Front rearward control arms (thrust/tension) ball joints

[Ramblin]

2009 BMW 328i xDrive
94k miles

I'm hoping to make a how-to guide and/or sticky out of this eventually. I searched and searched and haven't found a solution to my issue. Not in my Bentley manual, not on the forums, not on Pelican Parts, not on Bav Auto, not on YouTube. I'm stuck. What little I've found tells you how to remove only the control arms and it's for a non-xDrive model. Nothing about the ball joints. If anyone has a link to the right one, that'd be awesome.

This is the control arm I'm referring to: http://www.pelicanparts.com/catalog/images/Connect-Images/31126768983-M69.jpg
It bolts up to the rear of the knuckle (nut is on the bottom) and the arm faces rearward.

I'm getting the infamous "shudder under braking between 40-50 mph" that usually means control arms. So I'm replacing them. The forward control arms (smaller ones) have been no problem, other than the 24mm nut is extremely hard to get a wrench on.

I can get the rearward control arm out of the subframe with no issues. However, the arm won't come off the ball joint and the ball joint won't come out of the steering knuckle. Pelican Parts states that, "The ball joints on E90 models are not interference fit. You do not need a pickle fork to remove them." Mine must be seized and rusted in then because they're definitely interfering. Both bolts are out of the ball joint flange and the 24mm nut is off the other end. I've tried PB Blaster, tried yanking around on the arm, tried hitting it with a hammer, tried getting a screwdriver/prybar between the ball joint flange and knuckle (yellow arrow location), tried dang near everything.

These components aren't coming apart. Is there a special tool I'm missing? Do I need to try a torch? I don't have access to a lift so I just have the vehicle well supported on jack stands. Please, for the love of all that's holy, help me.

[Critter7r]

you may need to remove the CV shaft from the knuckle to get at it.

The proper tool likely attaches from the top, grabs the underside of the ball joint mounting area and presses downward on the joint to push it out.

Or, get a big hammer and smash it from the top after removing the CV shaft.

All BMW ball joints press together, and while I'm not completely certain what "interference fit" means, both the joint shaft and the hold in the arm are tapered and fit together.

[cochise325]

OK. You have two questions.

Separating the arm from the ball joint is one matter. If you use a fork, your risk damaging the ball joint boot. You can use a ball joint separator that is the press type (not fork). They are a common item and can be found at Harbor freight or www.ecstuning.com (http://www.ecstuning.com) if you want to mail order. The control arm has a taper fit to the ball joint, and while not meant to be an interference fit, the tapers come together so perfectly that the surfaces are tight together. Do not put heat on the joint, because inside the ball joint there is a plastic material that will melt (and so will the boot). This method allows you to use your existing ball joint, if they are in sound condition.

The second issue; removing the ball joint. They are pressed into the steering knuckle from below. I used an electric drill and drilled several holes down into the metal cap. This allows you to remove enough of the plastic (the socket portion of the ball and socket joint) that the ball portion can be lowered out. With the ball removed, I then used a hack saw blade to cut a grove into the outer portion of the metal hoop (being careful not to cut into the steering knuckle). Once the hoop strength is removed, you can tap the rest of the ball joint out of the steering knuckle. It takes some time and patience, but you will get her out.

- - - Updated - - -


you may need to remove the CV shaft from the knuckle to get at it.

The proper tool likely attaches from the top, grabs the underside of the ball joint mounting area and presses downward on the joint to push it out.

Or, get a big hammer and smash it from the top after removing the CV shaft.



All BMW ball joints press together, and while I'm not completely certain what "interference fit" means, both the joint shaft and the hold in the arm are tapered and fit together. Removal of the drive axle is a BIG deal, at the outboard steering knuckle.

[Ramblin]

Oh man, removing the CV shaft sounds way more involved than I want to get.

Saving the ball joints isn't an issue. At 94k miles, I figure they're either done or close to it. I'm planning to replace the 4 arms and 4 ball joints so destroying them is completely fine.

I like the idea of cutting with a hacksaw and drilling out the top. I thought of drilling out the top but hadn't followed through on that yet. Certainly wouldn't be an option for someone who wanted to save theirs.

[cochise325]

Are you replacing the front struts as well?

[Critter7r]

Removal of the drive axle is a BIG deal, at the outboard steering knuckle.

I have done halfshafts only on an E46, but it's really not a big deal. Remove the brake caliper, rotor, outer nut and tie rod and the knuckle swings away off of the splined shaft. I've done them 3 times on my E46. Takes me about 90 minutes from taking the tire off to putting the tire back on.

But if you can get a drill on the top of it to do it that way, go for it, that would save you the trouble.

[mikefromtoronto]

My shop had to hammer the crap out of it to get it off. I'd just keep at it with a big hammer. I doubt you will be able to do it without having the car on a lift.

[mikefromtoronto]

The bushings on my 06 E91 were pretty bad. No more shudder and the steering and ride is much smoother.

[mikefromtoronto]

Replacing both thrust arms was almost $350US

[Ramblin]

Well, I tried and failed. Not miserably, just regular failed. I bought some cutting wheels for my dremel tool and completely removed the top of one of the ball joints. It's a pressed on cap so after cutting an X, it fell into 4 pieces. I then put my pry bar on top of the ball and hammered away. Didn't budge. After struggling for a few days with multiple methods (and hammers), I finally gave up and took it to a local indy shop. They normally don't take outside parts but I guess they took pity on me. Cost me $337 out the door for 3.5 hours of labor and 7% shop fees. But DANG, this thing feels like a brand new car. Maybe I'm paranoid but I feel like I can still notice a slight shudder when braking. But I also have slotted rotors so that doesn't help. But the ride is so much smoother and it just feels incredibly more responsive.

Cochise- I'm not doing struts right now. They still feel ok but are likely something I'd replace in the next 10-15k miles.

So much for making a sticky out of this. I'm still really surprised that there aren't more pics/videos/advice floating around on the web for these.

[cochise325]

Unless you drill out some of the plastic around the ball itself, you can't get it out the bottom. But if you remove enough of the white plastic with your drill bit, then you can knock the ball out of the joint. Then you can use the hack saw blade to cut through the hoop.