W124 front shock replacement question - PeachParts Mercedes-Benz Forum

Jim's500E · #1 04-02-2003, 03:32 PM

I'm getting 2 stories...one saying the spring has to be compressed for the R&R of the front shock...other say no it don't need to be compressed (this on a W124.036). What are your opinions? Thanx.

Duke2.6 · #2 04-02-2003, 03:50 PM

To the best of my knowledge the 124 arrangement is the same at my 201. The strut is very easy to remove. Jack the front up and place jackstands UNDER THE CONTROL ARMS as far outboard as possible. With the weight on the control arms the springs will stay compressed from the weight of the car when you remove the strut, but you want the jackstands as far outboard as possible to maximize available leverage to keep the springs compressed beyond the rebound stop of the strut.

To remove the strut, remove the two bolts that hold the strut to the hub carrier and the nut on the top strut. You'll need a small metric allen wrench to hold the strut shaft, but a replacment bilstein shock I bought had a Torx center.

While the strut if off, remove the top strut mount and carefully inspect it for deterioration or cracking and replace as necessary. Recommend replacing the dust bellows apriori, as they are inexpensive and have a habit of disintegrating long before the shocks need replacment.

Duke

Jim's500E · #3 04-02-2003, 04:48 PM

Nice...Thanx man...I need to poop on my source who says the springs absolutely need to be compressed. I'm glad it goes easy like you say. Looks like it does and you're right about w124 and W201 being quite alike.

I got new upper shock mounts...my rubber ones are the original and looking beat at 136K...they were $40 each.

dakota · #4 04-02-2003, 08:44 PM

I don't know for certain one way or the other, but the MB manual (job 32-100) says to compress the front spring with spring compressor and tensioning plates. This may just be because it's easier this way and not necessarily because it's required, but I just thought I'd throw this in to the discussion.

Glen · #5 04-02-2003, 10:36 PM

Jim,
The springs don't necessarily need to come out, but be aware that the procedure described above is potentially very dangerous. I've done the procedure a bit differently, I supported the car with jack stands under the frame rails and then used a floor jack under the lower control arm. The jack enables one to carefully position the strut top back in the strut tower. I don't claim my procedure to be any safer, so procede at your own risk.

Good luck,
Glen

Duke2.6 · #6 04-02-2003, 11:33 PM

With the weight of the car resting on a jackstand under the control arm, not much short of the epicenter of a big earthquake is going to knock it off. If the jack supporting the control arm looses pressure or slides out you're going to be in deep yogurt. Jackstands don't have wheels!!! Jacks should only be used to lift a car. For any underneath work jackstands must be used, and I would NEVER,EVER rely on a jack to keep a spring compressed while I'm there doing any work.

Think about this for a minute and decide for yourself which procedure is safer.

One other suggestion. Jack the whole car up and support the rear at the rear rocker panel lift pads. It's best to have the car level rather than just having the front end up on stands under the control arm. The more nose up the car's attitude the less weight is on the front to keep the spring compressed as much as possible.

Duke

95E320cab · #7 04-02-2003, 11:39 PM

Today I learned how to replace my shocks and a new word. Thanks.

csnow · #8 04-03-2003, 11:15 AM

Despite what the FSM says, I feel Duke's method is safe, so long as common sense is applied.
Jackstands on level/hard/solid ground, and so forth.
Jackstands with a concave top {designed to receive an old-fashioned tube axle} fit perfectly to the arm here, while flat-topped one would not be as safe.
Just be very careful, and do not sue us.

sbourg · #9 04-03-2003, 11:39 AM

"With the weight of the car resting on a jackstand under the control arm, not much short of the epicenter of a big earthquake is going to knock it off. If the jack supporting the control arm looses pressure or slides out you're going to be in deep yogurt. Jackstands don't have wheels!!! Jacks should only be used to lift a car. For any underneath work jackstands must be used, and I would NEVER,EVER rely on a jack to keep a spring compressed while I'm there doing any work."

Duke, since you live in SoCal (as do I), we know that the "...short of..." happens a lot more than we like. This worries me when the car is up, and it is precisely because the jack has wheels that I rely on it as safety backup if a tremor hits. I use jack stand as primary support - the jack itself, wood blocks, free tires and wheels, whatever, as my safety backup.

Jackstands are only good if NOTHING shifts. If the car is intrinsically unstable on a jackstand, you may not know it until everything shifts suddenly due to a force vector that is not in-line with the jackstand axis of support. A mobile jack will tend to move withthe vehicle, or direct the vehicle motion in the free-motion direction of the jack, keeping it up.

I have never replaced struts on the Benz yet, and would judge about using compressors for stabilizing the springs before doing so. It seems like good insurance, though, and they are cheap to rent.

Steve

Jim's500E · #10 04-03-2003, 11:52 AM

Right on...either way will work fine I'm sure.

We used 2 jacks to do the rear springs, one for the car and one to raise and lower the lower arms...but the springs weren't as compressed as the fronts (didn't even need the compressor in fact)....it went pretty easy.

But I should use/get stands regardless...if nothing else so the fat slob can get off its SLS for the winter.

aldedmon · #11 04-03-2003, 12:37 PM

Jim you may as well go ahead and replace the upper strut mounts as well(relatively cheap anyway). They're probably worn near the end of their life anyway. You don't want to have to go through the same process in a few months to a year to replace these guys cause they're busted. I had to replace my upper strut mounts and discovered that one of my Koni's was busted. Sent both back and was rewarded with a brand new mathcing pair. Didn't wan't to replace just the leaking one and have a new one and a 4 year old one. Anyway just my .02 worth

md21722 · #12 04-03-2003, 02:24 PM

I've done it both ways. It was easier with the spring compressor than the floor jack because I could precisely control the angle of the control arm and this eliminated the need to compressed the strut to get the bolt holes to line up. Safer with the spring compressor too. Many have done it with a floor jack and lived to tell about it. I'd replace your strut mounts if they're original. They're very easy to change out with the struts removed - 3 bolts at 20 Nm.

Bzoo · #13 04-04-2003, 02:46 PM

Did the struts on my 92 400E putting the car on jack stands...let the wheel hang..took off the struts..put the new ones on...mounted the bottoms first so there was no issue lining up the screws and that was it.....15 minutes each side..do the strut mounts same time

md21722 · #14 04-04-2003, 03:33 PM

Bzoo,

Did you happen to see how much your lower control arm bushings were stretching when you did it this way? If they didn't hold that spring you might be dead.

csnow · #15 04-04-2003, 04:00 PM

Yikes!

I do not think it is possible to 'let the wheels hang'.