Rear Upper & Lower "Wishbone" & Trailing Arm Brackets Replacement. 2008 R56 Cooper S
 

Hello Desk Jockeys,

Im gathering parts to change the 4 rear "wishbones" (they are rods really, some call them control arms), parts 8 and 9 below, and the respective 2 trailing arm brackets, part 7 below, in my 2008 r56. 143k miles on the car.

Ive done everything else suspension related but am still noticing some harshness from the rear end which I assume must be these worn out bushings in the wishbones.

http://realoem.com/bmw/diagrams/d/u/376.png

I noticed that Rock Auto sells adjustables from MEVOTECH (Part # CMK100003) http://www.rockauto.com/catalog/more...id=371&jpid=25 for less than the cost of non-adjustables from Lemforder from ECS Tuning (ES#: 2804836 Mfg#: 33326768726) http://www.ecstuning.com/ES2804836/

The car is stock ride right. I dont need adjustability but if its not too expensive, why not. Anyone ever use MEVOTECH parts?

Also, the trailing arm bracket call have self tapping bolts. Can the old bolts be reused? I assume so.

Thanks,

Lex

BTW RockAuto sells the control arms/wishbones for $43 each. LEMFORDER Part # 3573501
Rear Axle, Upper, Lower, Left and right

Rockauto also sells just the bushings For $5 each. LEMFORDER Part # 3469701.

Has anyone tried to press them in and out? That's cheap as ****.

How to install bushings in rear suspension of R56 Mini Copper S
 

Alright girls, I was able to acquire and install 8 new bushings into the 4 OEM control arm (sometimes referred to as "wishbone"), 2 bushings per arm, and the 2 larger trailing arm bushings into the 2 OEM trailing arm brackets (one bushing per trailing arm) and saved about $300-500 in parts.

CONTROL ARMS

The 8 wishbone bushings are available from ROCK AUTO shipped from Europe (LEMFORDER brand) but I could never get them to ship because they were terminally out of stock so I gave up and found that a company called FEBEST with a Florida office that sells bushings for BMW/MINI. Part # 33326768724 You can order on Amazon at:

$12 each delivered. New arms with bushings vary from $70-$120 each x 4.

The biggest problem for those of us who don't have a multi-ton press is that these bushings are so small that the typical bearing or bushing presses available at Advance Auto etc for rental wont work because the forcing screw is too large to pass through the bushings or for the U type presses, the cups are too big. I tried some regular old construction grade 3/8th inch long screws from Home Depot but as expected the threads were quickly destroyed. Too soft.

The second challenge is that the ends of the control arms are not "boxed". In other words, they are open on one side, so when you press or smash the bushing the control arm end wants to close like a sandwich.

Here is the OEM bushing and wishbone (with 143,000 miles on it). See how its "unboxed":

Attachment 146173

The easiest way to do this in the absence of a proper press is via the U-Bangy Methodology. A.K.A a small sledge hammer, a 22 and 24 mm (Stanley brand, in my case) socket or whatever socket you have that will fit around the periphery of the bushing but not contact the wishbone proper, a vice and a piece of metal tubing of 2 inches diameter cut to the height of the gap in the control arm and able to encircle the bushing and provide support to the unboxed end as you smash the old bushing out and the new one in.

I didn't have any metal tubing handy so I bough the shortest cheapest section of natural gas pipe I could find. But honestly it doesn't matter what it is as long as its strong enough to handle the impacts and surround the bushings...could be a wrench, or whatever. You may need a 2nd person to help hold things together as you smash.

Attachment 146174

Here is one of the new FEBEST bushings for the control arms next to an OEM bushing I punched out.

Attachment 146175

Place the 24 mm or 22 mm impact-grade socket on the bushings and start smashing. The pic below showed me using a pipe wrench which I had tied with wire around the control arm. That didn't stay in place. The pipe section worked better. See pic of that below.

Attachment 146176

Attachment 146177

Attachment 146178

I like the 24 mm to start because it was on the very perimeter of the bushing. However, the 24 mm wouldn't fit through the hole so I had to switch to a 22 mm when I got the bushing pushed passed the lip of the wishbone.

Here is the trimmed pipe section...yes it eventually deformed and I had to use a new section every few bushings and yes it popped out every few blows, but this worked fine for once every 140k miles!

Attachment 146179

Once you get the old one out, start the new one with a few taps and start bashing it in. The wishbone may deform a little, and if so just use the flat corner of the vice which is about as thick as the control arm gap is wide and "push the sandwich apart" by hammering on the back of the arm. This will spread the arm apart again. Sorry I don't have a pic of that simple process...

Attachment 146180

Here is the 22 mm pushed most way through as I got the old bushings out:

http://i649.photobucket.com/albums/u...psexs6jvhw.jpg

Here is the wishbone slightly deformed. No big deal ladies...steel reforms nicely.

Attachment 146181

I have welding equipment and I should have just welded a 4th side onto each end and boxed them in. Silly me.

Torque spec: 75 ft pounds for all 8 control arms bolts once you're tightened them back in place.

TRAILING ARM BUSHINGS

The trailing arm bushings (2 total) which are pressed into the trailing arm bracket, are also available from FEBEST part # 33306772666 on AMAZON:

$17 delivered. New brackets with new bushings are $55-60 I think.

The trailing arm brackets, as Mini calls them, are much more robust then the control arms. They aren't fully boxed but close to it. They resisted the process no problem. However the OEM and FEBEST bushings have a non-contiguous rubber lip which makes pushing the new part in and out a little tricky because the rubber wants to deform as you smack it. For the old bushing just trim the rubber off so you have a full metal surface to make contact with. Again the standard forcing screws are too big to fit through this bushing, so I resorted to a hammer and a cup I had from my bearing press kit. Not sure what size impact socket would work..maybe a 36mm...I can check when I get home if you remind me.

See the rubber lip:

Attachment 146182

Also note that the bushing center is tapered on the OUTSIDE end where the huge metal cup washer fits against it, and is flat on the inside end.

Attachment 146183

See the cup washer?:

Attachment 146184

Attachment 146185

Here is the bracket, the bushing and the new FEBEST bshing next t it:

Attachment 146186

The bolt holding the bracket to the ALUMINUM (SOFT METAL) TRAILING ARM is a 20mm bolt. I used a 13/16th...20mm isnt the most common size. It's 122 ft lbs when you torque the bushing back into place onto the trailing arm, BTW. Use a fracking torque wrench!!!!...or risk destroying the trailing arm threads and $400.

RESULT: I've driven the car 70 miles, and the harshness from the rear suspension is much improved. This after having installed new Koni FSD struts all around. So even though the 10 bushings looked fine...no evidence of cracked rubber, they were in fact worn.

If the pressed in bushings don't hold up I will let you know.

How have the febest held up?

The car hasn't accumulated more than maybe 5k miles but so far so good. It's not really enough miles to be able to speak with confidence. They seemed like good quality when i had them in hand.