Jump to content
hunter

E39 Sedan rear suspension levelling

Recommended Posts

My E39 (like my E46 before it) has a ~9 - 10mm difference in ride height between left and right, the right rear being lower.

I know it's "normal" and according to BMW "in Spec" and probably due to gas tank, battery and driver all on the one side, however it bothers me.

On the e46 I had a local suspension shop make a spacer for the spring (which is seperate from the shock) in the E39 the shock and spring are configured in a "coil over" set up, making it a bit more difficult (?)

Has any one resolved the issue described above? IE  i'd love to get a 9mm (edit) of lift with a spacer in their somewhere to level the rear out.

I dont have the desire to go to coil overs.

 

Edited by hunter
clarity

Share this post


Link to post
Share on other sites

Nah, it makes it easier:

You can buy "rough road version" rear upper shock mounts, with longer studs fitted (you can also fit longer studs, but why not replace the mount). BMW had factory fitted spacers on the top for rough roads.

I machined up a plastic spacer to go on the top, to lift our E39 with the Mtech suspension.

Be aware, that you probably only want a 5mm (maybe 6) spacer to lift it 9mm though??? rough enough is probably OK anyway - it's always going to be a bit either way, depending on load etc.

I think I used 10mm spacers and got maybe 16 or 18mm of lift??? - the suspension pivot is about halfway between the outside of the wheel and the inner arm mount - mathematically, you'll get double the lift for the spacer thickness, but the leverage reduces it slightly.

Share this post


Link to post
Share on other sites
11 hours ago, Allanw said:

 

You can buy "rough road version" rear upper shock mounts, with longer studs fitted (you can also fit longer studs, but why not replace the mount). BMW had factory fitted spacers on the top for rough roads.

I machined up a plastic spacer to go on the top, to lift our E39 with the Mtech suspension.

 

yeah cheers, @Allanw i did a bit of research on the rough road version but cant see how much taller it is than stock anwhere, have asked my local dealer if they know.

Where did you sit the spacer you made? right at the top of the assembly? mine has M Tech 2 suspension . 

Share this post


Link to post
Share on other sites

Yeah, my spacer just slipped over the studs on the top mount. It was much thinner than the rough road version.

Once you have the long studs in there, you can adjust thickness easily... but it just takes a bit of time  lower the shock/spring assembly after removing the rear parcel shelf.

Entirely from memory, the rough road version raises it 22mm???

I also raised the front of ours, which was a 10mm alloy ring, tapped so the studs were replaced with bolts, bolting the top mount to the spacer, and the extra length of the bolts from the studs to bolt it to the shock tower (plus I had a cheap strut brace to reinforce the soft shock towers). You can't get away with that on the back though, I don't think the bolt heads fit? I also wanted to make it all, before stripping the car anyway. You *may* be able to find replacement studs the right length, but the knurled part isn't always a standard diameter.

I don't have a pic of the back, but this is the front, same basic idea, just slightly different execution:

6945697689_2c47ac4f1b_z.jpg

And this one is of it raised, which I don't think I quite achieved 20mm from original:

16498446363_5f88ea51fe_c.jpg

  • Like 1

Share this post


Link to post
Share on other sites

Thanks Allan. Good info. 

Share this post


Link to post
Share on other sites

one thing i might try, is to get the left and right suspension swapped over to see if that levels it out theory being low vs high with weight on the swapped high side. 

  • Like 1

Share this post


Link to post
Share on other sites
1 minute ago, Eagle said:

Are you still on the original struts? 

Yeah mate. M sport 2. Quite expensive to replace so I’m wanting to try a few thing unless they are obviously shagged. Coombes checked a year ago at they reported no issues. 

Share this post


Link to post
Share on other sites

Probably are from my pov knowing what a refreshed E39 feels like. The strut mount rubber can compress over time along with the strut dampening weakening which can lower you.   

Share this post


Link to post
Share on other sites

Hmm ok. I’ll re measure myself and compare to previous measurements from last year. If it’s dropped further that’ll tell me. 
 

Share this post


Link to post
Share on other sites
On 4/30/2021 at 6:19 PM, Eagle said:

Probably are from my pov knowing what a refreshed E39 feels like. The strut mount rubber can compress over time along with the strut dampening weakening which can lower you.   

Height hasn't chnaged but is still uneven. i removed the wheels today to visualy inspect for obvious differences eg diff shocks. none seen other than both L and R rear guide links have torn bushings / boots so need replacaing. that also probably explans the loose feeling in the rear end / feeling or extra rotation when going around tight corners ( the car feels like its often slide when its not is the best way i  can describe it)

I do plan on swapping the shocks from left to right as mentioned above, while im doingthis i wil also replace all the bump stops and strut top mounts etc,

Cheers

 

Edited by hunter

Share this post


Link to post
Share on other sites

I would be replacing the struts with Bilsteins etc at the same time if you are going to strip everything down. Seems like a lot of work to do just to keep on using the originals which are most pretty worn at this point.

New mounts come that shim installed im fairly sure. The rear rubber shims and mounts hold up very well anyway.  Ive never seen one that has any real wear compared to new,  though i replace the mounts for piece of mind its all the front strut parts the usually fall to bits

Share this post


Link to post
Share on other sites

Cheers Eagle. Yeah I did a bit more investigation and see that the top mount has the shim installed. 👍

I’m  really in two minds about how much to replace when swapping the shocks over. On one hand it makes sense to me to refresh as much as possible as well as investigate the height difference. 
On the other I wait and replace it all at once after I’ve swapped shocks over and (hopefully) discover new shock will help fix me height issue as well as price of mind. 

I don’t want to put new static shocks in if it right away without knowing if it’s  going to help the height differential as well. If this is the case I’d rather go for something like a KW v2 so I can even out the height. 

I hope I’m explaining this clearly, still recovering from a concussion 🤕 and getting thoughts out clearly is a bit muddly 

Share this post


Link to post
Share on other sites

Yeah swapping a bit of pain but suppose it gives you some idea. Doing both set of rear arms is a good idea when you get new parts judging from your other thread. You need to remove the upper control arm anyway to remove the strut (easiest way imo) 

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...