Front Spring Removal - As I thought, simple without special compressor - PeachParts Mercedes-Benz Forum

BIGRED · #1 01-11-2004, 02:52 PM

Months ago I brought up a concept. To remove the front springs, without using a compressor, by lifting the car off the spring.

Well I had some fool around time in the last couple of days and it was in the end simple. I did this on a 126. I went very slow and checked and double checked each action. I wanted to learn as well as pull the spring. While I spent several hours pulling my first spring. I am sure I can pull it start to finish in 30 minutes.

1. I raised the front end and supported the body with jack stands
2. Using a floor jack near the lower ball joint, I lifted the car just a bit more than jack stands.
3. I removed the wheel, shock, upper control arm and the brake hose.
3. I very slowly lowered the floor jack. I found that the guide rod was adding support and therefore holding the wheel up a bit. Being the spring is about 19 inches and at this point 17 inches was already released, I was not to worried about the amount of tension left, however I clamped on a pair of coil spring compressors (that cost about $10.00 at Harbor Freight) for added safety and shoved a breaker bar through the top opening of the spring (via the engine compartment). I found the last steps a bit over kill but safe.
4. Stepped on the front control arm, which pushed it down about 2" and then using a pry bar, popped out the spring.

When I removed the clamps, I measured 1" to 1 1/2" of compression, I don't think enough to cause any danger, but they added some control and peace of mind.

On the next wheel I am going to pull off the guide rod (bearing support) before lowering the wheel. My guess is that the spring will fall out.

Don

sixto · #2 01-11-2004, 03:04 PM

That's very good to know.

What's the safety purpose of dropping a breaker bar from the top of the spring?

As an aside, why is it not possible or recommended to drop the rear guide rod mount and forego the business of manhandling the lower control arm when working on the guide rod?

Sixto
95 S420
87 300SDL

BIGRED · #3 01-11-2004, 03:18 PM

If you do a search on "spring removal" you will find that there is a high level of concern which generates unfounded fear about the "power" of the springs. I shoved the breaker bar down in there in case something popped. The thought being it would help contain the spring in the wheelwell.

Same goes for the guide rod and bearing. My fear caused me to leave it in place to help control the spring. On the next wheel, I will be pulling it ahead of the spring.

I think most people have either thought to or in fact tried to use compressors to compress the spring from a relaxed to a tight state. I think thats where the trouble comes in. My goal was to fully relax it and work on it in a relaxed state if possible (and it was possible!)

Don

coachgeo · #4 01-11-2004, 03:59 PM

I guess the question still remains if this method can be used to reinstall new springs that may be taller compated to old wore out ones.

BTW... the drop and tug out method of removing springs is the common way they do it with 4x4's on coil springs. Then again though a true offroader is never afraid of axle droop. We want it!!

sixto · #5 01-11-2004, 04:02 PM

With the guide rod out of the way, what limits the swing of the lower control arm? Seems like it'll drop to vertical when left to its own.

Sixto
95 S420
87 300SDL

shane83SD · #6 01-11-2004, 04:56 PM

Just came back from the bone yard. Saw an example (81SD?)of "drooping" spring and lower control arm, they are still attached to the car. The other suspension parts are all gone. The lower control arm is hanging near vertical, and one end of the spring is caught by the lower control arm. The spring is bent slightly.

I think BIGRED is onto the right track. However, a heavy duty flat rope may be better for safety, since to R/R the spring in this state, slight compression is needed.

engatwork · #7 01-11-2004, 05:20 PM

shane - you rung a bell. Now that you mention it I have seen the same thing as described on a 190 class in a pullaparts place. I was scared to get near it at the time

.

Bigred - have you put the spring back in there yet? I am assuming that you will be able to use the regular spring compressor to pull it in enough to slip it in.

BIGRED · #8 01-11-2004, 05:49 PM

I did the experiment on my 300SD parts car, so no I have not yet put the spring in. I am planning to rebuid both lower control arms and bearing mounts from the parts car and then install them on my daily 300SD. I don't think I will need to use any compressor to put it back. It looks like I will swing the control arm up untill the spring case makes contact with the bottom coil then start pumping up the floor jack.

BIGRED · #9 01-11-2004, 05:57 PM

Quote:

Originally posted by coachgeo
[B]I guess the question still remains if this method can be used to reinstall new springs that may be taller compated to old wore out ones.

Based on the factory CD, the springs I pulled are very close to the height spec's for new ones. While I have not yet done it, I have no doubt or concern that it will go back very easily. Remeber with everything disconnected from the lower conterol arm, you could swing it from 9:00 (normal driving position) to 6:00 without any problem. (if the car is high enough off the ground).

Don

#10 01-11-2004, 07:24 PM

Have fun putting it back together, I found it easier to remove than install. That spring is tough...

dmorrison · #11 01-11-2004, 09:07 PM

Well I must post here.
Let me say first of all that I do own the Sir tool Compressor. The desision to purchase it has quite a multitude of facits so I'll just say that of course I use the Sir tool.

My brother is a mechanic on Mercedes and he described this method of coil spring removal to me also.

They use an external coil spring compressor to slightly compress the spring. One like this.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=43753

He describes the proceedure as

They raise the car up on the lift, jack stands for you and I.
They place a jack under the lower control arm
The raise the lower control arm to compress the coil spring
They then install the strut compressor.
Then they lower the LCA to allow the UCA and LCA support of the coils spring to spread.
My brother said that you might have to use a crow bar to get the base of the spring out of the spring seat.

Installation may require the bottom of the spring to be nudged into postiton with a crow bar.

I was not comfortable with this method. Would hate to loose my career as a pilot by not doing it correctly. So I purchased the Sir Tool compressor.
If my brother was here guideing me I would have considered the task but he's in Columbia SC and I'm in DFW.

Dave

PS a concern with a taller coil spring is of course a concern. The new 123 springs I put in the 300Td were in fact 1 inch taller than the OEM springs. I called Lemforder in England to make sure I had the correct application for my car. They informed me that the spring rate was the same but that they were taller.

R Leo · #12 01-11-2004, 11:15 PM

BIGRED,
Next, let's see you use that procedure on the rear springs.

dmorrison · #13 01-11-2004, 11:54 PM

As R Leo has of course pointed out, I never would have gotten the rear suspension rebuilt without the Sir Tool Compressor.
The rear suspension rebuild was a complete rebuild. New springs, trailing arm bushings, subframe mounts, sway bar mounts and ends, differential mount, repainted the trailing arms while they were out. Removing the spring!!! I don't see how you could do it without the compressor. Actually I could probably figure out a way to remove them BUT not install them.

Dave

BIGRED · #14 01-11-2004, 11:54 PM

Quote:

Originally posted by R Leo
BIGRED,
Next, let's see you use that procedure on the rear springs.

I won't be getting to re-building the rear for awhile, but intend to drop the entire sub frame assembly including the rear end. I see no difference in the rear. Unbolt everything and raise the body until the springs can be removed.

Don

BIGRED · #15 01-12-2004, 12:09 AM

Quote:

Originally posted by dmorrison
Well I must post here.
Let me say first of all that I do own the Sir tool Compressor. The desision to purchase it has quite a multitude of facits so I'll just say that of course I use the Sir tool.

My brother is a mechanic on Mercedes and he described this method of coil spring removal to me also.

They use an external coil spring compressor to slightly compress the spring. One like this.

http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=43753

He describes the proceedure as

They raise the car up on the lift, jack stands for you and I.
They place a jack under the lower control arm
The raise the lower control arm to compress the coil spring
They then install the strut compressor.
Then they lower the LCA to allow the UCA and LCA support of the coils spring to spread.
My brother said that you might have to use a crow bar to get the base of the spring out of the spring seat.

Installation may require the bottom of the spring to be nudged into postiton with a crow bar.

I was not comfortable with this method. Would hate to loose my career as a pilot by not doing it correctly. So I purchased the Sir Tool compressor.
If my brother was here guideing me I would have considered the task but he's in Columbia SC and I'm in DFW.

Dave

PS a concern with a taller coil spring is of course a concern. The new 123 springs I put in the 300Td were in fact 1 inch taller than the OEM springs. I called Lemforder in England to make sure I had the correct application for my car. They informed me that the spring rate was the same but that they were taller.

I don't like the idea of compressing the spring with a tool. I think thats where people not using the MB tool get into trouble. When I say compress, I mean anything more than an inch or so.

With everything unbolted, the lower control arm will drop at the rate you raise the car until you can lift the spring out. I can see no reason to compress it with a tool, unless your trying to save the time of pulling the shock, caliper and upper control arm.

While I am sure other models may be different, on my 126 the relaxed spring is about 19". When setting on the 4 tires it is compressed to about 12". That means that using a tool, I have to control about 8" or 9" of spring compression (no thanks). I feel lots safer having the weight of (or lack thereof) the car compress or relax the spring.

Don