Self leveling headlights

[Robster68]

I’ve removed the front unit but the headlights still go up and down when I turn on the lights,also as I understand it there’s a unit on the back,can anyone explain this?

[bigwinn]

Similar principle on the rear suspension

Look underneath past the diff you’ll see it

[Robster68]

Similar principle on the rear suspension

Look underneath past the diff you’ll see it

I’ve seen it mate,I’m just trying to figure out why self leveling seems to work with front unit removed.

[bigwinn]

It will still get movement as the two armatures work in tandem

[Robster68]

It will still get movement as the two armatures work in tandem

Ok great,at least I know the rear unit is working,will fitting a new front make any difference?

[enuff_zed]

It will still get movement as the two armatures work in tandem

Ok great,at least I know the rear unit is working,will fitting a new front make any difference?

In the UK it will prevent it failing the MOT.

[Robster68]

It will still get movement as the two armatures work in tandem

Ok great,at least I know the rear unit is working,will fitting a new front make any difference?

In the UK it will prevent it failing the MOT.

I’ve already got my control technique so no worries there,new unit has been ordered so will report back when I fit it,I just find it odd self levelling still works with unit disconnected

[enuff_zed]

I suspect the self levelling works by sensing the difference between front and rear.
With the front disconnected, the system will sense the rear depressing, assume that it pointing the lights up, and level accordingly.
The same principle would apply if only the front were connected.
What it cannot now do is allow for the whole car moving down.
If you were currently to load the car evenly so that it sank equally front and rear, only the rear sensor would register any movement and the car would wrongly assume that it is rear end low and lower the lights to compensate.

[Robster68]

I suspect the self levelling works by sensing the difference between front and rear.
With the front disconnected, the system will sense the rear depressing, assume that it pointing the lights up, and level accordingly.
The same principle would apply if only the front were connected.
What it cannot now do is allow for the whole car moving down.
If you were currently to load the car evenly so that it sank equally front and rear, only the rear sensor would register any movement and the car would wrongly assume that it is rear end low and lower the lights to compensate.

Great explanation thank you,lt makes sense really.
The cars still on jack stands awaiting parts to finish the front end,will be interesting to see what difference new unit makes.

[enuff_zed]

I suspect the self levelling works by sensing the difference between front and rear.
With the front disconnected, the system will sense the rear depressing, assume that it pointing the lights up, and level accordingly.
The same principle would apply if only the front were connected.
What it cannot now do is allow for the whole car moving down.
If you were currently to load the car evenly so that it sank equally front and rear, only the rear sensor would register any movement and the car would wrongly assume that it is rear end low and lower the lights to compensate.

Great explanation thank you,lt makes sense really.
The cars still on jack stands awaiting parts to finish the front end,will be interesting to see what difference new unit makes.

Cheeky question (ask me how I know), but was it the dropping of the front wishbone on full extension that broke the existing unit?
Be sure to jack the suspension up a little before you fit the new one.

The extra downward movement afforded by removing the strut unit is enough to break the levelling unit arm...................... or so I'm told, ahem.

[Robster68]

I suspect the self levelling works by sensing the difference between front and rear.
With the front disconnected, the system will sense the rear depressing, assume that it pointing the lights up, and level accordingly.
The same principle would apply if only the front were connected.
What it cannot now do is allow for the whole car moving down.
If you were currently to load the car evenly so that it sank equally front and rear, only the rear sensor would register any movement and the car would wrongly assume that it is rear end low and lower the lights to compensate.

Great explanation thank you,lt makes sense really.
The cars still on jack stands awaiting parts to finish the front end,will be interesting to see what difference new unit makes.

Cheeky question (ask me how I know), but was it the dropping of the front wishbone on full extension that broke the existing unit?
Be sure to jack the suspension up a little before you fit the new one.

The extra downward movement afforded by removing the strut unit is enough to break the levelling unit arm...................... or so I'm told, ahem.

Not cheeky at all mate,that unit had been on there since new I think ,it didn’t stand a chance,basically the screw to the wishbone was welded on near enough,galvanic corrosion I think you call it.

[smorris_12]

I just find it odd self levelling still works with unit disconnected

These look like the same sensors they used on the Disco II for the self leveling suspension. When they died the suspension would simply end up at one end of its travel or the other so I don't think there's any idea of implausible values in their design for the control circuit to make use of.

[Robster68]

The front sensor is replaced so thought I’d have a crack at the rear sensor,god knows how this worked plastic arm bushes totally seized deforming plastic arm.I managed to removed it without breaking the sensor arm this time,took everything apart on the bench freed the bushes,now to clean and paint all metal brackets and hopefully I can save the deformed plastic arm leaving it in a vice for a few days.

[grannyknot]

It looks like you can still buy that push rod if your repair doesn't work out.

[Robster68]

Wow that’s surprisingly cheap,I’ll pick a new one up on my travels.