After going through a car wash I noticed my rear wiper was pointed down, it was on the painted part of the rear gate.

When I grab it I can rotate it freely, I could feel no centering lock to put it where it should be.

I put it where it should be but after I use it, it seems to creep to where its wiping the tailgate and not the window.

Is there an adjustment?

 

I think your best bet is to remove the interior mouldings re the upper hatch and look at what is visible re the wiper motor.

Fortunately I have not had to learn about the rear wiper yet - well I did learn how to change the blade and I considered that a big deal - well a fuss anyway.

Wipers are just plain complicated both electrically and mechanically. Somehow I doubt that you see any obvious problem - and that is the problem but you have to start somewhere.

 

Well that car wash can pay for it. I'll put those "we can destroy your car and its not our fault" signs to the test.

 

I regard my 3 as too delicate for a car wash, afraid so to speak. Among other concerns, I worry that I might forget about the rain sensing wipers like one poor sod did.

The front wipers activated just as that big roller brush hit the windscreen. The brush grabbed one of the wiper arms off the windscreen and then beat it repeatedly down the glass roof. The pounding took out both the sliding and the fixed sun roofs. Unfortunately there was no glass insurance and hence what with the water damage to the interior and contents from the 3 continuing thru the car wash, the 3 was pretty much a write off. There was also something about the air bags as one had to leave the engine idling with the tranny in neutral so the circuits were alive.

The car wash operator of course sued for repair costs to his equipment and the subsequent downtime for the repairs. There was also the claim for the damage to the vehicle following as well.

The position of the car wash operators insurance company was that the owner of the 3 was negligent with regards to the operation of the rain sensing wipers. Since the owner of the 3 had no glass insurance, his insurance company declined to become involved.

Anyway, I assume that all your wiper parts are still on your 3 and that there was no damage to the car wash. One might want to read the fine print on the car wash ticket - there is probably something about liability and protecting the car wash from claims.

As I said, I am afraid of these mechanical automated car washes. I use a wand wash where at least I have some control.

 

Well my story is not quite as elaborate as the one you just told.

No rain sensing issues, no issues except the rear wiper. For all I know one of the men grabbed it when they did the wipe down. Its just loose now. If I grab it it will spin freely and wants to be on the black metal portion of the tailgate now.

The best washes are the touchless types, nothing touches the car.

Too delicate for a car wash? You have to be joking. Its a landrover not a yugo.

 

Something might be stripped inside now.

The LR engineers anticipated the blade being frozen to the glass and added one of those current sensing FETs to the circuit. If the wiper is frozen in place, the power circuit opens for a few seconds and then make two or three more attempts and then shuts down for few minutes and then tries again.

In other words, they did not plan on gorillas using the wiper as a lifting arm, a concern a mechanical slip clutch might have resolved. Maybe too sophisticated rather than delicate may have been a more appropriate description.

 

I fixed it. It was easy. It does have a sort of slip clutch to it.

The rear wiper was below the glass and I could move it freely with my hand. If I put it where it should be it gravity would just drop it down 30 degrees or so.

The fix was to remove that black cap and then put a socket on the bolt. I put the wiper where I thought it should go and gave it a 1/8 turn.

Seemed to fix it. I don't think there are any splines holding it. It seems to be just a friction fit. Which I guess is good, it will give way if something torques on it.

I could grab it now and still move it to a new position. I think the large nut probably loosens over time.

No need to tear the car apart to fix.

 

The rear wiper and washers operation is controlled by the CJB, via the rear wiper relay, which is located in the LH rear 'D'
post.
The rear wiper motor is located in the upper tail gate, behind a trim panel. The assembly is secured to the body of the
upper tail gate with three M6 nuts. Bushes isolate the motor assembly from the body, which help reduce the transmission
of motor operating noise to the tail gate.
The motor is located on a worm drive gearbox mechanism, which converts the rotary motion of the motor output spindle
into the required arc for the rear wiper blade.
The feed hose, for the separate rear washer jet, is located at the rear of the motor spindle. The hose is connected to a 90
degrees connector allowing the washer fluid to flow through the centre of the motor spindle. A Non-Return Valve (NRV) is
located in the hose, near the motor, and prevents fluid returning to the reservoir.
The motor spindle is a conventional design with a taper spline location for the wiper arm and a threaded shank to secure

the arm to the spindle.

The wiper arm is similar in design to the front wiper arms. The arm attachment hole has tapered splines, which mate with
the splines on the wiper spindle. The arm is secured to the wiper motor spindle with a nut. The wiper arm has a pivot
point, close to the spindle attachment. A tension spring is connected to the wiper arm on each side of the pivot point and
applies pressure to maintain the wiper blade in contact with the windscreen.

The wiper blade is attached to the wiper arm with a clip that allows the blade to pivot.

 

If the rear has any splines on that spindle they must be very thin.

The LR3 Mechanic told me if that rear nut get just a little loose it will get floppy. The tighter that bolt the more pressure from the the shallow splines. If they were to move they would most likely shave a little bit of metal off the inside of the wiper arm hole.

They are not so large so the wiper would not slip with enough force. This prevents it from breaking with extreme force. It will simply slip. The worst that happens is you have to tighten the bolt more.

Here is a video that illustrates that the spline is nothing more than a tapered shaft with extreamly fine spline teeth that add grip when you tighten the bolt. Basically a friction fit with a little roughness from the fine spline teeth. Not large splines that many may have imagined.


If it were made like the spline below damage could easily occur as it would be too strong a connection.
[IMG]https://landroverforums.com/forum/<a href=http://s667.photobucket.com/user/RJ072/media/splines.jpg.html target=_blank>

 

What you say and have discovered makes sense. It may be that the LR Engineers are smarter than one thinks. Yes, the splines are small but they probably also have made the splines on the motor shaft of a harder material than the wiper arm. As such, the arm would fail first and replacing the arm would be a less expensive fix relative to motor replacement.

I would say that I have learned something here. Your research is appreciated.