Coil Spring Compressors - PeachParts Mercedes-Benz Forum

RadioTek · #1 10-11-2009, 12:16 AM

While crawling around underneath my car, I seem to notice that the subframe looks like it has been replaced. The lower control arm attachment point doesn't have the little "ears", but there seems to be a "C" shaped box around the point.

I suspect that I might have to do the subframe bushings myself, then. I've been looking around for the spring compressors, and there seems to be 3 basic types: the dual disc type and the dual "W hook" type are both single screw units that go through the middle of the spring. The double outside clamp seems to come in two types of clamp, one hook or two hooks at each end.

Since the prices for the dual disc type specified for Benz, BMW, etc... run around $200.00 and up, and the dual hook external clamp can be had for around $30.00, I wonder if the less expensive ones would be enough to hold the spring while I work on it.

I plan on installing the compressor with the weight on the front of the car, tightening it up, then raising the front end. I don't want to compress the spring with them much, but just let the clamp hold the already squeezed spring.

Does anyone see any potential problems with this? I am probably only going to have to do this job once, so I don't need the Professional Shop type tool. The expense for the "right" ones would not be worth it, to me.

Does anyone have any comments or suggestions? All Ideas would be greatly appreciated, those with experience especially so.

Thanks, Scott

Deltacom · #2 10-11-2009, 06:29 AM

Hi Scott, the dual hook external compressors have a narrow curvature that would not hook onto the 107 spring diameter (and there is no room to fix them). The internal "W" compressor cannot be inserted inside the 107 springs with the subframe on the car and the brackets holding the hooks they come together before the spring compresses sufficiently to install/uninstall. They are utterly unsuitable for the 107. There are in this forum the correct Klann clone compressor for hire for the cost of the dual hooks ones.

Even then, in the 107 you will have to drop the subframe from one side to allow the compressor spindle to be inserted from the top spring cap. (see pic)

The alternative some guys undertake by dropping the lower control arm until the spring extends is suicidal (the road to the cemetery is paved with good intentions!).

Faced with having to drop the subframe one side at the time, why not consider removing the subframe altogether and replace engine mounts and subframe mounts in addition to bushings? And while it is out of the car you can give it a good coat of paint and 5 bibs spring caps as your springs will be a bit tired if they are the original ones. Just a suggestion which I carried out a few months ago and made all the difference. Hope this helps.

Roncallo · #3 10-11-2009, 07:37 AM

After doing it once with the 2 W hook $30 thing and realizing I was near death at all times, I decided to make my own. I used two plates and a 3/4" ACME threaded rod. You can see by the pictures the upper large plate has a welded on smaller centering plate and then lath turned, that pilots into the top subframe spring perch. The lower plate is lathe turned to form a cup that pilots over the lower control arm rolled edge on the spring access hole. This level of detail is probably not required and I only did it because I could.

Essentially two 1/4" to 3/8" plates with a 7/8" hole and a 3/4" threaded rod 24" long and 2 nuts are all you need to do this job safely. About $20 worth of stuff from Sears Hardware or HD. ACME threaded rod and nut are a nice option and available from MSC.

With this setup you will have to remove the two Z bar links, compress the spring remove the two lower control arm bushing bolts. Then unwind the spring making sure the threaded rod does not unwind from the top nut on the threaded rod. I will probably purchase another ACME nut and weld it to the bottom of the threaded rod to make sure I have a wrench hold to keep it from turning.

Very cheap, very effective and very safe as long as you keep an eye that you are not backing the threaded rod out of the upper nut!!!

donbryce · #4 10-12-2009, 10:41 AM

Here's an old thread decribing how I made my version of a compressor, copied from a copy of an original MB tool, made by an experienced and trained MB mechanic friend of mine. Not fancy, but it works and is safe IMO.Homemade Spring Compressor

meltedpanda · #5 10-12-2009, 02:52 PM

dont underestimate these springs, if they get away from you they will go through anything in their path - they can kill you ,so please dont use any work arounds or inferior tools

neds380sl · #6 10-14-2009, 01:05 PM

Panda (Melted?) is 1000% correct- be careful. My local rental shop rents spring compressors for not-a-lot of money. Have you tried that? Most of us don't have lathes, at least a lathe that works. My 9" Model A South Bend still needs to be set up.
Ned

RadioTek · #7 10-15-2009, 01:50 AM

Back underneath the car after I posted this and read a couple of replies. I think I'll really work on trying to rent the right compressor when it comes the time.

Those mothers are HUGE. I figure the energy stored in one of those things when compressed would be over in the 'fatal' category.

Thanks for the info on what to look for.

Scott

meltedpanda · #8 10-15-2009, 09:59 AM

no doubt - safety first