Rear Wiper Arm Shaft Fix

[ScooterMD]

What a horrible title!

Thought I'd post a brief write-up on overcoming a pesky non-functional rear wiper...

This is an 07 Sport from Ohio that is blessed with thick coat of midwestern rust. When I bought the truck last year, the rear wiper did not work (see note about dealer from whom bought this truck below). After pulling off the cover at the base of the wiper arm, I found that the nut that holds the arm onto the wiper motor was horribly rusted. After heat and grease to remove the nut, I found the aluminum within the base of the wiper arm was horribly corroded, so much so that the arm basically just spun freely on the tapered spindle on the motor shaft. So I bought a new wiper arm and thought I'd be set.

Unfortunately, the threaded end of the motor shaft was also horribly corroded, so much so that there wasn't enough thread remaining to replace the nut that holds on wiper arm. I tried to re-thread the end of the shaft, but to no avail. See attached pics of corroded threads from above (1) and below (2).

I also tried shaving down the threads and then re-threading with a smaller die, but that didn't work as well.

So I used an angle grinder to cut off the threaded end of the shaft, see pic 3. I cut it off flush with the tapered spindle.

I then drilled out about 1 cm into the motor shaft with a 1/8" bit and threaded the hole with an M4x0.7 tap. See pic 4. I marked the threads marked with an arrow.

Unfortunately, I forgot to take a picture after drilling out and threading the hole, so I only have the pic after installing the wiper arm. Note that once you install the wiper arm in firmly, the tapered spindle will dig into the aluminum on the wiper arm, so I didn't want to remove the wiper after attaching it.

I then used used an M4x0.7 bolt to hold down the wiper arm; see pic 5. I had to add a bunch of washers to account for the limited depth of the threaded hole I made in the shaft.

It's worked so far; we'll see if it holds. Has anyone else done a similar fix?

Note that the alternative is replacing the motor. This requires removing the rear door panel. The parts for this are Toyota OEM 85130-35080 for about 170 or 8513035080 for a Cardone replacement for about 90.

*** Note: beware of Honda of Mentor. I bought the 4Runner from them online; it was unbelievable how much was wrong with the it. Total crooks.

 

[AuSeeker]

Nice repair, I hope you used a little Loc-tite to help keep the bolt from loosening.

I haven't seen anyone else do this to repair on a corroded shaft, even though I made the suggestion to cut and tap the shaft to those that have had the same issue as you had, they always said the shaft wan't big enough for this to work, everyone ended up replacing the motor to solve the issue, good seeing someone proving them wrong, I hope it holds up for you!!

 

[46runner]

Creative! Similar problem here. I replaced my wiper motor with a used one.

 

[ScooterMD]

Creative! Similar problem here. I replaced my wiper motor with a used one.

thanks. where did you find a used one and do you remember how much it cost? and did you need to replace the wiper arm at the same time?

 

[46runner]

thanks. where did you find a used one and do you remember how much it cost? and did you need to replace the wiper arm at the same time?

Around $40 from someone parting out. I replaced the wiper arm too. But you shouldn't have too if it's in good shape.

 

[jasonw3]

thanks. where did you find a used one and do you remember how much it cost? and did you need to replace the wiper arm at the same time?

I took one off a 4runner at a salvage yard. About $25. After reading this thread, I'm thinking about trying this fix before I spend an hour and take apart my liftgate to swap the wiper motor.

 

[ScooterMD]

I took one off a 4runner at a salvage yard. About $25. After reading this thread, I'm thinking about trying this fix before I spend an hour and take apart my liftgate to swap the wiper motor.

highly recommend. it's been well over a year and the rear wiper is still working great. as long as you have a tap and die set, a drill & titanium bits, and an angle grinder you should be fine; 30 min max. and if you f it up, you can then swap out the motor.