What, exactly, necessitates the use of an MB spring compressor?
 

Was talking with a friend today and mentioned that I can't use a typical parts-store spring compressor when doing the coils in my 240D. He asked me why, and I realized that I don't actually know. Why do we need the MB compressor? What's wrong with the parts-store variety tool?

the mb compressor comes up through the hole in the control arms in the rear and down through the body in the front, is far more secure, far easier, and far safer in how its designed to work from inside the spring.

though I will add its nice to have a parts store compressor to grab the outside of the front springs to straighten them slightly because of the curve which can make things difficult

Several Members including myself have tried the outside Spring Compressors (mine were from harbor freight) and had the slip and bend the threaded rods n the compressor. Fourtunatly no one on this forum has been injured.

The reason the typical spring compressor cannot be use is that the Front Springs must be something like 4 times as strong as the Springs on even a large US Cae.

Lots of threads where Members have use the copies of the Klann Spring Compressor which runs around $80-$90.

On the Rears you don't need a Spring Compressor depending on what you are doing. But, before I knew that I removed and installed another Rear Control Arm and I used the Harbor Frieight Spring Compressor for that although I had some issues with having enough room to use them.

In My case since I mangled up the Harbor Freight Spring Compressor set I had I made a Spring Compressor that operates in the same manner as the Klann does and anther Member previous to me also made one.

And, someone made one using an extra set of lower Spring seats and ACME threaded Rod.

Later I also made what looks like the typical Strut type outside Spring Compress with on hook on eac end but I made it with 1 inch threade Rod. I tested it twice and it works OK.
I made that because I wanted a tool that could possibly be used on something else besides a Mercedes.

There should be more then several threads on the subject and what people have used. Just search with the word Klann.

Essentially the problem is space. There's not enough of it to safely attach the external spring compressor on the front springs of a W123. Not only are these buggers monster bollock eating death demons but they are rather long too. The "standard" smaller sized external spring compressors are just not up to the job. Far too wimpy.

The MB springs are rather long when uncompressed, and need to be compressed a lot in order to come out (which loads them tremendously), so regular compressors are a) not strong enough, and/or b) don't have enough range.

The first time you compress one of those front springs, you will immediately appreciate (and fear) the amount of energy stored by that compressor.

Those auto parts loaner ones are for Hondas and ΚΙΛ

It can be worth your life to not take every effort to make it as safe as possible when removing the front springs. Offhand I can not think of a more dangerous job on these cars unless done with the proper type spring compressor.

Fyi that compressor you borrowed is a clone and just a hair too big for the bores on the front springs. You will have to enlarge the holes with a dremel

Exterior ones won't fit in the space you have to work with and usually you can't get them high enough on the spring to compress the spring enough to get it out safely.

It's been pulled off a few times with parts store ones. But as stated once you do the job with the proper tool, it will make sense and you'll quickly go buy one for your own garage if you plan on buying more benzes.

Forget what your friend said, or thinks. Maybe he doesn`t.

As mentioned use the proper tool to remove the MB front Springs.
There are probably 100 plus threads on the subject. Here are a few I located.
All from Peachparts.

https://www.google.com/search?q=site+peachparts,+spring+compressor&biw=1093&bih=521&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjJ hcqfj6XMAhWhDpoKHYvlD1oQ_AUIBygC


The Spring Compressors you see on E-bay are a copy of the Klann German compressor.
They work ok for the DIY guy. I think Roy (WHUNTER) said they are good for 50 or so uses.

On the W123 you need to slightly open up the hole to get the rod down through the center of the spring.
On the W126, the hole is large enough w/o making it larger.

As mentioned, on the rear springs you do not need to use a compressor.

The front springs have a lot of OOMPH, and when one comes loose from a cheepie compressor,
it will fly out from the wheel well along with your head through the shop wall. :eek:

Hey Joseppie, where ya been when the Compressor threads were floating around. :confused: :)

Iam in the process now taking the 80 240D front end apart to replace everything. I will be using my MB compressor, if it hangs together pulling the springs
I`ll be back. other wise, :eek: nice knowing you on the Forum.

PP order should be here sometime today. Yeah. :D


Charlie

As an added bit of advice, do NOT use an impact gun to compress the spring. Yeah it works but it is easy to over compress the spring. While this has no effect on the spring itself it is very harmful to the plates and locking lugs on the compressor.

I've seen 4 or 5 sets of spring compressors destroyed or damaged in this manner. Every time I use one I go back and examine them. They'll "scuff" and create a burr where the lugs seat after 3 or 4 uses. IF you stay on top of the wear it's an easy clean-up, usually entailing the use of a Dremel tool and a bit of sand paper.

Hand tools only. A 1/2" ratchet is plenty enough tool to do the job. This serves multiple purposes.

A: You don't over-tighten the compressor
B: You reduce the chance of ruining the plates/screw assembly
C: You develop a healthy respect for the force needed to contain the spring along with quenching the desire to "rush" the job.

There's something to be said about how much the "pucker factor" increases the first time you hear the spring creak as the plates seat solidly.:eek:

MIKE D, thanks for mentioning not to use an impact gun.
I was thinking about it but forgot to type it in.

Loaning out a Spring Compressor if you have one, ya never know it they used an impact gun or not.

Always make double sure that the 3 fingers or nubs are locked into the detents of the lower plate real well
before tightening down on the rod.
Sometimes they can be a bugger to lock in if there is a curve to the spring.

First time I used one was at PNP to remove a set from a 240D. The way the cars are set on the wheel stands,
the suspension hangs down and the springs have a curve. A jack would help but are not allowed in the yards. I got the damed thing stuck
and thought for sure I lost it. Closing time was close :eek:.
Forget now what I did, but did finally get the two springs out.

I think you need to have the plate set to compress at least 8 coils of the spring. Or it is difficult to lift the spring out.
I`ll have my mind refreshed here soon with the 240 project.


Charlie

Charlie don't take any safety chances if you need help let me know, I'm in Carson and have the time. Safety is the most important thing. Plus if you're gone who will post sarcastic replies? (Just kidding there are plenty others).

The older benz springs are still under tension even with hanging suspension, meaning they are about 1/3rd more length of what you see when your car is road ready level.

And comparitivley, if you look at the Mercedes springs and other regular cars they look like to be from a railway car or a Kodiak truck, Don't take this risk. They are immensely powerful units, use the correct tool to handle them.

Thanks Steve. I won`t be working on it tomorrow but be back on it Monday
If you want to come buy let me know so I can get my dusting done. LOL :D

I worked a couple hours today. yesterday I pulled out the Upper Control arm.
Today when I removed the lower BJ nut, the steering knuckle just dropped off w/o having to use the BJ separator.
That was nice. :)
Used the HF Tie Rod Seperator and they popped right off with a BANG.

Used a die grinder and a rasp to grind out the hole to get the Spring Compressor in.
High Carbon Steel Rotary Rasp Set 10 Pc

put in the two plates, then turned the lower on down and the upper one up as far as it would go.
Dropped in the shaft, and made sure the three nubs locked into the three detents on the plate.
Placed a screwdriver under the lower plate to hold the rod in place while turning the rod to snug it till is was securely locked in.
Then from top side turned the nut with a 19mm deep socket and 3/8 Ratchet.
Tightened her up. lowered the Floor Jack, and a little wiggling, she came free.
Laid her on the floor and released the tension.

OH forgot, you need to remove the Shock

One thing I need to mention.
With the Upper Control Arm removed. The Shock will hold the Lower arm from dropping to keep the Spring from flying out.
Though I do not trust the Shock to hold things.

I had a 3 ton Floor Jack under the lower arm to hold it.
Install Compressor, secure it.
Then remove the Shock. and lower the Jack.


Charlie