade and arm assembly. Using a small blade screw driver pop the cap off of the wiper arm pivot point and remove the nut. It may need some penetrating oil. You’ll need to firmly hold the wiper arm so that you aren’t applying torque to the wiper transmission. Second hands may be helpful

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The next step I found was the most difficult of the whole process, freeing the wiper arm from the shaft. Liberally soak it with you favourite penetrating oil. Using a soft face (I suggest a plastic face, though lead or brass may work) hammer so you don’t bugger the threads and whack the stud while working the arm around. This will let the penetrating fluid seep in. Some reapplication of fluid and more whacking may be needed. Some light tapping on the side of the wiper arm at the pivot may help. This is one those places where having the some experience will help you determine the need to tap the stud hard to free things up but not bludgeon the threads, dent the tailgate, dent the wiper arm. Be patient, this may take a while. If you get past this the hard part is over. If you don't have a soft face hammer get a buddy to hold/work the arm and use a pc of wood and regular hammer. Don't bugger those threads!


Once the arm is off, remove the rubber boot that weather seals the wiper shaft to the tailgate. It has an inner lip so squeezing it to pop the lip out and working it around may be needed. I realized after the fact that taking the boot off after removing the wiper assy may have been easier. If you have the time, check this spot for any rust forming and deal with it.


Remove the inner tailgate cover: There are two screws holding the grab handle (pop off small trim covers at each end of handle) and a series of those annoying plastic push clips around the perimeter of the panel. Note the panel covers the window latch (window needs to be open to access, see red rectangle). I started at the bottom of the panel with the push clips and worked my way around.

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Set the cover aside. On the inside you should see the wiper assembly and its mounting bracket has 3 bolts that go through rubber isolation washers (green circles, one was cut off in the pic). Remove the 3 bolts and don’t forget about the harness – the harness has a push tab on the side to disconnect the wiper motor. I needed a small flat blade to push on the connector tab (extra hands may be helpful here). The bracket needs to be slid to one side to get it out, not hard.


Assembly Out

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Other side

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(continued...)

Edited by BowTied
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Once on the bench you see three more bolts hold the wiper assembly to its bracket. Take note of the orientation of the wiper to the bracket and the bracket to the tailgate then remove the wiper from the bracket.


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The intent is to get the shaft out of the assembly so that the shaft and the shaft housing can be cleaned and re-lubed. This requires almost complete disassembly. First, the wiper arm end of the shaft has a retaining clip, washer and an o-ring. You may need to remove dirt and grime with a wire brush to see the C-clip opening on the shaft. The clip is flat on one side of the opening and bevelled on the other (pic below). Using a small flat blade on the tapered side you can work it out of the groove and around to remove it. This is tedious, requires patience. The clip is easily deformed, go slow and easy. I bent mine a little and squeezed it back into shape in the vice before reassembly.


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Under the clip is a washer and an o-ring. Only remove the o-ring now if it presents as easy to do – you don’t want to rip or tear it with sharp tools. It may come easier in later steps if not now.

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Flip the assembly over. To remove the plastic cover that protects the circuit board (handle with care) there are little lock tabs that need to be lifted. Only lift them the smallest amount as they are fragile, I broke one lifting it too much with a medium sized flat blade; they seemed quite fragile. You might find a second set of hands useful here and possibly some tooth picks or similar to keep the one side of the cover ajar while working on the other side.


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Remove the circuit board mounting screws (I think there were two). The circuit board has a pair of spade connectors soldered in place on the underside that connect to the motor. Gently wiggling the board as straight up as possible will remove the circuit board. Be careful not to stress the solder connections on the board!


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This pic shows the board removed and flipped over to reveal the connectors. They are similar in design to crimp on spade connectors.


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(continued)

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Set the board aside in a clean dry spot that protects the electronics. The plastic cover under the board comes off with 3 screws to expose the worm gear assembly. Note on these screws - this plastic cover is soft and over tightening these screws will deform the plastic cover. Side note: worm gears are great in that they can transmit a decent amount of torque and cannot be back driven – so unless the motor is trying to turn you cannot seat the wiper arm by pushing on it. Since the gear assembly cannot be driven backward you will only bend or break something.

The driven gear is attached to the long shaft and should be free to be removed if the C clip is off. Don’t forget about the o-ring if not removed in previous step – the o-ring may cause resistance to removal, be gentle.


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What should be noticeable at this point is that some of the white lithium grease is dried and the places the shaft rotates (on the shaft itself and within the housing) are crudded up with dirt and/or corrosion. Use a small strip of emery cloth and clean up all those surfaces. 0000 steel wool, very fine sand paper or similar may work. You want to remove the crud to reveal shiny metal without scoring the shaft or housing surfaces. Also make sure the area where the o-ring, C clip, and the shaft threads are get cleaned up very well, a small, fine wire brush may help with the clip groove and threads.


Note the following pic of the gear – there are slots in the gear and the bars between the slots interact with a tiny limit switch on the circuit board (above pic of board, tiny black button with little blue rubber boot - this aligned with the rectangular hole in the plastic cover). This is what tells the motor to when to change directions or where to park. This area should NOT need to be greased. FWIW the tiny limit switch when gently depressed has an audible click – thought that might helpful in trouble shooting for someone.


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Using lithium spray grease (I do not recommend any other grease, especially in cold climates – it will be too thick and heavy when cold and will strain the motor/cause slow or no movement) coat the gear teeth and the shaft. Spray some grease in the housing where the shaft goes as well. Spray some grease on the driving gear and the housing area where the gears mesh. Avoid grease near the motor/connections and slide the gear into the housing. Slide the gear/shaft back into the housing. **The largest slot in the gear must be facing the limit switch.** You can eyeball this by looking at the plastic gear cover and noting the hole for the limit switch. Doesn't need to be perfectly aligned, so long as the largest of the slots is over the limit switch - calibration will be done after assembly.


Remaining assembly is mostly reverse of removal. Don’t forget about the o-ring which I greased as well to help it stay in place and seat and seal well. Clean the lip of the weather boot before install. I greased this lip too to help it seal and slow corrosion.


Do not install the wiper arm yet! If you do without the following steps the wiper may not park all the way down or worse, may try to park much lower than the hard stop allows. Get everything together and without the wiper arm on, re-install the fuse and cycle the wiper verifying the delay and park features are happening by watching the shaft rotate. The window and hatch may need to be closed for it to work. Assuming it cycles as intended, power down and then you can install the wiper arm in the park position. Torque per FSM and be sure to hold the wiper arm so you are not torquing the wiper transmission. Before installing the arm, grease the wiper arm pivot point, the spring, and apply anti-seize or grease to the shaft where the arm mounts. I also liberally greased the weather boot (don't forget to put it on!). Test it carefully (wet the window to reduce friction) after install and then double check your shaft nut torque. I also put some grease on top of the nut before putting the plastic cap on to mitigate corrosion.



I hope someone finds this useful. Open to questions or comments.

Edited by BowTied
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Thank you so much, this will definitely be one of my next projects. As the current motor skips, and doesn't park either, even in warm conditions.

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