90 front wiper wobbles, backlash, random, no park, oversweep - solved at last

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skint-as-usual

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Posts
2,411
Location
County Durham
Issue
When I bought the 90 the front wipers did not work very well, there was lots of backlash; you could move both wipers by hand through a large arc. When the column switch was used there seemed to be total random wiping action, some stuttering, some over sweep (if the blades had not stuttered by then).

You could only manually judge the park by the use of the flick wipe to actually park the blades at a sensible position, otherwise they would just stop anywhere on the screen when the stalk switch was turned to the off position.

The column stalk itself had issues: it had apparently 5 settings:
Speed 2
Speed 1
Intermittent
Off
Flick

None of which worked (except for the off). Speed 1 and 2 needed excessive effort just to get the stalk switch up there.

History
OK. I admit it has taken me 27 months to fix this, but heyho. Mind you other stuff more important than wipers came first, steering box leak, radius arms, steering linkages, rebuild gearbox, replace the transfer box, new clutch etc – and I only have so much money to spread around J

I got ‘round to looking at the wipers in the “summer” of 2012. This was mainly forced on by the terrible rain when on holiday, where it seemed to monsoon for 2 weeks solid.

And the fact that Driving North towards Buxton on the A6 in the rain the driver’s side wiper arm fell off the splined spindle. (Bu&&er). Lucky I managed to stop before the arm and blade fell off the bonnet. This was fixed as temporary by the use of jamming half a match stick in between the splined “top hat” thing and the splined cup bit on the wiper arm, hitting with a hammer to secure.

OK, time to get this all fixed then,

Wobbly wipers
Need to remove all wobbles & random wiping, need to replace all splined parts as there were no splines left at all on either the arms or the “top hat” things

Therefore purchase new:
1no Land Rover Defender Front Wiper Drive cable RTC202
2no Wiper splined adaptor drum STC987 (the top hat things)
2no Front wiper arm - Right Hand Drive PRC4276
2no Wiper Wheel Box Assembly PRC8495
2no Wiper Blade 90/110 13" (was prc8599)

Was in Birmingham by then on holiday still, so ended up paying Stealer prices.

Ripped out all of the top dash bits etc as needed to access wheel boxes, wiper motor. See also busterbus excellent article here http://www.landyzone.co.uk/lz/f41/wiper-boxes-cable-renewal-99743.html

… and were the “top hat” things allen keys rusted in? – Yes they were.

Time for some pics

:nopics:


What is the use of a fred with no pics??


Access to the wiper motor (someone has been here before and stripped it out – lots of spanner burrs on the wiper motor ¼ inch (from memory) cover bolts). Shown with park switch slid off.
image 1 here

1_zps4a6ee85a.jpg



All bits out of the way:
Image 2 here
2_zps196177ff.png


Old wheel boxes
Image 3
3_zps5633a625.png


Look at the lack of helical thread on the old drive cable – no wonder wipe was so random:
Image 4 here

4_zps83125c8a.png


The old “top hat” things no splines to grip an arm:
Image 5 here

5_zpsc2bfc489.png



Now look what happened to the new drive cable, I had to drive in the rain with the window down as it was too long and when the wipers worked it crashed into the driver’s door window. I had nothing then to crop it with (cable cutters were at the caravan & I fitted this lot at first to get by in the stealers car park).
Image 6 here
6_zpse2b7210f.png


Ahh look, new wheel boxes, “top hats” and arms – luxury
Image 7 here
7_zps6d279572.png


Compare – no prizes for guessing the old wheel boxes – and look at the warp on one of them:
Image 8 here
8_zps37cb7051.png


.. and yes it was still raining.

Fitting new boxes:
Image 9 here
9_zpscee05d97.png


With loads of grease:
Image 10 here
10_zpsf487055d.png



Greased up everything too, and the drive cable too:
Image 11 here

11_zps1b057d78.png



New “top hat” things that actually have splines:
Image 12 here
12_zps8d4ec873.png

Now all I need to do is get it all working.

Blipped the flick wipe and aligned the wiper arms:
Image 13 here
13_zps575242c7.png



Looks good so far?

No.

What happened was over sweep. This must have been lost under all of the backlash and random stuff. Now I have a crisp system with no slop look what happens to the sweep:
Image 14 here

14_zpsda5424fe.png


At this stage cannot do anything about the over sweep, so let us move on.

Wiper park
I fitted a new
1no Park Switch 520160
To the wiper motor.

Did this work?

Not exactly, the wipers parked at the overswept position see above pic – more bu&&er.

Look at this:
Here is the park switch with it’s actuating pin (it is just a glorified micro switch)
Image 15 here
15_zps31aaec16.png


Discussion of wires, functions and colours may come later

So when the wipers are going to park a cam needs to come around to push the pin and turn the power off to the motor.

Here is a picture of the cam (white plastic bit) in the correct park place as viewed with the park switch removed:
Image 16 here

16_zps8134d8b3.png


It lives on the back of this in the motor:
Image 17 here

17_zps8bcd0932.png


Mind you do not drop any circlips or this will f*&k up everything

Here it is as shown on the cog thing (AKA MOTOR CRANK GEAR )-inside the motor:
Image 18 here

18_zps9a1671d3.png


****ty picture but the white plastic thing does activate the park switch.

So why park at the over swept position?

Because some ignorant PO has fiddled? – This actuating cam can be positioned 180 degrees across the cog thing (see holes as above). All I had to do was move the white plastic bit to the 180 degree position and the wipers parked as you would expect,

RESULT

Big J



Wiper over sweep

Ok lets look at this now
These wiper motors and bits were used commonly throughout the British motor industry from the 1960’s say. The same design was used in Mini’s, series III’s rover cars etc.

Let’s use the same on a 1989 land rover 90.

No probs with that – the design is proven and works.

However different vehicles need different sweeps of the wipers, mini to 90, say.

There is no adjustment in the motor, what this lock nut and adjusting screw on the wiper motor does is beyond me at the moment:
image 19 here
19_zps4590d6aa.png


..and honestly can I be bothered at the moment to investigate? No

Update number 1:
It may be something to do with this:

shaft-end-float_zps3c6b707f.jpg

Though what armature shaft end float actually is and why it is important is not stated.

Update number 3:
Windscreen wiper motor
Make/type; Lucas 14W uprated two speed
Armature end float: 0,1 to 0,2 mm
Brush length, minimum: 4,8 mm
Brush spring tension: 140 to 200 g

Getting there!





So look at the wiper motor crank gear as fitted (detail copy of previous picture):
Image 20 here

20_zps0a637cb5.png


Look, under the grease it says 140

More B&&er – it is a 140 degree crank gear which gives the following effect (sorry fir the ****e graphics, this PC a’int the best for good software):

Image 21 here
21_zps408c26c5.png

What we need is this, a 115 degree sweep:
Image 22 here
22_zpscb230e4d.png

Look what we have here:

Purchase
1 no LAND ROVER SERIES 3 WIPER MOTOR CRANK GEAR - 517646

Image 23 here

23_zps6ca20527.png



Look, it even says 115 degrees on the cog, and it comes with washers and circlips too

Update number 2:
Here are some images of the old and new Motor Crank Gears:



IMG_1389_zpsbecc3f53.jpg



IMG_1390_zpsb9f6c888.jpg



Wiper switch

OK, nearly there. Last thing to replace the ****ty and wrong wiper stalk with the correct one:

1 no WASH / WIPER SWITCH - LANDROVER DEFENDER to GA455945 PRC3900

This is true to the vehicle as it only has:
Speed 2
Speed 1
Off
Flick

I can see no evidence that my 90 has ever had an intermittent relay or fixings.

Fitted with only minor hassle, could not remove the steering wheel to gain good access to the ¼ inch bolts.

More success = all appears to work


Aside on wiper motor wiring, colours of wires and stuff:

Perhaps an update tomorrow, it is late and am tired

Brief update on cables to the wiper motor:
For a Lucas 14W (without the intermittent relay and harness) it's along the lines of:

5 pin connector at the wiper motor end
Pin 1 Ground (B) to motor coil Blue from memory
Pin 2 Park (NLG) to park switch
Pin 3 Fast (ULG) to coil fast yellow
Pin 4 IGN (G) to park switch
Pin 5 Slow (RLG) to coil slow red



What next? – Fit one of these to get the wash water to the correct place on the windscreen, cos I am getting none on the drivers side

Land rover Defender Front Washer Jet Twin Nozzle PRC5736

All sorted?


No, the dash board is next (no instrument lights, they have all burnt out and melted the bulb holders for a start), followed by ………
 
Last edited:
This couldn't have come at a better time for me. My wipers packed up completely the other morning on my way home from work. They had previously displayed lots of the symptoms described in your post (not parking correctly, random stops and starts etc). This should help me out a lot with fixing them.
 
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