Suspension and Rubber/Mount Replacement on Stock E36 M3

[zardano]

Heyo,

I have a stock 97 M3 in bad need of new suspension and chassis mounts. This car is solely used as a street car although driven hard as any M3 should.

I've used UUC engine and transmission mounts in the past and am leaning towards their "street" grade chassis bushings, but wondering if I should just go with OEM for anything they don't make, or Powerflex, or what people here would recommend. What brands are OEM? Is there a list of all the rubber parts that typically need replacement after 20+ years? Is the Meyle HD Rear Shock Mount kit the best option?

Also wondering if stock springs and shocks are good or if Koni or Bilsteins would be a better choice. Looking for good performance but with decent cushioning as well since the roads here are pretty rough and full of potholes.

Thanks for any advice/experience you can impart.

[TostitoBandito]

Lemforder is OEM for just about any bushing or ball joint in the suspension. For the rear shock mounts, buy Ground Control or Rogue or another similar aftermarket design that has fixed studs on a plate which drops in from the top. There's a number of threads around, including mine where I just did something similar, which detail the specifics. You can find all the part numbers and diagrams on realOEM, but in general you have (from front to back):

2x Motor Mount
2x Front Control Arm Inner Ball Joint - or buy new control arms
2x Front Control Arm Outer Ball Joint - or buy new control arms
2x Front Control Arm Bushings (FCAB)
2x Transmission Mount
1x Drive Shaft Flex Disc (Guibo)
2x Rear Trailing Arm Bushings (RTAB) - you should also get aftermarket drop-in limiters for these
4x Rear Subframe Bushings
3x Diff Bushings
4x Rear Outer Control Arm Ball Joints
2x Inner Upper Control Arm Bushing
2x Inner Lower Control Arm Bushing (if using stock lower control arms and not adjustable aftermarket)

That's pretty much all the wear items in the suspension there. Make sure and replace all the one-time-use locking nuts and whatever other hardware you care to at the same time.

For a street car the stock suspension is honestly fine, just get new shocks if necessary. If you want to spring for a coilover kit so you can lower it, have camber plates, or have a stiffer ride, there's lots of options there too. Bilstein is good, and Ground Control makes good Koni-based kits. Many of these kits will come with rear shock mounts, so keep that in mind.

[zardano]

Thanks for the list. I'm excited to replace all of this and feel how this car handles with fresh rubber.

I don't want lowering springs or coilovers or a stiffer ride, so likely sticking with a stock setup. I think I was reading somewhere on here that Koni shocks with the stock springs were a nice option over OEM Sachs...Anyone have any opinions/experience with this?

[realjones]

The koni shocks are great, but they are inserts in the front so a bit of a pain to install. I switched back to Sachs when they wore out and honestly can't say I noticed a difference (street car). Make sure to replace the strut mounts and sway bar links too. I've used Meyle HD, Febi, etc....no issues no need to pay twice the price for lemforder if you don't feel it's worth it (looking at you control arms).

If your springs are original I'd consider replacing them. I skipped mine the first time and the front ones actually broke a couple years later. The Dinan ones are barely any drop and not too expensive.

The above list is obviously great, but you don't have to do every little diff and control arm bushing to feel a difference. Shocks, springs, and mounts are a great start.

[zardano]

Cool, thanks. Having trouble finding the stock springs. Do you happen to know the part numbers? Realoem doesn't even have them listed for my car (says "No parts found matching your car." for both front and rear coil springs). ?? Most sites return no hits when searching for "coil spring" or just return the rubber spring seats. Autohausaz does have the Dinan kit for $256 but nothing for stock. Are they a dealer-only part?

[bluptgm3]

Running Dinan and Bilstein (M3) on sons 328.
1995 M3 H&R OE Sport springs (and 1995M3 ‘hats’ and upper spring pads) and Koni on Wife’s M3 Sedan.
LOL!!! Not sure which I like better. They both have similar (minimal) drop and rate.

Running Lemforder E46M3/Convertible Rear Shock Mounts on both.
Tried Meyle HD and they failed within 1K miles.

Running OE springs and Koni (Cut-n-Gut) on my 268K M3, with Turner alloy RSMs and they ‘squeaked’ forever.


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[realjones]

Cool, thanks. Having trouble finding the stock springs. Do you happen to know the part numbers? Realoem doesn't even have them listed for my car (says "No parts found matching your car." for both front and rear coil springs). ?? Most sites return no hits when searching for "coil spring" or just return the rubber spring seats. Autohausaz does have the Dinan kit for $256 but nothing for stock. Are they a dealer-only part?

Rear springs are 33539069133, but also very expensive. Front springs are I think 31332227836 (assuming the ones from 95 fit a 97). I went Dinan for the set as it is much cheaper. Autohausz shows no stock probably bc they are drop shipped directly from Dinan. If you want to order from them try calling. I bought mine from FCPEuro and they were shipped directly to me by Dinan.

[bluptgm3]

‘Hats’ and upper spring winding is different between 1995M3 and 1996+M3.
The H&R OE Sports are configured for the 1995M3 ‘hats’, they can be run on 1996+M3 by using the 1995M3 spring ‘hats’.

OE springs are not necessarily Dealer only, FCP, ECS, Pelican can/should be able to get them, but by special order. They won’t be cheap.


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[zardano]

Ah yeah, the stock springs are crazy expensive. Each rear spring costs more than the whole kit from Dinan. Now I just need to decide if it's worth it to replace 21 year old springs with the Dinan ones or just re-use the originals

[TostitoBandito]

If the original springs are intact and undamaged they're probably fine. There was nothing wrong with mine when I replaced them several years back on my M3. That said, if you're taking everything apart then it's pretty trivial to replace them with whatever aftermarket springs you desire, and springs aren't very expensive either (in general). Just don't get anything that differs in height from OEM, and don't get any linear/race spring with a fixed rate (unless that's what you want). You probably want progressive springs like OEM that are nice and squishy as they a first compressed, before stiffening up under heavy load.

[zardano]

So it looks like the front control arms are M3-specific (31122228461 and 31122228462). I can only find these as OE/BMW-branded parts for $250-350 each depending on the site. This is annoying because the regular E36 3-series control arms can be had for $70-90 for Meyle or Lemforder. They are definitely a different size/not compatible? I also haven't found much information on the inner and outer ball joints for these arms, and whether they are different for the M3 versions and the regular E36 3 series. And if I can find them, the ball joints will have to be pressed into the control arms, correct? That might be worth the hassel if the alternative is $500+ for both arms...

Also, the larger M3 subframe bushings are pricing out for at least $100 for the pair (33319066671) and are again apparently not supplied by any aftermarket manufacturers, BMW-branded only. Anyone know of a cheaper alternative? At that price for just two of the OE bushings the UUC urethane subframe mount kit for $160 seems like it might be a better option.

[bluptgm3]

All E30s, non-M E36 and 1995M3 have the same FLCA geometry, the 1996+M3 has it’s own FLCAs with different geometry.
Lemforder is OE supplier and the (only) OEM supplier for 1996+M3 FLCAs.
If you had a 328/323/318/325 or a 1995M3 you could run the Meyle HD FLCAs with solid outer ball joint.

The alternative for 1996+M3 is to press new E30 Ball Joints into those arms.

http://www.m3forum.net/m3forum/showthread.php?t=402063

https://www.bimmerforums.com/forum/s...E36-M3-spindle


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[TostitoBandito]

To save you the trouble of searching, if you want to press your own front control arm ball joints, here are the part numbers you want. Two of each.

31121126253
31121126254

They run around $15-16 each for Lemforder if I recall. $65 and an hour or so with a press (even if you have to buy a press for $150), is cheaper than new M3 control arms.

For the rear subframe, putting 95A poly in there won't add much in the way of NVH. I'd suggest this over OEM even on a street car. Just make sure and get poly bushings which have a metal inner sleeve and you're fine. Powerflex, Revshift, etc... If you also put 95A in the diff bushings you may get a little bit of diff noise from the rear end, but if you go for softer 80A for the diff mounts (or retain OEM rubber) that should minimize that. Or you could go soft on the subframe and stiff on the diff. It doesn't really matter since the diff bushings transfer into the subframe, which transfers to the car via the subframe bushings. So there's two sets of bushings between the diff and the car. As long as they're not both solid, the NVH won't be bad.

[bluptgm3]

Additionally, if you use poly bushings in rear subframe, you may find ‘dishing’ of the included captive washers. You can get slightly thicker washers from McMaster-Carr.


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[zardano]

This is all great information, thanks. Can I use poly bushings for anything else without adding NVH? FLCA or RTAB? Or just get the limiters for the rubber RTAB?

[TostitoBandito]

This is all great information, thanks. Can I use poly bushings for anything else without adding NVH? FLCA or RTAB? Or just get the limiters for the rubber RTAB?

Don't use poly RTAB's. Poly is bad there since it needs to move on two different axis. Use OEM rubber RTAB's plus the drop-in poly limiters which fill in some of the extra space. I bought my limiters from Vorshlag, but many aftermarket people make them and they aren't expensive. They're usually some type of dense polyethelyne or delrin or something which is durable and low friction.

For the FCAB's, I don't think my 95A poly adds any significant NVH there, but my suspension is already fairly stiff. The front control arms also connect to the chassis via the subframe (ball joint) so the bushing isn't the only point where NVH can be transferred to the car from the arm. That's why I don't think it makes a ton of difference in NVH unless you go to something like solid/delrin or a monoball bushing for a track car. That said, for a street car nothing is wrong with new rubber either.

As for the rear subframe bushing washers, I bought shiny new OEM washers when I did mine and they fit the Revshift bushings I got nicely. The bottoms of the poly are profiled to more or less match the washers (which have an indentation) and I was able to torque the bolts to spec without any issues with the washers deforming. Other bushings may vary though.

[realjones]

So it looks like the front control arms are M3-specific (31122228461 and 31122228462). I can only find these as OE/BMW-branded parts for $250-350 each depending on the site. This is annoying because the regular E36 3-series control arms can be had for $70-90 for Meyle or Lemforder. They are definitely a different size/not compatible?

They are compatible IF you change to offset FCABs to go with them. Meyle HD control arms with offset cabs fits just fine (changing to offset fcabs maintains the caster/suspension geometry). The 96+ M3 came with centered FCABs originally. Switch them out and you are good to go with the cheaper control arms. This is how my car is setup.

I've had the Meyle HD control arms with offset fcabs on my car for many years...bimmerworld used to sell a kit that came with everything. Like you I didn't want to deal with presses or spend $500 on control arms. Very common on track/autocross cars too tons of threads about it if you want to search.

[bluptgm3]

They are compatible IF you change to offset FCABs to go with them. Meyle HD control arms with offset cabs fits just fine (changing to offset fcabs maintains the caster/suspension geometry). The 96+ M3 came with centered FCABs originally. Switch them out and you are good to go with the cheaper control arms. This is how my car is setup.

I've had the Meyle HD control arms with offset fcabs on my car for many years...bimmerworld used to sell a kit that came with everything. Like you I didn't want to deal with presses or spend $500 on control arms. Very common on track/autocross cars too tons of threads about it if you want to search.

I don’t know why BMW changed FLCArms and FLCABushings if it was just that simple. They could have simply reused the the 1995M3 FLCA (318/325/323/328 and 1995M3 FLCA geometry is the same) and offset 1995M3 (and E30 M3) FLCABushing geometry. The BimmerWorld ‘kit’ probably kinda’ works when combined with Camber Plates to modify the missing 1996+M3 Camber.

I was not aware of the BimmerWorld 1996+M3 ‘kit’. They did promote the 1996+M3 Spindles/King Pins, and Meyle HD FLCAs (I was under the impression that these were for 1995M3, and 318/323/325/328 to replace the ‘floating’ outer ball joint.
My understanding is that they promoted the 1996+M3 Spindles/King Pins as they added camber at steering full lock. The 1996+M3 Guide Support/Strut Mount moved the top of the strut outboard to reduce straight line static camber. Static camber can be gained back by swapping the Guide Supports/Strut Mounts side-to-side.

I kinda believe there is a camber change and a caster change created by the 1996+M3 Forward Lower Control Arms, more than just caster created by 1995M3 offset FLCA Bushings.


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[realjones]

Is it exactly the same down to the tenth of a degree in camber/caster? I don't know, but I have no issues with alignment or the wheel being positioned any differently in the well. Theoretical vs. real world - certainly no difference in driveability over the last 20K miles.

The stock control arm was techincally never meant to have the balljoints replaced in it either...The bimmerworld kit was just control arms with a couple different pre-pressed fcab options.
http://store.nexternal.com/bimmerwor...kits-p879.aspx