Possible to Remove W124 Lower Control Arm Without Spring Compressor?
 

I have done a search and found many threads detailing a method of raising the vehicle, then using a jack to support the control arm to allow replacement of struts and mounts, etc. without requiring a spring compressor. Can this method be used to lower the control arm enough that the spring can be removed without a compressor?

Only if you want to be killed!

Steve

Think of the weight of your car. Then imagine the front of the car takes up about 70% of that weight. Then think of 35% of that weight compressing that spring.

Then imagine a big metal spring flying into your body with the force of a pallet of bricks.

I expected a more macabre scenario from one whose moniker bills him as the bird of death!

In all seriousness, I am fully aware of what the spring will do to the human body. I almost lost a finger replacing struts on a Dodge minivan when the Pep Boys spring compressor gave way. You're not talking to a newbie here. A simple yes or no answer would suffice.

I know the rear springs can definitely be removed WITHOUT a spring compressor using a gradual lowering of the subframe until everything is low enough that the springs just fall out quietly. You have to do both sides rather than just one, but it is definitely possible and is also safe. I had imagined that perhaps the front lower control arm could also be gradually lowered to the point where the spring is no longer compressed. Can anyone point out whether or not this is possible?

Instead of the spring flying into your body, imagine it taking off your nose on the way by...

I agree that the rears can be done safely without the proper tool, but would not touch the fronts without it. Did a set once with threaded rod/hooks tool, took forever and had to reposition/do over so that the compressed spring could actually be removed from its location. Have also done a R107 by removing the control arm bolts and pivoting about the ball joint using a floor jack. I backed away from it more than once (ball joint allowed movement in more than one axis). I have a friend who lets me use his proper MB tool, have never looked back and would not attempt the job without it.

This is exactly how I do it on my W210 car (shock + spring, not struts). I purchased the spring compressor and it can't successfully be used on the rear with the springs I've got.

I don't know how similar the W124 rear suspension design is. Obviously, extreme caution and gradual lowering of the control arm are essential.

I have never done this on a 124, in fact I'm not sure if I have ever done it on any MB. But I have used this method on many US model cars with the same suspension arrangment. Sometimes it's easy, somtimes its hard and requires a little help from a cheep external spring compressor and pry bars, sometimes it becomes absolutly scarry.

I recall a time where one of my co workers was installing the front springs on a 330 Ferrari. We had a guy Gusseppi, very familiar with these cars right from Italy watching what he was doing. He dident speak much English but between his hand motions and broken English he could usually get his point across. He walks up to this guy and says "My friend" then he points at what he was doing on the Ferrari, cupped his hands over his jewels and said "And thena I will a havea to go witha your girlfriend tonight".

Then he ran back into the machine shop whipod some tool up in about 10 minuts and installed the spring like it was nothing.

John Roncallo

I've done both fronts and the rears on several 124s. Never used compressor on rear, but keep in mind the rears will come more or less straight down. The fronts can obviously turn more and I think it would be much harder to get them to come straight down in a controlled manner.

So yes it can be done, but I would not do it without a proper compressor and I would not tell anyone to try to do the fronts without compressors. I think it's to dangerous to do without compressor.

I think it would be nearly impossible to get the spring back in without a compressor. Although, someone will probably chime in and say they have done it.

I've done mine. GET a spring compressor!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! it can not happen without on that car.

Yes

I've done it on a 201 -- which is the same set-up but dementionally smaller.

HERE'S THE MOST IMPORTANT STEP: I created a "safety chain" by running a loop of chain through the spring and around the control arm, so that even if the spring did let go, it was secure.

I kept the control arm attached to the body of the car, and with the jack under the ball joint, I slowly/carefully lowered the jack... allowing the control arm to pivot.

The safety chain never came into play in my case -- both my springs went off and on without incident. But to perform this proceedure without it would be profoundly dangerous -- and stupid. (in my humble opinion)

jp

I've seen the safety chain only method, (scary) and in fact, we used the chain/cable even with the spring compressor on one of the jobs we did back on the farm on a truck. I would never do this without a spring compressor. They are easy to get and fingers and such aren't.

I've been reading the W124 ball joint DIY: http://www.peachparts.com/Wikka/W124BallJoint

Look at this picture:

http://www.peachparts.com/diy/w124ba...s/image034.jpg http://i35.photobucket.com/albums/d1...w124spring.jpg

It looks like you could take a weightlifting bar and run it through the bottom hole in the LCA, through the spring, and out the top of the spring perch, leaving it sticking out about half a foot. Then you could lower the LCA very slowly until the tension on the spring is released. I would think a weightlifting bar or something similar like a thick rebar is much stronger than a chain and not going to get snapped in the event the spring dislodges.

i agree it can be done but what are you trying to do? my shop is not that far from you and i have the benz spring compressor.call me,sat morns are usually free.

David, a most generous offer! I'll be in line when you move to the mid-Atlantic coast:)

Thanks for the offer David, I may take you up on it just yet. But I found this thread last night:

http://www.peachparts.com/shopforum/diesel-discussion/84056-front-spring-removal-i-thought-simple-without-special-compressor.html

Somehow I overlooked this thread in my previous searches. It looks like my idea can work after all and isn't exceedingly dangerous, as a few individuals have already done it before with no problem. I think I will use the free hook compressors from Autozone as a safety, but it would appear that the spring only has 3 or 4 inches of travel beyond the fully-extended position with the LCA hanging prior to disconnecting the strut, so at that point it is almost fully unloaded.

I am attempting to repair THIS. I will give it a try in a couple of weeks and will attempt to document with pics and a writeup. If I have to resort to a spring compressor you will hear from me.

i had a front spring break on my 87 300d, so it was not possible to use the mb spring compressor. the spring is like a locomotive spring, so i just brought it into shop and let them mess with it.

they had a few guys push up on control arm and remove bolts and lower the arm. This worked fine. What surprised me was they installed the new spring same way - had a few guys push up on the control arm to get bolts back in place.

So...it is possible and it was done on my car.

Would I have been the one doing the work? HELL no, and there isnt much I'll let a shop do for me.

SUCCESS! Well I just removed the control arm successfully WITHOUT a spring compressor. It was so easy I'm actually quite amazed. I don't think doing so was dangerous at all. Here's what I did:

01. Set parking brake and chock rear wheels.
02. Jack car very high up at center of crossmember.
03. Place 2 jack stands at frame near jack points.
04. Remove wheel, caliper, and sway bar with impact wrench.
05. Separate steering knuckle from outer tie rod.
06. Remove jack, place under control arm, jack up slightly.
07. Remove ball joint pinch bolt with impact wrench.
08. SLOWLY lower control arm, then remove spring.
09. Remove eccentric control arm bolts, then remove control arm.

Note in step 8, as long as you lower very slowly, there really is no need for a spring compressor. I rented the loaners from AutoZone to be safe, however the jaws were too big to fit between the coils so it turned out I couldn't use them anyway. Just for safety I ran a ratty old 20 amp extension cord through the spring as indicated by the yellow line in my previous picture above, but it never came into play and I don't see how it would since the control arm's geometry will not allow it to let go of the spring until the spring is almost fully extended. Once the ball joint pinch bolt is undone, the control arm just needs to drop somewhere between 45 and 90 degrees and you are home free.

At the end of the control arm travel, it appeared the arm was "springing" back up, making separation of the ball joint and subsequent removal of the spring a little precarious. Upon observation, it appears this was a function of the rubber bushings acting counter to the eccentric bolts; in the future I believe loosening the bolts enough to clear the eccentric will reduce or eliminate this springy feeling, allowing the control arm to drop all the way to 90 degrees more easily.

It does look like reinstalling the spring is going to be a royal pain, only because it is going to want to pop back out. But I'm sure I can get it to catch just a quarter inch of the control arm indentation, which is all that is needed to be able to raise the arm and compress the spring once again.

In summary, it is my opinion that a spring compressor is more of a convenience for this job. I could see where it could be essential for other jobs, such as when you wish to remove the spring without disturbing the ball joint and/or tie rod, etc. but for my purposes it was perfectly safe to remove the spring without one.

Oh yeah, it took me about 1:45 to do this job, and 45 minutes of that was easily spent on separating the tie rod end. I actually damaged it in the process since it appears to have been overtorqued by me. I replaced the tie rod end when I first bought the car, and in my haste I recall guesstimating the torque - I admit, one of the few occasions I have ever done so. I had to use a torch, bent a tie rod puller, and couldn't even get it separated with a pickle fork. In the end, I used a large gear puller and it popped just before I thought the puller was going to break...

CAN it be done?--YES. Should it? You like living with all your fingers, eyes, etc? Why take such life threatening chances trying to save a very few dollars. Life is precious, not cheap. Check out emergency room visit costs first. Simple cuts are $1000+

You don't get it, do you? Some people said doing this job without a spring compressor was dangerous. But others reported just the opposite (see posts 12 and 18 above). So I set out to learn the answer, and was successful. It has nothing to do with money. Your overdramatization of "life threatening" is just plain silly. As I mentioned, the spring is already almost fully extended with the car up in the air, and only extends another 3 or 4 inches by lowering the control arm past its normal limits. If I took video, you would be shocked to see that the arm drops and the spring just slips out of the perch with very little force. You may need a prybar to get it past the quarter-inch indentation on the control arm, but there is no life threatening danger at all.

This forum is about learning. I'm merely passing information on in the hopes that someone will benefit from this thread. If they read it and decide they want to use a spring compressor anyway, that's their option.

By the way, I positioned the jack in such a way that I controlled it from the other side of the car and was never fully exposed to the spring. If the spring were to fly out, it would have flown the other direction, away from me. This is a good practice but once again I report that the tension on the spring was almost fully released when it came out.

Bottom line: respect the spring
 

It stores a lot of energy and can maim or kill. Release the energy slowly, and stand on the opposite side, if you don't use a spring compressor.

It's important to remember, though, that the best laid plans of mice and men gang oft agly. 9 times out of 10 you don't need jackstands either, but applying Murphy's principle, you can be sure that just when you're overconfident that the car gods are always with you, the car will fall off the jack or the jack will fail.

A pic of the work in progress:

http://i35.photobucket.com/albums/d1...t/DSCF0029.jpg

New LCA arrived today, and I installed it after work. Took me just an hour. Put the LCA bolts in loose, then stuck the spring in place, just catching the lip of the indentation in the LCA. Slowly jacked up the LCA, compressing the spring, and *SNAP* the spring fell into place in the LCA indentation, about 1/4 of the way up. The rest was fairly straightforward, with a bit of wrestling with the ball joint to get it to slip into the strut assembly. Compared to the old one, man that new ball joint is tight! In the process I damaged threads on the pinch bolt for the ball joint. I managed to get it on anyway but will order a new one from the dealer for safety's sake. In the meantime, I'm waiting on the new tie rods - once they arrive and are installed, my car should be ready for alignment!

I like the fact that I get new ball joint and LCA bushings with a new LCA. For $89 shipped, I'm tempted to do the other side before sending it in for an alignment. But maybe I should leave well enough alone.

I stand by my initial assessment - removal and installation of the LCA without a spring compressor is definitely possible, and is safe if you take your time and pretend that the spring can come out any second and kill you. If you use extra caution you should be fine.

Hi David:

I'll be calling you this morning, I hope you are still doing work.

I have a 99C230K and I need to insrtall Koni Sport Kit (I already have it).

Okay does anyone know where to rent/buy the correct compressor in Dallas area?

I am going to do this on a W202.

Thanks.