Pics soon to come

I had to replace the two upper balljoints on my 03 e320 and the lower ball joint so i figured i would change all four.

the required tools are:

13mm socket (deep and shallow)
17mm socket (deep and shallow)

2 21mm sockets

set of torx sockets and bits

3 foot breaker bar
2 1/2 foot breaker bar

long rachet

short rachet

air tools (not necessary but highly reccomended)

mercedes benz ball joint press (no choice if you don't have it, don't do it!!)

screw type ball joint separator (same as above)

 

this is the press tool it is absolutely imperative you have this because the lower balljoints are pressed in and without it you'd need a shop press.

 

here's the ball joint separator, this one worked awesome!!!! It didn't damage a single boot and it got even the toughest ball joint out (warning though when a balljoint pops out it is violent almost like a gun shot!!)

 

Parts:

My upper joints were replaced under warranty due to some TCB the dealer didn't give me detail about so i got away with the bolted upper joints. Some of you may have riveted joints. I am not sure if you can drill the rivets out but the dealer claims you need to replace the entire control arm, so those of you who have rivets i am not sure what to tell you.

part no.

 

lower ball joints:





this gets press fitted into the steering knuckle which is why you need the press... I bought the press for 145 bucks from ebay, you could do it with a shop press but you still need the cups that come with the press and you have to take apart more links to get the steering knuckle completely out

 

Now onto the meat and potatoes: Before we start i'll just tell you that it wasn't too bad doing this and now the car feels waaaaay more responsive. I made two stupid mistakes that cost me time, but hindsight is 20/20, ill point out the mistakes in the procedure. It is tedious and you cannot make any mistakes so pay attention to detail or it'll take you a long time to do it. I started at 11am and got done at 7pm if i didn't make the two mistake i probably would have gotten it done before 5pm.

First turn on your emergency brake after parking the car in a good spot in yoyr garage.

Now pop the hood and open the windows all the way because you are going to be turning the SBC brakes on and off and cannot open the doors. if you forget anthing in the car that way you can just reach in and not open the door

turn the car off and hide the key!! don't touch it wait til the instrument cluster turns off after you step out of the door, it may take a few minutes

after the instrument cluster turns off while you're peaking at it from outside of the car, go ahead and unplug the SBC unit

 

next break the lugnuts loose and jack the car up on jackstands

Take the tires off and it should look something like this



Now just compress the caliper just enough take it off and hang it to the side with your mercedes benz ceritified coat hanger (sarcasm)

 

oh i forgot to mention that you need a 13mm socket to break the caliper bolts free!!! and leave the wheel straight

Now you should have the caliper out of the way. I didnt bother taking the rotors or the pads off cause the assembly hangs and it it'd be a pain in the nuts to get the brake bracket out so id suggest leaving it in there:

 

Actually i guess you can say i made three mistakes because i accidentally yanked out the brake pad wear sensors and will have to buy new ones tomorrow but no biggie, try to remember to pry it out of the brake pad

Next we have to get the wheel speed/abs sensor out so it does not stretch or ruin

It needs an allen wrench i'll post the size of the allen wrench later:



the bolt that is right by the wire is holding the sensor in, i just tapped it with a hammer and it broke loose, the bottom nut is holding the balljoint and the structure to the left is the torque strut which you do not need to touch.

Next you take off the protective plastic shield, the clip is such that you squeeze and pry up with a screwdriver and it pops off





The sensor is in there good even after you loosen the bolt cause theres adhesive and dust caked in, i just worked it with my hand, do not pry on it with a tool because it is fragile

 

then after you get the speed sensor out set it aside and now you can work on the steering/suspension

 

ok now the first step is to get the upper ball joint off so you can just let the steering knuckle flop down and then you will have access to the strut and the lower ball joint. The steering knuckle will hang on the tie rod and torque strut arm after the lower ball joint is free. If you want, put a jack under them to support it and not put all the stress on the joints... i just let it flop. Ok so to take off the upper ball joints you can either take the one nut on the joint off and pop it out, or you loosen the three bolts on the control arm. Either way you have to do both. I decided to loosen the bolts then pop the link out. First loosen the nut on the link with a 17mm socket. The bolts on the control arm are torx on one end and hex nuts on the other. Use a 13mm hex socket and a torx. it'll be a tight fit for one of the torx heads on the bottom, just use a u-joint

 

after you' ve loosened all the bolts the steering knuckle will flop down and reveal the parts







this is the bolt that holds the strut to the control arm



the nut holds the lower ball joint which is connected to the control arm


Next we need to remove the coil over strut. To do this we need to remove three nuts on top in the wheel well which is in the engine compartment, then we need to remove the bolt that holds the weight of the car. The top nuts are 13mm and the bottom bolt is 21mm. The bottom bolt is held on by a self locking nut on one side so you need a shallow socket 21mm to wedge a breaker bar and let it hang to the ground to hold the nut while you loosen the bolt. I started with an air gun to loosen without the breaker then once i started spinning then i put the breaker in. The air gun made quick work of it, if i didnt have it would've taken me forever to break it free!!!

 

The large bolt will need some coersion to come out, use an extension and a hammer to bang it out. Now you should be able the finagle it out by pulling the bottom part towards the balljoint and it will slip right over the balljoint and out

 

Next separate the upper joint link. The ball joint separator i got was awesome it didn't harm the boots at all like a pickle fork would and you can fit it in a tight spot unlike the jaws. you slide it under the boot as far as you can and then tighten it. I had to use a 24mm socket on a breaker bar and when it let go.... it let go!!! Be careful it sounds like a gunshot.

 

ok here's where i made my first major mistake. I had to get the lower balljoint apart but here you have to pay attention to details. What i did was loosen the nut alittle then press it out, but then the whole joint/nut kept spinning and there was no way to keep it still and it was tight!!! So i had to use a sawzall to get it off . First get the nut off. I used a airgun and it made short work of the other side. THEN i pressed it off. Then i jacked up the assembly so it didn't damage the tie rod end.







In this pic i had made the mistake of not taking the nut off... make sure it is comletely off!!!!!!

 

Next it's time to press the ball joint out of the steering knuckle.

The press comes with four cups. Two puck shaped and two cylinder shaped

The small puck will push the ball joint through and the large cylinder will let the joint go straight up because it is wider than the joint. When it comes time to press the joint in you take a smaller cylinder which hits the flange on the ball joint and a bigger puck which does not allow the end that pushed out the ball joint to go through the hole any more. You need to use the 3 foot breaker bar because it takes alot of initial tension to get it moving and once it gets moving it is easier



small puck vs big puck



hard to see, but the big cone or cylinder sits on top while the small puck drives the ball joint through





bottom of the ball joint



after pressing it out



the old joint

 

Then to press the new one in you take the smaller cone and the bigger puck and press it in... This takes the 3 foot breaker bar again!!! You NEED to make sure that the ball joint is pressed FLUSH with the steering knuckled surface or you will throw off the alignment. You can tell because it gets hard to almost impossible to turn it and do a visual inspection to make sure there is no gap



Ok now install.

First you get the lower ball joint link into the control arm and hand tighten the nut on... This is where i tihnk i made my first mistake. I decided to leave the nut loose and was going to assemble everything and then do the final tightening last but tightening it now i think would've made more sense cause there would have been less parts in the way. Either way to tighten the nut you must raise the steering knuckle with the jack and put all the weight of the car on it and then tighten it so it doesnt rotate as you try to tighten, otherwise you'll be tightening all day long and get nowhere quick



I used the german method to tighten it, the goodentite method, i tightened it like i was tightening lug nuts, the only problem was that because i waited until everytthing was installed i had little to no room to move the breaker bar so i had to turn the wheel everytime, but in order to do that i had to put the key in, and that would activate the SBC so i had to put the calipers on and then put the key in then turn it off, then take the calipers back off so i had room for the breaker bar, don't make that mistake lol. Once it was tightened, next was to install the coilover strut.

To install the Strut is straight forward. It is just opposite of the removal. Only thing to know is that you have to pry the suspension down a bit to get the bolt to mate into the hole, then tighten it down with the goodentite method and blast it with the airgun again >

Then tighten the top three nuts

Next install the protective cover back on the steering knuckle for the speed sensor

next install the speed sensor back

Now you're ready to install the upper balljoints. Take the link and put it into the hole and thread the nut. Again the goodentite method

Next align the holes into the upper control arm and tighten using the u joint and 13mm socket and use the goodentie method

Now install the caliper back on

Install the wheel back on

Repeat for the other side


When done with both sides shake the steering knuckle and pry around to see if there is any play... there was absolutely none

Then lower the car off the jacks and drive

if you notice any omissions or errors let me know i am hungry and tired and about to zonk out. I hope this helps you DIY mechnanics out there. I spent a total of $400 and the dealer wanted well over 1500 for it probably because it is labor intensive. It is possible but do not make the mistakes i made and you will probably do it faster than i did

 

Great write up

I just found out today that my passenger/front lower ball joint is toast when we were installing my AMG brakes. It made my little winter project even more expensive

Thankfully we had a replacement on hand.

 

Great great writeup. Unless you are a heavy DIY'er, I would let a independent shop do this type of work. At least the parts and labor would be less than the MB dealer. You really need the specialized tools to do this.
Mike T.

 

thanks guys, when I found out i needed new upper and lower ball joints I had also needed new springs and struts because i saw my spring collapsed in the wheel well. The dealer wanted something to the tune of 3k to do the struts and the joints. I took it to another shop and they did the struts for 1400 and they wanted similar for the joints. So I did the joints for 400 and i saved 1200. If i had done the struts myself i probably would have only spent about 700 but hindsight is 20/20 and springs are one thing I leave to the pros. Better their head get chopped off than mine if the spring decompresses

 

oh yeah and thank god for air tools!!!!!!!!!