self levellers
 

Just failed the mot due to several things but the real puzzle i would like help with is the rear self levelling sensor. The tester states its missing and technically he is right. Sensor is screwed to the sub frame but its not connected to anything due to the double ended pivot arm being absent, however there is no bracket on any part of the suspension for it to connect to. In addition i would say its not been connected for years, its rusted/ corroded into a blob of plastic/metal, so can the levelling sensor at the front do the job on its own??? Opinions on how to proceed appreciated.

If you place a heavy load at the rear of the vehicle it will have only a small effect on the front suspension, but rather more on the rear!

So no, you need both.

I think I'm correct in stating that originally there was only a front level sensor (hope someone else can confirm this fact), the rear unit was added to later models, sorry don't have any cut-in dates; the sensor part numbers (which are E39 'ish BMW items) are different for front and rear.
If you want to try and 'cheat', remove the rear mechanism bits that still remain, tape up the sensor electical link out of sight and go somewhere else for your MOT (ensuring the front sensor does still operate properly).

thank you chaps, I have gone down the replacement route, the rear sensor was shot and had a bmw part no so thats on its way, and the missing link is ordered from a supplier of adjustable connecting rods that have excellent reviews. I will fabricate a new bracket for the upper arm fixing point , so will post how I get on.

Not sure if these might help or not but here are pics that show the bracket on the upper arms I changed out on mine. I also changed the sensor as the arm was seized solid and the sensor itself split open. I dropped a dod of white grease in the new ones joints and threads before fitting to reduce the corrosion on it

https://www.the75andztclub.co.uk/for...31256d7598.jpg

https://www.the75andztclub.co.uk/for...410a3a3c8b.jpg

I know that I need to replace the rear level sensor on mine as it appears to be seized and the plastic arm is all twisted, it doesn't seem to have affected the levelling though.

Funnily enough, put my car in for service/MOT yesterday and they found the front levelling sensor arm had become disconnected so reconnected that before testing. Haven't done a lot of night driving recently to have noticed that the beams would probably have been on the default setting, which is dipped right down - unless it had become disconnected in the mean time.

[QUOTE] I know that I need to replace the rear level sensor on mine as it appears to be seized and the plastic arm is all twisted, it doesn't seem to have affected the levelling.

The levelling is done by the special dampers, the sensors are required to set the headlight assemblies to the correct functional positions.

[QUOTE=KWIL;2903736]Yes, I meant headlamp levelling/aim. My Volvo 740 estate has self levelling dampers on the rears (Nivomats, which are very expensive to replace) I don't know if self-levelling dampers were fitted/an option on tourers? If they were I suspect that they are a lot more expensive than standard ones.

I'm sure that the headlamp levelling is only fitted to cars with Xenon headlamps, manual load levelling is fitted to normal headlamps I think (not sure about projectors)

thanks chaps, the pics are a real help. after a bit of poking around i realise the bracket is partially still fixed to the arm, its just broken off where the sensor arm joins it, probably due to the arm seizing. with it all off I think its been like this for at least 2 mots but the latest tester has been more strict maybe. anyway it will be back working as soon as the new bits arrive. rather you than me changing those upper arms, luckily my originals seem pretty solid.

It's important that the links make an 'open' triangle with the suspension or it won't operate correctly. Here's an archive photo of the rear one correctly fitted.
https://www.the75andztclub.co.uk/for...4706d0649e.jpg
-and the front one 'flipped' and inoperable.
https://www.the75andztclub.co.uk/for...dc4f7dc34f.jpg
Source of images in this thread: https://www.the75andztclub.co.uk/for...ad.php?t=21583
TC