Broken springs - PeachParts Mercedes-Benz Forum

tower · #1 12-22-2006, 06:44 PM

It looks like at least (1) spring is broken on my S420 (1995, rear passenger side for sure). Owing to the preceived safety concerns and not owning a M-B spring compressor, I was wondering if anyone has had success in banding the spring. For those unfamilar (as I am) with the spring banding concept, apparently they compress the spring and band it with 5 or so steel straps. The compressed spring is then inserted into the spring saddles in its compressed state. The specific wheel is raised so that the saddles contact the spring. All that remains is to cut and remove the steel straps.

Best regards to all.

Tower

Kestas · #2 12-22-2006, 06:56 PM

Compressed springs hold a tremendous amount of force. I don't think banding straps are designed to handle that much load. The only thing that would keep it from flying apart is the crimp in the band... not a warm fuzzy feeling. I wouldn't do it.

tower · #3 12-23-2006, 11:57 AM

Thanks Kesta. I'm somewhat aware of the potential energy stored within a compressed spring, but I am led to believe they do this with "truck" springs for installation. Like I said, I've never seen it done and was wondering if anyone on the board has experienced it or otherwise.

manny · #4 12-23-2006, 12:23 PM

When I changed my front springs, my own spring compressor would not install my new springs.
Went to a springshop & had them banded.
They must have installed about 10 bands on each spring.
Installed the springs, raised the controlarm, and cut 1 band at a time, to release the new spring.
Worked like a charm.
Just be careful.

Btw. on my rear springs I did not need a compressor at all.

tower · #5 12-23-2006, 01:24 PM

Manny.....how did you cut the bands, pair of pliers or torches.

jim16671836 · #6 12-23-2006, 03:06 PM

Most of the Mercedes cars I have messed with did not require a rear spring compressor... I have not messed with your model... I jacked up the car and installed jack stands... then I disconnected the sway bar and put the floor jack under the spring I was removing first.. Removed the nuts from the top of the shock and lowered the spring perch until the spring had no tension...

You might ask others if this is possible with your car... I have used this method on the 116, 123, and 126 models.......... Jim

manny · #7 12-23-2006, 03:07 PM

Tinsnips......really!
They just used the same steel banding as used on shipping crates.
Cuts pretty easy, but they are very strong.

tower · #8 12-23-2006, 03:30 PM

I'll try without compressing first and use the compression banding in a fall back position. Thanks for everyone's input.
Ron

tower · #9 12-23-2006, 10:37 PM

Thanks for your concern, but the passenger side rear spring was seperated by 1/4" where it was broken. I didn't see a break in the driver side, but it could be broken as well. I suspect it is not broken and that the stabilizer bars are transfering the load from the passenger side to the driver side. I'll obviously replace both springs and find out during the removal.

PS. Living in Southern Ontario I know all about the rust belt though

tower · #10 01-04-2007, 05:36 AM

Yesterday I drove to my brother's to take advantage of a warm garage and cutting torches in this spring replacement task. Results were very gratifying. If anyone has need to replace springs like this I highly recommend using this method of banding. Makes the job easy. I apologize to the masses now as I fully intended to take pictures but the camera got left behind. Its this over 50 brain.

Some notes. I replaced the rubber spring seats as well as the spring proper in this case. Upon removal of the springs (via one side at a time), the passenger side was broken in (2) places (in the bottom housing and 1 coil from the top) whereas the driver spring was broken in the bottom housing only. This vehicle does not have the hydraulic suspension so we removed the bottom shock bolt (most difficult task of the day), repositioned the shock away from the frame and proceeded to torch out the remaining spring bits. A long bar was necessary to pry the wheel assembly down about 1/2" so as to provide clearance to insert the compressed/banded spring. Then jack the wheel hub up with a jack to release the loading on the bands and snip away. The guys that banded the springs did a good job in securing them with 6 of the bands per spring (and yes it the same 3/4" crate banding material). They also knew enough not to band the top and bottom coils.

As I said fairly uneventful. Total job took about 4 hours total (book calls for 3.6) but we replaced one of the suspension struts at the same time and that took about 1hr because I couldn't get the wheel side mounting bolt to free up without Rube Goldberging it (missing 12pt "star" socket).

Anyways, car sits much better now and I didn't get (1) headlight flash coming home (car sat low in the back so headlights tended to shine into on coming traffic operator's eyes). Now the only thing left is to find the bongo drum knocking in the rear and identify the steering wheel vibration cause at 100kph. Currently travelling below 100kph with the radio on.

Ron