95 850 wagon. Seems kinda strange, but when the windshield wipers are on, say in a steady rain, the drivers wiper will creep over and over (doesn't lift off the glass) untill after about 10 minutes, the wiper is way over to the left and off the end of the windshield. I only notice this on the drivers side. I don't think the arm is loose on the shaft- I can push it back down and it will work fine. For about 10 minutes. Like there is a loose belt in there or something.

Any idea on this? One of those pesky little problems that I always seem to forget- until a rainy evening... Dave

 

is the nut that holds the wiper arm on loose? thats what it sounds like to me... if that's not it, the splines that hold it in place are worn out.

 

If it stays in the wrong position after it's turned off and back on, I'd say that nut is loose.

 

Nut is tight. As far as I can tell, the aluminum arm is not slipping on the shaft. It doesn't seem to get any worse, no matter how many times as I push the arm back down.

If the arm was loose on the shaft, it would just stop moving eventually, right?

 

When you say "push the arm back down" are you referring to pushing it back to it's proper "parked" position at the base of the windshield ??

If so, next time you shut it off and need to push it down look at the nut (threaded stud) and watch to see if the nut (threaded stud) turns with the arm as you're pushing it down or if it's steady and the arm is rotating on it.

If it's rotating the arm might be stripped out and the nut is tight on the last bit of threads of the stud but not jammed against the arm itself and holding pressure against the studs serrations. If that is the case. Remove the nut and the arm from the stud. Use a wire brush, I use a battery brush or whatever to clean the aluminum shavings from the serrations in that tapered stud. Find a couple, 3, 4 washers that fit over the stud. You should replace the arm but you can tighten it up one more time using enough washers so that the nut doesn't bottom out. This way you have clean serrations biting into the aluminum wiper arm and the nut is pressing down on the washers pressing down on the arm holding it into those serrations.

Nothing else in that wiper transmission should be able to do what you're talking about but there is always a first time.

 

Well I just went out and looked her over. Nut is tight but yes as you all predicted, the arm turns but nut stays put. I thought if it slipped this bad it would just stop working altogether. I blame ice, snow and me hitting the wiper lever when the blades are stuck to the glass.

Looks like I've got the old "stripped splines" syndrome. If I could get a drill in there, I bet I could pin it. Ill try the washer trick. Wonder how much I'd need to replace if I wanted to buy some new parts to tackle this. Dave

 

No DRILL, no drill

All you would need is a new wiper arm. The stud or shaft with the serrations is steel and the arm is aluminum. The arm gives way to the stud. All you need to so is dig out the aluminum clogged in the serrations and either go with the washer trick or get a new arm. It's the same amount of work just don't need the washers with a new arm.

One thing I forgot to mention. Sometimes you need to drill out the very top of the arm for the washer trick. If it chews out enough aluminum in a cone shape from the arm sometimes it leaves a "lip" at the top where the nut goes. Sometimes you need to drill the lip off so the arm can slide further down on the serrations. You don't want to drill the whole thing bigger, just remove the lip if it had one.

 

Kiss- ok, I think I'll go the new arm route- kinda unusual for me, buying a new part and not fixing the old one, Guess I thought both parts were aluminum and the stud was worn. Sounds like an easy fix. Thanks! Dave