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I'm trying to replace my control arm, but I'm stuck. The car is lifted on both sides, and I can't get the ball joint separator extractor to fit around the joint. I even cut away the rubber around the control arm to make more space, but it still won't fit. What should I do? I've been stuck on this for a long time.
this is on a 2010 C300. I ordered a larger ball joint separator as well but again I don't know if this it me messing up or what as all of the videos were using this ball joint seperator.
P.S. It's tough when you rely on your car for everything. I enjoy learning how to fix things, but it's stressful when you don't have other options
Last edited by Logan_Volcan; Jul 19, 2025 at 01:07 PM.
You can use a large pry bar (like a floor jack handle or large pipe) and a hammer to separate the joint. You want to have someone pry on the joint as hard as you can like your trying to pry it apart. Then you hit the metal part where the taper of the joint goes into. Hit it hard while prying and it will pop apart easily. Very much like this video but with prying.
Easily is a matter of opinion, even though this is a good suggestion. I haven’t done this in years. I actually used the separator plus striking on my old E Class.
To separate large tapered joints in my shop I keep a 5 pound lead block for back up mass behind the joint and use a 4 pound mall as a striker. Repeated hammering without using enough force to separate the joint can begin to deform the part.
Get out the angle grinder and trim down the top of that first puller. Thread a nut on the threaded end, even weld a second nut on to open up the puller more.
When I was doing the front brakes my 17mm wrench wouldnt fit the caliper bolts, got out the grinder and made it thinner to fit.
Okay I finally got it to be removed. Literally there is a german car specific bolt extract removal that fit it perfectly and removed it. This took me way too long to figure out!
Now this is what i have. I have no idea if I'm suppose to raise the suspension up and then put the arms back in and then tighten or put all of the arms in and then raise it and tighten it. So the wheel is completely off as you can see and it doesn't even make sense to me on what goes in first and then next step.
Also how do I raise the suspension to put the wheel back in spot? would a bottle jack work? that part makes no sense to me.
The joints can be tightened on the wheel side while still in the air. The bushings on the car side need to be tightened when the car is on the ground at ride height. This can be done at ride height, or when jacked put on the tire and then use a second jack to jack the wheel to the property distance from the hub to fender.
These also work well but there are definitely Mercedes specific tools needed for some of the joints due to clearance. I have a medium sized tool like on the top row and it does well to not touch the boots if they are not being replaced.
The joints can be tightened on the wheel side while still in the air. The bushings on the car side need to be tightened when the car is on the ground at ride height. This can be done at ride height, or when jacked put on the tire and then use a second jack to jack the wheel to the property distance from the hub to fender.
These also work well but there are definitely Mercedes specific tools needed for some of the joints due to clearance. I have a medium sized tool like on the top row and it does well to not touch the boots if they are not being replaced.
okay perfect. I have put everything back together. So do I know put the jack under the lower control arm to raise it?
I guess i shoulder lower the car on the under side and measure the distance to make sure this is the right distance.
This is one of the biggest parts that i'm worried about.
you can either crawl under when it’s on the ground or lift the wheel tho the right fender distance and then tighten. Sometimes it’s easier to crawl under at proper right height get them as tight as you can and then raise it back up and tighten to the proper torque. The goal is to tighten the bushing while it is “at rest “ so that it isn’t sitting under load with a twisted bushing. You only want that bushing to twist as the control arm moves down from static position or up from static position.
you can either crawl under when it’s on the ground or lift the wheel tho the right fender distance and then tighten. Sometimes it’s easier to crawl under at proper right height get them as tight as you can and then raise it back up and tighten to the proper torque. The goal is to tighten the bushing while it is “at rest “ so that it isn’t sitting under load with a twisted bushing. You only want that bushing to twist as the control arm moves down from static position or up from static position.
i wouldn't be able to fit under the car
but you are saying put the tire and everything back on and then lower it and then tighten the bolts? I didn't know i could do that. I guess maybe if the tire is turned to the side i can do one and then turn the tire to the other side and then do that side. would that be okay?
and wouldn't the tire and everything put a lot of pressure on it if i'm lower it on it. I guess as long as they are not tight you are saying it should be okay.
Put everything back together. The strut bolts can be torqued at this point, no where in the MB instructions say the car has to be in ready to drive condition.
The only things that I would torque with the car at ready to drive condition are the bolts in the control arm bushings.
Me, I torque all the suspension bolts with the car up on wood ramps I made. I can fit under the car with two 2x12's stacked on top of eachother. If im working on the car ill put the wheel on and lower the car down onto the ramps, crawl under, torque the bolts .
Put everything back together. The strut bolts can be torqued at this point, no where in the MB instructions say the car has to be in ready to drive condition.
The only things that I would torque with the car at ready to drive condition are the bolts in the control arm bushings.
Me, I torque all the suspension bolts with the car up on wood ramps I made. I can fit under the car with two 2x12's stacked on top of eachother. If im working on the car ill put the wheel on and lower the car down onto the ramps, crawl under, torque the bolts .
@TimC300 this is the only part i'm so lost about. And have so many dumb questions (sorry about that).
1) I can put the tires on and lower the car onto a ramp without messing up the bushing? I would need to turn my wheel straight, that wouldn't messed it up either? once the tire is on it then it naturally would go to the driving height i'm assuming....I don't know why no one had mentioned in all of the videos i had looked up before. And would a ramp that i purchase from a store be okay?
2) I don't have a ramp but can i use the extra jack that i have to lift it? (I attached pictures with the questions).
Last edited by Logan_Volcan; Jul 24, 2025 at 08:07 PM.
thank you. So just raise it until the wheel hub (I don't know what it's called) is 16" from the center to the lip of the rim and then i would tighten the bolts on the bushing.
I also went and bought one of these ramps just in case. But if the lifting does not work can i put the tire on it and lower it onto a ramp, would that be okay or would it still hurt the bushings?
it'll be funny if I lowered it onto a ramp but then i couldn't fit under the car.
^ That's what I do for front or rear axles. Ramps to get it just high enough that I can get under there. Whatever fastener is loose when you put the car down. Jump in the car and try to compress the springs while you're at it. Then snug her up.
Sorry I couldn’t respond earlier, but it looks like you are on the right track. Tightening with the proper hub to fender distance regardless of tire on or off.
for those not aware, bushings always have to be tightened to a drive position otherwise they are under tension at rest and will prematurely wear. You only want them under tension when the car is extending or contracting the suspension. Imagine if you tightened up the bushing while the wheel is completely drooped. That means when driving and the wheel goes up into the wheel arch it is going well beyond the designs torsion. On an alignment rack, car is at drive height and techs are working under the car..wheels are not lifter or drooping. Additionally, if you were to tighten the bushings differently on both sides, they’re not going to have equivalent, spring pressure or damping pressure..
Sorry I couldn’t respond earlier, but it looks like you are on the right track. Tightening with the proper hub to fender distance regardless of tire on or off.
for those not aware, bushings always have to be tightened to a drive position otherwise they are under tension at rest and will prematurely wear. You only want them under tension when the car is extending or contracting the suspension. Imagine if you tightened up the bushing while the wheel is completely drooped. That means when driving and the wheel goes up into the wheel arch it is going well beyond the designs torsion. On an alignment rack, car is at drive height and techs are working under the car..wheels are not lifter or drooping. Additionally, if you were to tighten the bushings differently on both sides, they’re not going to have equivalent, spring pressure or damping pressure..
Thank you for the explanation. I wasn’t aware of what caused the damage, so I appreciate the clarification. Just to confirm, the damage occurs when the car goes over bumps and the suspension moves beyond its intended range, putting extra stress on the bushings. Simply installing the tire or letting the car sit with weight on it would not immediately damage the bushings. Instead, incorrect tightening would cause the bushings to wear out much faster over time due to the added tension, but it wouldn’t tear them right away or within a few days. Is that correct
[QUOTE=Logan_Volcan;9192816]Thank you for the explanation. I wasn’t aware of what caused the damage, so I appreciate the clarification. Just to confirm, the damage occurs when the car goes over bumps and the suspension moves beyond its intended range, putting extra stress on the bushings. Simply installing the tire or letting the car sit with weight on it would not immediately damage the bushings. Instead, incorrect tightening would cause the bushings to wear out much faster over time due to the added tension, but it wouldn’t tear them right away or within a few days. Is that correct[/QUOTE
Correct. The bolt supports the weight intially. Its about not tightening it when it is not "clocked" correctly. This is only important on rotating bushings, not those that are compressed.
I'm trying to tighten some of these bolt and I couldn't get the torque wrench to click so I started testing it with normal wrench and I don't see the bolt tightening. Am I missing something?
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