Hi all,

wipers failed while my wife was driving in heavy rain today.

when i removed the wiper arm nut cover, I can see the spindle moving normally. And upon closer inspection of the arm itself, the hole where its supposed to fit the spindle is almost completely smooth. I gather that the way this works is that the spindle grooves are supposed to fit in the wiper arms and like a gear system. And i also noticed fine metal pieces around the area.

Should be a simple replacement of the wiper arm i gather? Just wanted to make sure before i go off and purchase a new wiper arm.

Thanks all!

 

Awesome find.

Common as they come on the XJ40 and the X300. There was a bulletin I remember a very long time ago, that mentioned the periodic checking of the tightness of that wiper arm nut, as the issue you now have will happen if it is allowed to come loose.

Sadly, age has these cars not going thru the dealer network/s anymore, and the dealer/s not doing what they should when one turns up.

A new arm, some anti-seize, and your good to go, and check that nuts tightness (without being silly, coz it will break) from time to time.

 

Might be overkill, but you might consider wrapping a little PTF (Plumbers white tape) around the spindle first, as it will help to take up any slack that might have arisen if there is any slight wear on the shaft also.

 

i have a different wiper problem.
It now doesn't return to the horizontal resting position, but sits up about 20 degrees.
This happened after I was cleaning the windscreen at the gas station, and the wiper was on intermittent but I didn't realise (switch got bumped)
As I was washing the screen, the wiper came up and hit the brush hard (my fault)

Now it sits up a bit. When the wiper first starts it moves right down to where it should rest, then changes direction. So it still has its full arc of movement, but rests up too high.
I have tried forcing it down a bit when turned off, which has improved it from about 40' above horizontal to 20'
I don't have the ***** to push further in case I break it..

 

I've not installed the wiper arm on the X300, but if like most others you need to loosen the nut and remove it, not push/force it as you'll strip the knurled "socket" in the arm.

There are two ways I've seen arms attached:

1) Keyed: The arm is keyed to the shaft, and can't slip without breaking the key or the arm. My Riviera has a keyed arm/shaft. The advantage is that there is no adjustment guesswork and a new arm is always perfectly aligned, and it is very strong and can "fight" things like snow..... to a point, until it can't and something breaks like the linkages under the cowl, which is no fun.

2) Knurled: This seems to be the most common. The shaft is knurled and usually slightly conical, and the arm is pressed onto the shaft with the mounting nut. This presses the arm's socket, which is usually a soft alloy, onto the knurles which bite into the arm socket. This is advantageous as you can find just the right spot and adjust the placement of the arm when installing (the keyed version solves this though), but the real advantage is that this alloy knurled solution is an engineered failure point designed to protect the wiper arm and linkages. If for example there is a very heavy ice/snow load and one turns on the wipers, the soft alloy socket in the arm will 'strip out' before anything else breaks. Or like your example if the arm gets stopped, again the socket will strip out first.

In the 'stripped out' scenario, you tend to get one or maybe two chances where you can reposition the arm and just re-tighten the nut and all is well. But after it has been stripped a few times, the socket gets wallowed out and the shaft won't grab anymore and a new arm is needed. Oh, and before you re-tighten the nut, it's a good idea to take the arm off and clean out the stripped alloy that is in the knurles.

In your case, I suspect you should take the arm off after verifying the wiper system is off and thinks it is stowed/down, clean off the stripped alloy from the shaft and any inside the arm socket. Then reinstall the arm where it should rest when off.

If the arm isn't fatally stripped out then you should be good. If it is too far gone, then you'll find out when it eventually starts 'flopping' and failing to stow as it creeps/slips on the shaft. If so, you'll need a new or good used arm.

I had this happen to our Roadmaster when my daughter tried to clear her windshield of heavy snow, stripped them right out! I tightened them up, but they eventually started flopping all about. Fortunately they were sold aftermarket for about $20 each!

Good luck!

.

 

the coupling is a splined taper.
Mine is not worn or loose.
It just doesn't sit in the 'home' position since it hit the windscreen brush. However it goes the full range when operating.