2002 Impala 3.4L 189.6k: Passenger Wiper Arm Doesn't Move

2002 Impala 3.4L 189.6k: Passenger Wiper Arm Doesn't Move

Almost embarrassed to post this because I've done so many other much-more-involved repairs (LIM gaskets, Front Cover gaskets, etc.), but the wiper motor "post" is turning inside the arm, but the arm is not moving. Appears that the arm itself is stripped?? Surprisingly, there is no plastic cover over the nut, so I just removed the nut (13mm), but then I could not budge the damn wiper arm trying to get it off. So I sprayed it with PB Blaster a couple of weeks ago and haven't touched it since.

Is the only fix for this a brand new wiper arm? What's the deal here - is the metal on the motor post harder than the metal inside the wiper arm ... and it just ends up stripping the metal away in the arm hole? It is that soft "pot" metal on the wiper arm? I realize I'm at almost 190,000 miles, but I've never had a wiper arm fail on me like this. Some have rusted and requiring painting, but never metal failure like this.

And what's the trick to popping off the arm? I put a crowbar underneath and starting softly prying, but underneath was just the plastic, flexible cowling. Do I have to remove that, too, then use a block of wood underneath or something.

Talk about a PITA for such a trivial thing.

Lastly, anybody bought the Dorman knockoff? Does it look different from the OEM one? The GM OEM part is around $50 while the Dorman is less than half that, but if it's going to be obvious that it's not original or is just plain 'cheap', I'll get the genuine GM part.

Trivial or not, you need to have functioning wipers.

The wiper arm end is usually die cast zinc (or an alloy) while the post is steel. The arm should wear first, and it sounds as if that's what happened. New wiper arms are available in any number of places.

It is no surprise the shaft rusted and seized in the arm, and now is turning and galling into nice cylindrical grooved patterns holding the arm in place. Removing the old one may require small a two-jaw puller. Loosen the nut but keep it in place to prevent damage to the threads from the puller pilot.

Blue Bowtie:

I've been inspired to try to tighten it down more. Silly that this thought never occurred to me. I just saw that post spinning in the center and immediately assumed the splined teeth had stripped away. Now I'm thinking there ARE NO splined teeth - just a tight nut holding down on the arm.

But if re-tightening doesn't work, I may try looking for a special washer with biting teeth that I can put underneath the nut to try to get it to grab that way.

Just ridiculous to have to replace the entire arm because of this...

If you don't figure it out you can always go to a scrap yard for a good used part you need.

rhandwor,

True, but I'm increasingly finding junk yards that won't do anything for less than $20. And there are no pull-apart yards within 100 miles round trip of here, so that's not an option, either.

So it becomes a question: do I want to pay $17+shipping to Rock Auto for the Dorman knockoff, $48 for the GMPartsDirect genuine GM part (new), or some number in between for a junkyard GM part which might not last (since it's already been pressed onto another motor post).

I'm probably just buying the Dorman knockoff.

I found it interesting that none of the (3) GM dealers I called would discount the $75 mfg suggested list price (even though GMPartsDirect discounts $27)! I've bought several parts from the local Ford dealers over the years for my '97 Taurus and they give me the discount, no questions asked.

I've found Rock auto shipping is probably cheaper than gas for an hours drive.

The wiper drive shaft should have a slight taper. I presumed (probably incorrectly) that the nut was already tight. It may be possible to add some shim/washer and tighten it further onto the taper, or maybe not.

I wouldn't worry too much about installing a "knockoff" wiper arm. GM doesn't have a production facility set up to manufacture wiper arms and components - They buy them under contract from the same kinds of places which supply the aftermarket.

Well, just tightening it did the trick (it appears). Shop manual said "22 ft-lbs" of torque, so that's what I gave it. Turned the wipers on with a dry windshield and it moved normally. Also checked the driver's side and it took a couple quarter turns, too, to bring it up to torque. So I hope that's all it is. I didn't bother to add the special washer, but I'll be trying that later if it turns out it starts slipping again.

One thing I *did* notice - and it's only cosmetic, but the Shop Manual shows plastic caps atop these arm nuts. No caps on my Impala. Wonder if they fell off or someone took them off. I remember about 10 years ago driving this vehicle up to my parents house in MA and finding the black plastic tube inserts from my LeBra sitting in the wiper cowling area. Some wise guy had pulled them out and put them there as a joke so they'd go flying off the car as I drove along. I just happened to noticed them sitting in there (somehow). Maybe this person took the plastic caps on me. Anyway, I thought the exposed nuts looked odd because my Taurus has molded black plastic covers over it's arm nuts - giving a very finished look.

Thanks guys for saving me from needlessly buying a new arm

my driver side does this all the time. 1/2" nut needs to be tightened almost an imeasureable amount of turn and i'm back in business