E36 (325i) Suspension Questions

Shift518 Automotive
1

Soon it will be time to do something about the floaty feel of neglected suspension parts.

Planning to replace the following with some parts from a couple of M3s:

Front
Lower Control Arms ('95 M3)
Sway Bar & Links ('95 M3)
Struts & Upper Mounts ('95 M3)

Rear
Rear Shocks ('99 M3)
Rear Springs ('95 M3)
Sway Bar ('95 M3)

According to the below:

http://www.understeer.com/lcab.shtml

  • '95 M3 bushings offset CA location for additional caster (and high speed stability at the expense of low speed turning effort, is my understanding).

  • '95 M3 bushings are pretty sturdy

Now, the bushings in the lollipop bracket portion of the fronts do seem good, so I am inclined to leave these untouched (despite a lot of advice to the contrary I know).

But if I’m going to upgrade, then I may as well do bushings in the rear suspension as well right?

I’m thinking to buy the rear trailing arm (RTA) bushings:

http://www.turnermotorsport.com/image/suspension/susp_e36_rear_carm_bush.jpg

Will getting the Upper/Lower RTA Ball Joint really do much? I was just thinking bushings but happened across this as well:

http://www.turnermotorsport.com/image/suspension/susp_m3_reartrailing_bush_lg.jpg

Do I need to do the upper and lower control arm on the rear suspension as well, where these mate to the subframe? See below

http://www.turnermotorsport.com/image/suspension/e36bushingupg_diag_v2_lg.gif

Questions & Stuff:

To reduce downtime, I was thinking to try and get a RTA as well as upper/lower control arms from another car and have new bushings put in along with ball joints then replace as a whole.

Is this a good approach? Can I use rear suspension components from any E36 (M or non-M?)

What’s labor cost on this? I don’t have access to a press.

Any recommendations for bushings? Powerflex?

Any suggestions on what do with in the front aside from possibly replacing the LCA bushing with a new one?

This is a daily driven car that I would just like to feel more planted and tighten things up. That’s all I need. Trying to avoid expenditure and a big science project, so I’m staying low budget where I can.

All advice is appreciated. Thanks.

2

Oh hi.

Ok so, couple things.

Firstly, Pete informed me the front struts, although they don’t look to be leaking or anything, are tired.

Secondly I really got down and looked closely at the lcab, and they do seem to be cracking ever so slightly. So I would suggest replacing them, we’ll adjust the price accordingly, having extra lollipops at least helps speed up the process as it’s just a swap at that point, very little downtime.

The rear trailing arm bushings are more than likely shot. poly squeaks. no matter what. it will. I suggest using the updated rtab and one of the various ‘limiter kits’ on the market, this stiffens up the stock bushing, adds life, and doesn’t squeak.

Chances are you do need subframe bushings, to minimize downtime I can sell you the subframe out of my parts car, have new bushings pressed in, and swap it. Pretty easy job aside from pressing the bushings, rear end has to come out to do it though, which isn’t bad at all, but then you’d probably want to do the diff mount bushings as well.

Finally the rear balljoints, again I have new upper and lower arms for you, which you can have replaced depending on which ones need it, mine are still solid it seems after almost 140k hard miles, if yours are bad I dont think the ones on the part car are bad at all.

Pending all of that you’ll have a VERY solid DD suspension wise. Don’t forget the driveshaft guibo and center bearing though!

3

Luckily everything you listed is relatively cheap and anyone can do the labor, except for the press part. If you remove the arms, any shop or even Midas can press the different bushings into place.

If you’re going to use the E36 M3 front sway bar, you need to use the E36 M3 front struts you listed too. The mounting point for the M3 is on the strut/shock body while on the regular E36 it’s on the control arm.

The M3 (non-webbed) offset front LCABs are worth doing.

All the front ball joints and control arm bushings make a big difference. The rear can make an equally huge difference, but it just takes the 7-10 bushings you listed per side instead of the 3-4 in the front. Luckily they’re cheap.

The RTAB is the only one that’s a PITA to do because if it’s bolted back up in the car improperly, it’ll have preload and tear itself when loaded hard. This is definitely the most important bushing in the rear - do it right. If you dont want to worry about the preload procedure, just get the Powerflex bushing. The dowel through the center can actually rotate, so it cant have any preload. The problem is the bushing is urethane and can only really dampen one axis of motion while the stock rubber bushing works in 2. For stock-ish height cars, this can be an issue if you’re at the last 10% of handling characteristics (baller shocks, serious car). Otherwise, dont worry about it and save yourself a huge hassle.

Also, every Powerflex bushing I can think of doesnt take a press to install. You can do them yourself.

Yes this is a good approach. It’s not real expensive and they car will drive like new when it’s done.

Re: what parts for what car - If you havent been here yet, go now: www.realoem.com

Changing certain things will affect others in the suspension like the M3 sway bar w/ M3 strut body, but just post if you have questions.

I have P-flex offset LCABs coming off my race car if you want them. My new headers are too close and are going to destroy the bushing so I’m replacing with a smaller delrin one. I’ll let em go cheap. Let me make sure they are in good shape first. They were used for maybe 1.5 seasons? Maybe 4000-6000 hard miles?

4

After reading Benny’s post - I have no idea about the NVH of any of the bushings I suggested. My car isnt exactly Lexus quiet and sophisticated anymore. I never noticed any squeaks from anything urethane when it was a street car tho. I always kept everything properly lubed up.

5

Archie if you need legit BMW parts my brother works @ keeler BMW in the parts dept. :wink:

6

:excited Whaaaaatttt? Who’s your bro? I am Keeler BMW/Mini Parts OG!

7

You can have that title… Shall I claim BF.com OG because I joined in my pre-pubescent years holding my 1/18 scale Burago M3?

Seriously, thanks for the advice. I’ll do the front LCA bushings for certain and am heavily considering an all out assault with Powerflex (as soon as I jack a Stewart’s to pay for all this).

So the P-flex bushings don’t press fit and expand outwards against the assembly / carrier when assembled?

NVH doesn’t matter much to me, so let me know about the condition of your offset LCABs.

8

Thanks for looking into the parts again man. OK, let me map out what I’m going to do here so I can get the right parts off of you based on the advice I received here. Considering your offer on the subframe and the rear arms.

I’ll text you or PM you offline to talk about pricing etc after I figure out what I’ll do exactly.

9

I’ll have the LCABs off sometime this week.

The P-flex bushings are often 2 pieces w/ a center dowel so, for the RTAB, they’d sandwich the ring the bushing sits into. For the front LCABs, the bushing is one piece, but it can be put in using common garage tools. I actually think I jumped on them w/ one foot to get them in - very scientific.

I’ve been happy with everything Powerflex I’ve had and in most cases they’re stuff isnt much more expensive than OEM if at all.