Differing rear ride height, side to side (EDC) - The Unofficial BMW M5 Messageboard (m5board.com)

///Mster · 15th January 2007, 18:55

Can anyone give me some ideas as to why my rear ride height differs from side to side ('93 3.8 with EDC)?
Drivers (RH) side is about an inch lower than the passenger side.

I have checked the springs and they are fine (both exactly the same length). I have also just changed the drivers side strut for a spare I have and it's still the same.
There are no leaks at all (it did look like a possible small leak on the drivers side strut hence the change).
I am now assuming that the drivers side Accumulator/sphere has gone internally?
Anything worth checking before I commit to changing them? i.e. adjust the ride height? I assume this will adjust both sides though?

Has anyone found/fitted an equivalent Citreon part for the spheres? (Bentley's use them).

AlexA · 15th January 2007, 19:39

Quote:

Originally Posted by ///Mster

Can anyone give me some ideas as to why my rear ride height differs from side to side ('93 3.8 with EDC)?
Drivers (RH) side is about an inch lower than the passenger side.

I have checked the springs and they are fine (both exactly the same length). I have also just changed the drivers side strut for a spare I have and it's still the same.
There are no leaks at all (it did look like a possible small leak on the drivers side strut hence the change).
I am now assuming that the drivers side Accumulator/sphere has gone internally?
Anything worth checking before I commit to changing them? i.e. adjust the ride height? I assume this will adjust both sides though?

Has anyone found/fitted an equivalent Citreon part for the spheres? (Bentley's use them).

I don't think one shot accumulator would cause the difference in ride height, as they share the same pressure line. Still, it might be a good idea to change them if they are still original. I changed mine when the ride became bouncy. Not sure why you would want to use citroen accumulators though? I used Febi Bilstein ones (about £70 I think).

JED · 15th January 2007, 19:46

I had the same problem this time last year. It felt just like a shock had gone, and so changed a strut and both accumulators, however without any success. It turned out that the ecu for the edc had dropped a shock. You should be able to find a second hand one for £50.

Hopefully it is this as changing the accumuulators is a real pig, and if you do, remember to buy the hoses to the strut as these are more often than not coroded to the accumulator.

AlexA · 15th January 2007, 19:51

Quote:

Originally Posted by JED

I had the same problem this time last year. It felt just like a shock had gone, and so changed a strut and both accumulators, however without any success. It turned out that the ecu for the edc had dropped a shock. You should be able to find a second hand one for £50.

Hopefully it is this as changing the accumuulators is a real pig, and if you do, remember to buy the hoses to the strut as these are more often than not coroded to the accumulator.

Good point about the hoses. I changed both. And the job is a pig to do, probably not worth doing yourself.

Cyrus · 16th January 2007, 02:09

I just changed my springs from H&R to genuine brand new BMW ones specific to the car.

The front left is higher than the front right! What's the crack there???

It's a good inch difference too.

Sal

farrell · 16th January 2007, 10:27

All EDC equipped vehicles are lower on the rhs by 18mm.
Nothing to do with EDC control module generally.
When the EDC control unit has a partial control failure, the damper solenoids will default to control plane 3 (full hard) & the 180 kph spped limit warn may activate.

Springs are equally rated across axle pairs to vehicle chasis number.
Rear ride height is set in middle of vehicle via the tension rod from SLS accumilator to roll bar.
Thats not affecting the front ride height though.

How much extra mass is offset to the rhs of the vehicle centrline ?
Think big heavy componets

Farrell

Cyrus · 16th January 2007, 10:55

That's ok then.

With the rear ride height, is there a specific height for this or is it meant to be adjusted such that a certain amount of rear camber (or lack of) is set?

I've seen so many pictures of EDC cars which have different ride heights at the rear.

Sal

farrell · 16th January 2007, 10:57

KDS

Cyrus · 16th January 2007, 11:06

Last time I had it done the only thing they did was alter the front toe. That was with a much lower ride height.

I remember them telling me everything was within tolerances but the rear wheels had postive camber!

£90 was bloody expensive for just front tracking.

There seems to be lots of KDS places popping up everywhere with these new machines. Do they have a clue of how to alter rear ride height with these cars?...NO.

PMW it is again and this time I am going to take the specs with me as to what the front toe, camber and castor settings should be.

Sal

farrell · 16th January 2007, 12:18

Quote:

Originally Posted by Cyrus

Last time I had it done the only thing they did was alter the front toe. That was with a much lower ride height.

Thats good is'nt it

Quote:

Originally Posted by Cyrus

I remember them telling me everything was within tolerances but the rear wheels had postive camber!

Ask them to explain & what effect lowering springs has on the pre-programmed alignment & ride height specs for each specific vehicle

Quote:

Originally Posted by Cyrus

£90 was bloody expensive for just front tracking.

Was it ?
Go check what a stealer would charge m8

You can't adjust the front tracking unless you know what the toe & track of the front & rear wheels is relative to each other.
If you just had the front track done in isolation of the rear, the rear toe could be wrong & the front toe could be
aligned in isolation by winding the track rod ends over to one side of the vehicle causing the vehicle to crab.
See how quick tyres last then !

Quote:

Originally Posted by Cyrus

PMW it is again and this time I am going to take the specs with me as to what the front toe, camber and castor settings should be.

Sal

The specs for toe, camber ,caster & ride height specs are all within the machine.
Whislt PMW are not perfect, they do strive to make amends for errors.
They stand by what they do well & what does occasionally go wrong.

Due to Peters experience with setting up track related vehicles & the bald fact that he even aligns the cars
for the Subaru & mitsubishi dealers after repair or service, this one area where I am confident 100%
Just ask Peter himself to do it.

Farrell