Thicker spring pads/shims to raise the front a touch?

[Bolle]

I think I read somewhere that in theory you could 'double up' the spring pads, so one on top, and one on bottom of spring? Don’t know if that is correct?

Adding 2.5mm with either the E9x mount or reinforcement plate will help and might fully elliminate it.

I was thinking maybe both, although the E9x top mount seems to be a lot thicker and thus removing the need for reinforcement plates? But as mentioned earlier. I’d prefer to raise the car between the spring perches to reduce compression and increase travel of the B4 shock.

 

[TriggerFish]

Part ending 5590 is now NLA though, according to these guys.

Search results

BMW genuine parts shop. Order your BMW Parts and Accessories at Rybrook Warwick.

www.online-parts.co.uk

But then, these guys still list it...

www.sytnerstevenagebmwparts.co.uk

I think I read somewhere that in theory you could 'double up' the spring pads, so one on top, and one on bottom of spring? Don’t know if that is correct?

I was thinking maybe both, although the E9x top mount seems to be a lot thicker and thus removing the need for reinforcement plates? But as mentioned earlier. I’d prefer to raise the car between the spring perches to reduce compression and increase travel of the B4 shock.

While I know it's not what you are suggesting, you definitely would not want to put 2x 10mm at the top of the spring. While you could double up the pads at the rear, it wouldn't be wise up front due to the way they sit.

They are different top to bottom, but if could find a thicker bottom one too, I see no reason why this wouldn't be ok.

 

[TriggerFish]

Part ending 5590 is now NLA though, according to these guys.

I just spoke to my local dealer - 31331135590 (10mm pad) is not NLA, but is not available/not in stock, and there's no date stating when it will be available again. So it's unobtainable right now, but it might change at an unknown date in the future.

There is a 9mm spring pad, which is readily available instead, though.

 

[Bolle]

I just spoke to my local dealer - 31331135590 (10mm pad) is not NLA, but is not available/not in stock, and there's no date stating when it will be available again. So it's unobtainable right now, but it might change at an unknown date in the future.

Of the three part numbers @Meds mentions, I can find 31331135589 available online here in The Netherlands.

While I know it's not what you are suggesting, you definitely would not want to put 2x 10mm at the top of the sprin

I meant one pad on top of the spring, and one on the bottom perch. I was led to believe you could use them on both perches, but I might have been misinformed.

 

[NaweedM]

I meant one pad on top of the spring, and one on the bottom perch. I was led to believe you could use them on both perches, but I might have been misinformed.

I solved my sagging issues with my B4+Eibach Pro by using an E34 perch for my front springs, going from 3mm to 9mm rubber on the front (earlier in this thread i was contemplating on ditching the original Z4 rubber as it was too thin), you can see the before and after below however, the rear was really bad. It was like the car was squatting the whole time. for Dutch roads its not bad but when it came to speedbumps, it was a nightmare.



Solved that by using the same idea I had with using E34 front perches, but decided to take some measurements on the rear to decide the thickness of the rear rubber perch. The original Z4 rear spring perches (or onderlaag voor veren in dutch) was around 5mm which i found a bit crazy. I settled for 14.5mm rubbers from an E46 with "rough terrain" package for its suspension. These were rather expensive from the dealership for thick discs of rubber....



All in all, it solved my issues with strange ride height. I know once my front and rear bushings are refreshed, it will probably negate everything i did here however, I have no plans to refresh bushings as of now.

Currently the car sits absolutely perfect with Bilstein B4+Eibach Pro's



9mm front spring top perch - 31331128522
14.5 mm rear spring top perch - 33531094754

 

[TriggerFish]

I solved my sagging issues with my B4+Eibach Pro by using an E46 perch for my front springs, going from 3mm to 9mm rubber on the front (earlier in this thread i was contemplating on ditching the original Z4 rubber as it was too thin)

That sits perfectly now - you're right!

On the spring perch - was that 31326769667? Did that raise the front of the car for you?

 

[NaweedM]

Part 31331128522 indeed rests against 31326769667 as you mentioned. It raised the front by 6mm.

The beauty of the E85 platform is that you can mix and match some of these parts from other BMW's as they just have thickness differences
On real OEM it is the part below, but non Z4 variant

08	Spring pad upper

 

[Bolle]

Great to see more people (especially Dutchies ) looking into this route!

I’m just slightly confused in terminology and part numbers now... Trying to figure it all out as I’d like to order all needed parts in the coming few weeks.

If I look at a E85 front strut assembly from RealOEM



What I understand:

The spring perch refers to to metal plates on both side of the spring. The bottom one is part of the front shock, the top one is no. 07 in the diagram. In the E85 diagram this is part 31331135580, but the previous post refers to 31326769667?

The spring pad is the rubber spacer part no 08 in the diagram. For these you can get 10 mm thick ones as per @Meds post 31331135590, 31331134382; 31331135589. Or the 9 mm one E34 one 31331128522 as mentioned in the previous post.

Also good to hear that for the rear the 14.5 mm pads 33531094754 are recommended to avoid any ‘droop/squat’ from the rear. BMW indeed charges an arm and a leg for these. I found these alternatives that I might give a shot.

Rear Upper Spring Shim Pad 14.5 mm 33 53 1 094 754 for BMW E46 325Xi 330Xi SET | eBay UK

All parts purchased from DeutschepartsUSA carry a full unconditional one year warranty from date of purchase to be free of all defects in material or workmanship. Should a part fail within the twelve (12) month warranty period, DeutschepartsUSA will provide an immediate replacement of the part...

www.ebay.co.uk

 

[TriggerFish]

The spring perch refers to to metal plates on both side of the spring. The bottom one is part of the front shock, the top one is no. 07 in the diagram. In the E85 diagram this is part 31331135580, but the previous post refers to 31326769667?

31326769667 - I think this was some confusion caused by me and Naweed.

Look at my post where I quoted Naweed, and it says 'E46 spring perch'. I took this to mean 31326769667 - the metal perch, not the rubber pad.

The post was then changed, and now reads "by using an E34 perch for my front springs, going from 3mm to 9mm rubber", so the E46 bit was probably a typo that I then searched for. Unless Naweed says otherwise, I think we can ignore 31326769667/the E46's metal upper perch.

FWIW, I am going for:
- E9* xi top mounts: https://www.autodoc.co.uk/sachs/7883596
- E30/E34 9mm spring pad: 31331128522
- +9mm spacers in addition to the rear spring pad: https://www.ebay.co.uk/itm/251742456729

I'm hoping that'll be enough to make the B4 extend to it's (mostly) full length, and have a good stance.

 

[NaweedM]

I should have verified the metal part before quoting it.

To conclude, all height increases were done by using different thickness rubber parts from other various BMW models of this same generation, since the molding shapes are shared across these platforms. All metal parts are as is from the E85 realOEM when I did my Bilstein B4+Eibach pro upgrade. I did not swap these out from other models as some of them had slightly different notches, camber pins and etc that introduces too many variables. I was able to achieve a satisfied ride height by using thicker front rubbers and rear rubbers.

 

[Bolle]

So, I’m still investigating the way to go.

I’m either going for Eibach/B4 with thicker spring pads as the ‘cheapest’ decent option. Or ST XTA coilovers as a more ‘high-end’ oprion - these are adjustable in height and hardness, so hopefully able to get a controlled but somewhat comfortable ride. Feedback from users also lead me to probably use the EIbach Pro-Kit springs in the rear, as these might be better for road use than the ST ones. And as springs are seperated from shocks in the rear, not too hard to do.

While figuring all this out, I added it all up in costs. As the coilovers (especially front) have a lot of parts already on them, although they are more expensive, that offsets some of the cost.

In my little spreadsheet in the Eibach/B4 scenario you can of course save a bit by re-using some stuff coming off the car, but I think most of the more expensive items (top mounts, drop links) need to be replaced anyways so savings would be limited. And I priced this out using an online BMW parts dealer, you could easily save some 150 eur or so using more stuff from Autodoc etc.

Taking that into account I think you can get an Eibach/B4 setup for approx 1.050 eur, and a ST XTA setup for around 1.550 eur. But I need to buy a mcpherson spring compressor for around 100 eur to assemble the B4’s (the ST’s come assembled), so you end up at around 400 eur difference.

Of course you could go for cheaper coilovers, say the ST X series at around 800 eur but then you need more mounting hardware (top mounts etc), so the savings are less than they appear, and you loose the hardness adjustability which might make them too hard for daily street use.

Some thoughts to ponder over!

 

[TriggerFish]

Here's my findings, if it helps at all.

I used the parts as per the photos, but it's E9* xi top mounts, E85 spring perches + lower spring pad + 9mm top pad (from the E30), B4 shock and Eibach Pro spring.

Keep in mind this is a brand new spring, and I don't know how old the spring on the other strut is. I suspect it's quite old, as while the shock has been recently replaced, the previous owner was clearly a tight git and didn't replace the other shock or the bump stop/dust cover, or - judging by the grinding it makes - the top mount. Therefore it's probably sagged down a bit. The old strut is meant to be M-Sport. I have to assume it's got the correct springs.

	Old	New
Distance between lower spring perch and top spring perch	20.45cm	24.1cm
Distance between lower spring perch and top mount	20.4cm	24.7cm

So I'm currently 6mm above M-Sport height with the Eibach Pros. I suspect once a bit of settling in has happened to the rubber pads/spring, it'll be essentially M-Sport height - or as near as makes any visible difference.

Here are some photos, for reference.

Comparison

Look at the new top mount - loads of reinforcement there, which can't be a bad thing. Longer studs too, so good for strut brace fitment.



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