Wiper Linkage Adjustment (write-up on p 2)

[MadeInJapan]

Plenty of posts here on this forum about the non-contact of the driver's side wiper arm to the windshield.
My son's '94 850 had that issue but things are not what they seam...the arm got loose and with him using it anyway, the threads above the spline on the post that the arm fits over have worn some...that and the hole in the arm itself became enlarged. We dealt with it for some time with rags, tin foil, washers, you name it.

Anyway, the rainy weather has persisted around here and things finally came to a head to where I ordered a new arm from FCPGrotton. It came today and I spent some time before he went to work on trying to get the new arm on the splined shaft. Problem is that the hole in the arm seems way too small...I can't get it to make a good fit...I do try to hold it and put the bolt on the top and tighten it down but due to some of the threads being worn, at one point the bolt just turns and won't tighten. If I take the arm completely off, the bolt does tighten down on the post (without the arm). So, what to do? Any suggestions? I could take a hammer to the arm and hammer it on the splines hoping to get the arm snuggly on but there is a concern- awfully close to the windshield. I'm beginning to wonder if they sent the wrong arm (like I said, the hole seems way small)...but it is labeled for 850 and looks identical to the original arm (except the hole). I just can't get the arm on the post down far enough to give me the threads that allow the bolt to bite. Once again, any suggestions?

[JRL]

May be the wrong arm but I'm surprised that you Dave, would use the word "dreaded" of all people!

[erikv11]

I ran into something like this once before on an 850 driver's side. The soft metal of the arm hole had been worn away and wedged into the splines of the motor shaft. I went at it with a very stiff wire brush or little screwdriver, I don't remember actually, and was able to get the splines cleaner, deeper, and get the arm on.

[BEJinFbk]

It does sound like the splines may be full of crud.
Get in there with a sharp, pointed implement...
It may take a bit, but scrape out each one.

[MadeInJapan]

Thanks...and yeah, I know JRL- unlike me but I haven't done much to any of the cars lately except for typical maintenance.
I did use a wire brush to clean the splines but I'll go at it with a pick. Are there no splines at all on the arm side? I noticed none on the old one (figured they were worn away) but none on the new one either. Seems something is odd- or is the post suppose to dig into the softer metal of the arm hole and make it's own negative splines?

[matthew1]

Hi Dave!

As a last resort, you can use an impact wrench. It grabbed threads on my strut shaft that weren't grabable otherwise. Just be careful. Put your weight on it and blip the trigger.

[holler1]

MIJ,
Wanting to help, but not wanting to take my wiper arm off in the cold weather, I did a quick search. The suggestion below - from an old post on this forum - is a little drastic but might work as a last resort. It seems strange to me that the new arm would not have any splines at all. Also it sounds like the threads are worn out in one place if the bolt doesn't tighten down. Maybe add a washer to give better threads to work with? Someone else suggested using a helicoil to repair the threads.

Re: 850 wiper arm problems

New postby Paul-93-850 » Mon Dec 07, 2009 11:18 pm
After securely tightening the arm in place and testing the wiper, I drilled a 1/16 hole through the arm and post then put a 1/16 cotter pin in the hole.
Drill slow and keep oiling the drill. Use a fine wire brush and a little file to knock out the metal that accumulates in the drill bit channels.

Make sure you or someone can drill straight, you only get one clean shot.

[BEJinFbk]

I've never seen a brand new arm, but it wouldn't surprise me if the bore was smooth.
I've repaired many wiper arms that had been locked down by ice. The spline shaft is
always a much harder material than the arm. In more than one case, the arm was worn
smooth. The fix has always been to clean the splines out and reattach the arm. The
trick is not overtightening and breaking something. I'm not sure if I'd use an impact.
Maybe a few mellow taps with a nonmetallic, shot filled mallet.

The cross drill idea? I think the whole idea behind a new arm is NOT having to resort to cotter pins and such.
And it seems like adding a new failure point on something using that much torque is really asking for trouble.
If the splined shaft broke at that point, the whole thing would have to be replaced. What a PITA!

[MadeInJapan]

Well, after hours of frustration, I've come to the conclusion after trying several things including pounding on the arm from above (hood lifted all the way to make room) with a long socket extension to try to get the arm to seat lower, that the only reason that I was able to grab thread with the old wiper arm was because it was bored out so bad. If I ever get the new arm that far down, it too will not hold. So, the real problem is that the stud that is sticking up has lost ANY usable threads. This problem has nothing to do with dirty splines, etc. So, the question is, can new threads be made...maybe use a smaller nut to lock the arm down or do I have to replace the whole contraption? I'm going to look to see if there is a salvage 850 I can take the wiper motor out of after work tomorrow. In the meantime, I'm going to do some research on cutting new threads on the existing stud. Oh, and my son needs his car tomorrow and we're suppose to have storms here after lunch.

[MadeInJapan]

Okay, another idea- just cut new threads in the stripped stud and use a smaller nut to fasten the arm down- this would be much less hassle. Can anyone recommend such a die kit to do this with or a business that might be able to do this for me...I don't have much time, the rain is coming.

Other option is to buy a wiper transmission on eBay and take my chances, but it would be days before it gets here.
No salvaged 850's in town that I was able to find to take the part from.