Suspension Refresh

[tymhm]

So I've had my 95' 530i Touring for about a week now, and one of the first things I want to address is suspension. I'm planning on going with a Lowtec 45/30mm springs and struts package. I'm just wondering what else if anything I should replace suspension wise while I'm in there? I would think the spring pads (upper and lower). Should I replace the strut mounts? Bump stops? Specifically anything rubber.

The car is sitting at 97K km's, and was only driven Sundays by an old lady to church, but I know time and rubber don't go well together. I'd rather get things out of the way now, rather than 5 years later.

I know the question is rather basic, but looking at RealOEM diagrams made me a little confused. Getting parts for me is usually a 2-3 week shipping process, with expensive shipping so I'd like to get everything ordered at once, rather than having to place multiple orders.

[moroza]

Oh boy... how far do you want to go? I would consider a "full suspension rebuild", more or less what I did on my car in two major rounds of work (front and rear, namely), to include the following. I would also consider it very much worth doing; an E34 really is a very nicely tuned chassis when sorted out, apart from the steering. Done right, it's a big project, a big bill, and a great reward.

Here's an exerpt from my Expenses spreadsheet of most "footwork" items I've spent money on with this car.



Cost

What

Where

Notes



119
lower control arms
amazon (OC infiniti)
lemf germany


28
front brake pads
ebay
wagner usa


182
thrust arms, bushings, swaybar links
fcp
lemf germany, meyle turkey


47
tierods
autohausaz
febi spain


90
740 brakes; all calipers and front rotors
picknpull



250
front shocks, mounts, spring pads
fcp
sachs germany shocks, sachs usa V3 mounts, bmw pads


100
740 trailing arms with rotors, spring plates, brake hoses
picknpull



98
rtabs
eeuroparts
genuine


30
front bumpstops and bellows
rockauto
kyb germany


38
front brake hoses
ebay
ate germany


128
rear strut mounts, subframe mounts, rear spring pads
fcp
sachs china strut mounts, lemf china subframe mounts, oe pads


15
shipping returns to FCP
usps



35
shipping springs to cannon
fedex



-71
return from FCP
fcp
chinese lemf subframe mounts misadvertised and looked crappy


71
cannon springs
cannon racecraft



50
rear shock bellows and bumpstop
bartosh
oe and rein germany


505
tires
goodyear
comfortred touring chile


10
dot4 brakefluid
advance auto parts
carquest


75
rear sachs shocks
carter



28
ps hose
fcp
rein turkey


110
center subframe mount
fcp
genuine


32
brake rotors machined
oreilly



26
rear strut rubber
mcmaster



15
rear shock bushings
autozone
powerflex 8.9145


184
dogbones, subframe mounts
fcp
lemf germany dogbones, genuine (lemf) germany subframe mounts




Some notes:


Total $2195, not including my time. The only things outsourced were the tire installation and the spring custom work.
This includes a 740iL brake upgrade. I chose to also keep E32 rear hubs for a wider rear track.
I had a good center link and idler arm, and reused them.
Also reused the steerbox. It had play but a new one costs $WTF and is still sloppy, by all accounts.
Also reused wheelbearings, rear brake hoses, rear springs, rear brakepads. Maybe a couple other things I can't recall at the moment.
Thrust arm bushings I bought separately specifically to use the correct ones for a 525i - the blue cap. (https://www.bimmerforums.com/forum/showthread.php?2363605-OE-and-Lemf%F6rder-thrust-arm-bushings)
My front springs are modified (https://www.bimmerforums.com/forum/showthread.php?2430780-PSA-Finally-a-fix-for-ride-height-that-doesn-t-hurt-the-ride) stock. Front spring pads are 31331135589 uppers (10mm with castellations, used on E32) and 31331124322 lowers. Front strut mounts are V3 and mine use an E9x upper spring perch 31336764093 that lowers the car ~7mm compared to stock E34 perch, cancelling out the 7mm gain from the upper pads over stock E34 3mm pads.
My rear strut mounts are custom, similar to the Moosehead design except bigger.
Had I the means, I'd've also bought genuine Touring-specific shocks, front and rear.

[Sir Montalbon]

Agree with moroza, it's a fair bit of work and money even when doing it yourself, but the rewards are so worth it.

I recently did every piece of rubber under my '94 calypso touring (except the RTAB's and diff mount coming soon...) This included:
-tires
-all struts (took a chance on Monroe OESpectrum, cheap, lifetime warranty, and surprisingly nice ride on my daily interstate commuter)
-motor and trans mounts
-ball joints
-UCA's, LCA's
-exhaust hangers
-upper and lower strut rubber and tops
-subframe beer cans

Pretty much everything front and back, I'm sure I'm leaving some stuff out.

If you order everything from FCPEuro, you get a lifetime warranty. Even if the cost is a little more (not saying it will be, they are usually pretty competitive), it's worth the warranty alone.

It is pure bliss to drive now.

Do it.

[tymhm]

Thanks for the info from both of you! That's definitely the way to go, and I'll be saving those lists for future reference.

I guess my question was more shock/strut related at this point though as that's the first area I want to throw some money. The car feels pretty good steering wise otherwise, but I'm sure I could refresh somethings in there shortly. I haven't had a good chance to look things over on a lift yet but hope to in the near future.

[m60power]

I agree with what others posted above; it's a good idea to go through and replace all the suspension related wear items at one time. It'll be costly but worth it. You're on the right track by going through the realoem diagrams for your car to make a list of all the ancillary parts related to doing the shocks and springs. For front and rear - Definitely replace things like strut mounts, upper and lower rubber spring pads, hardware/fasteners, dust boots, bump stops, etc., that go along with the whole strut assembly.

While you're doing the shocks and lowering springs - I would replace the front control arms, thrust arms, (bushings too), sway bar links, steering links (center link, tie rods, idler arm and bushing). On the rear end definitely replace the 'dogbone' links, and consider replacing the two main subframe bushings, and the four trailing arm bushings. Possibly differential mount bushings if they look worn/cracked upon inspection.

Also, buy quality parts. I cannot stress this enough. If you are unsure on the brand then order the part directly from BMW. This place - https://www.thebmwminipartstore.com/ - has reasonable prices.

Edit: Some thoughts on the steering box. Having done all suspension and steering links at one time on one of my cars, the only standout negative with the e34/e32 is the damn recirculating ball steering box. They just have too much play when not loaded up. Also, In my opinion, at high speeds (greater than 70mph) the steering feel on these cars is fantastic even with a 'worn' box. I've never owned a super low mileage e34/e32 but I wonder what a new steering box feels like? One of my e32's has a damn good steering box, very little play on center (but still really could be better) compared to all other e34s/e32s I've owned and driven. I wonder how close to 'new' feeling it actually is. I personally suspect that worn thrust arm bushings, specifically the shimmy that goes along with it, is the main contributor to prematurely wearing the steering boxes out.

[TiagE39]

Moroza's post really says it, basically everything on that list will need to be done. These cars don't like sitting, and the rubber bits - which might feel fine at first on a low miles car - start to go quickly. Doubly so when you do struts first, they put more load on the bushing and balljoints which are already dried out from age I imagine.

That said, a minimum list might look like (if we're just talking suspension parts):

- Front Thrust Arms
- Front Track/Control Arms
- Rear "Pitman Arms" aka Dogbones
- Rear Subframe Bushings (even if these are in good shape now, they will fail shortly)
- F&R struts, but with all new mounts & hardware

Assuming your steering linkage isn't bad and your box is OK, this should get you a fairly tight car. As other noted, stick to OE Quality parts: Lemforder, MeyleHD, or Genuine BMW. I use TRW for certain suspension parts when available, and have been happy with them on my E39, but I would avoid any of the "generic" or compatible brands. Would also recommend FCP Euro, if not for the lifetime warranty then for their excellent customer service and shipping.

[moroza]

My take on part brands and manufacturers:

Don't get anything made in mainland China, full stop. Quality control is inconsistent (as opposed to hardware made in India, where it's consistently bad), and every dollar sent there is a vote for their environmental standards, labor conditions, and government. Regarding the latter, there've been increasing reports the last few years of outright prison labor, much of it through a "re-education program" tied specifically to auto parts makers.

Parts relying on rubber - bushings - should be Lemförder or genuine BMW only. Other parts, including balljoints (swaybar links, tierods...) can be alternative brands. My reasoning is that rubber parts are harder to make just right than metal; in a tierod for example, there's not much wiggle room (pun intended) between good and bad - either there's slop or there isn't - but in a rubber bushing, the wrong durometer can pass inspection and still cause driving issues in service. This is especially true for fussy suspensions like ours. Furthermore, most of the non-rubber parts are easily replaced later in case they loosen up.

FCP indeed has excellent service, in addition to the warranty and generally good pricing to begin with. My one problem with them, apart from being far away, is that their catalog isn't as extensive as ECS or a few others, and they seem totally unable or unwilling to get anything special ordered, even by a manufacturer whose other products they carry.