Does anyone have a source with stock for these, specifically LR or Dunlop I suppose are the descent ones?
Front Height Sensor: ANR4686
Rear Height Sensor: ANR4687

Mine are still ok, but getting on, and I suspect there might be a bit on a dead spot on my left rear (haven't confirmed). Anyway, I'd like to keep using the vehicle for many years to come so I'm looking to replace them all preemptively and keep the currently fitted ones as spares.

I can't find any stock locally (South-Africa) and most of the UK online retailers show out-of-stock.

Thanks!
Justus

For the fronts, Island 4x4 have either Eurospares https://www.island-4x4.co.uk/front-height-sensor-9702-anr4686g-p-336.html or Dunlop https://www.island-4x4.co.uk/front-height-sensor-9702-dunlop-anr4686-p-42133.html, both shown as in stock. They also have Eurospares rears, https://www.island-4x4.co.uk/rear-height-sensor-9702-eurospares-anr4687-anr4687es-p-42183.html but no Dunlop or OE while Craddocks are showing low stock https://www.johncraddockltd.co.uk/anr4687-genuine-p38-rear-suspension-height-sensor-from-va345920.html.

Thanks Gilbert!

Your searching skills are definitely greater than mine! Any thoughts on the quality Eurospares units?

Probably because I am using Google.co.uk so find local hits rather that you being forced to use a local search. I have the same problem when I am out of the UK finding stuff as Google always tries to give me local results.

I suspect Eurospares do much the same as Britpart and buy them in from other suppliers, maybe even OE. Given the choice of multiple suppliers I tend to go for the mid range ones, not genuine (as you seem to pay a 200% premium for LR packaging), not the cheapies as they are likely to be Chinese make knock offs so by going for the middle you are likely to get something decent. I've bought some Eurospares stuff and not had a problem but not height sensors I will admit.

I've a quite a bit of trouble with the Eurospare ANR 4687 but only on the rear RHS. I have one fitted on the rear LHS with no issues. This is the rear height sensor for 97 on cars where the same sensor is used both sides. On the LHS these seem fine, but the bit count compared to OE is slightly off and just on the tolerance of the controller before error. So if you have OE and Eurospare on the rear axle you can't get exactly level. This forces buying a Eurospare sensor for both sides. I'm on my third RHS Eurospare sensor trying to get a sensible reading on the rear RHS - it seems when the same sensor is reversed that part of the pot track isn't correct and gives false readings and confuses the controller. Three brand new Eurospare sensors have caused this whereas if I fit the old OE part there's no issue. Quite strange. Any tips or ideas appreciated. It's not possible reverse the RHS sensor - run leg forward otherwise I'd try this.

Due to the way they are bolted in, it isn't really feasible to enlarge the mounting holes to allow you to adjust the position of the sensor to get the readings to match. You might be able to do it by bending the arm until it matches with the one on the other side?

My brother and I are in the process of designing replacement height sensors based on modern, contactless potentiometers. So no more mechanical wipers to wear out internal to the height sensor.
We should have the proto set fitted to a P38 in the next few weeks.

That would be awesome. Please update us on here.

Gilbertd wrote:

Due to the way they are bolted in, it isn't really feasible to enlarge the mounting holes to allow you to adjust the position of the sensor to get the readings to match. You might be able to do it by bending the arm until it matches with the one on the other side?

I'm very grateful that Eurospare make these sensors for us, but it's something to do with the RHS rear reversed position readings. With the OE part temp used on the RHS rear (along with Eurospare on the LHS rear) I've bent it slightly to get it as close as possible, and the heights almost match with no errors and a bit count diff of 3. Maybe I have to buy another OE for the rear but I wanted to solve and find the Eurospare issue.

PaulD4 wrote:

That would be awesome. Please update us on here.

New, 3D printed arm in development:

The plan is to fully 3D print the arm from an engineering filament with good wear resistance, mechanical strength and temperature resistance. This will make the arms cheap enough that you can have a spare set kicking around in the car for when an errant branch rips one off. No need to replace the expensive sensor in that case, only the damaged arm.

Small resistor on either side?

Some years ( or decades) ago a member on the other side installed some potentiometers to compensate for side tilt.

th.

We did some articulation testing over the weekend to check that we got the appropriate range of motion out of the new sensors and arms with no binding etc.

This version worked well.

Looks a very nice job to me. In theory the only weak point now would be the electrical connections as there's no physical pot and wiper to wear. What is that you've used to secure it to the trailing arm?

The joint to the trailing arm is just a little assembly with a bolt through the middle. I never liked just forcing the existing arm through the rubber mount so this is a little more elegant:

Sadly the sensors of the type we have chosen are quite new, so not all potential variants are currently available. It means that we needed to design some interface electronics that will intercept the height sensor readouts, adjust them to make the EAS controller happy, and then send them on. This sensor interface board will be mounted between the EAS and Gearbox controllers. It does add flexibility in that if the Piher sensors we have chosen to base this design on are for some reason not available, then we can just adjust the software for whatever sensor is available.

I do quite like the sensors we have chosen, their IP69K rating and contactless operation makes them ideal for this application.
This is the sensor we are using for the first proto set: https://www.digikey.co.za/en/products/detail/amphenol-piher-sensing-systems/HRPS-F-180S-05-A/18739029?s=N4IgTCBcDaIBICUAKBlAtAMTQRgBwAZ18BWNAQRAF0BfIA

I love the new EAS driver pack. For quite a while I've been running with one that uses an Arduino and six MOSFETs for the PWMing but it's nothing like as fancy as yours!

I am very pleased with the driver pack design, it came out good. To be honest it isn't much more than an Arduino with some fancier solenoid drivers that handle the PWM part themselves, all packaged in a pretty box.

Did some range of motion testing on the front height sensor arms this evening.

Full droop (shock disconnected):

Full compression (bumpstop compressed):

I think we'll adjust the twist of the arm in relation to its mounts a little and retest.