PeachParts Mercedes-Benz Forum - View Single Post - Request to members in Germany

dmorrison · #24 04-15-2003, 03:22 PM

Well, I have to chime in here. I of course have designed a coil dspring compressor that I was going to make. I was designing the concept after the Sir Tool/Klann plate system. The attached diagram is the design I came up with for the plate. I was going to have a 18 inch grade 8 bolt cut at a local shop here for $40. The problem I see is you have to insert a bolt from the top down to the plate that will be inserted through the spring coils and then capture this unit. You have to prevent the plate from slipping right or left. The squiggily lines on my photo represents the depression milled or ground into the plate. The 90 degree cuts will alow the plate to be inserted and then as the coil winding increases, the coil will bypass the plate, at the 90 degree cutout and raise up through the opening. The grove will help prevent the coil from moving. The fact that the disk is 5" in diameter prevents the plate from slipping through the coils and slip off the coil spring. Sort of the manhole cover idea. The manhole covers are round so they can't slip down the hole. Any other shape could slip down the hole.
You have to keep the spring as straight as you can. Even with the Sir tool I found that the coil would tilt at times. But it was controlled.
The opening in the disk will allow the bolt to slip into the opening and center in the disk. the bolt washer has 2 roll pins that will go into the holes drilled in the plate. This is to prevent the plate from rotating and driving itself up the coil spring.
The top washer would go over the top opening. I was going to again use grade 8 nuts, hopefully a 2" long nut to tighten the assembly. And some grease on the treads and the top hole washer. The top left item shows the 2 washers that would make the top washer. the smaller diameter woul dcenter the bolt in the top holeof the spring perch.
Additionally I woul dconsider welding some guides in the plate to prevent it from slipping off the coil and hold it steady in the center of the coil spring.
I was looking at pulling the spring into the top pearch and then releasing it . I was going to change the springs out. I feel this would have worked. But was concerned about the deadly compressed energy. I chose to buy the Sir tool.
Thomaspin has a wonderfull milling/lathe unit and I'm sure he could make on of these plates. Maybe he will give it a try.
The dimemsions are for the front springs only on the 123. The rear springs used the larger plate that came with the Sir Tool.
I can measure it if anyone wants it.
The rear spring. You would remove the shock or hydraulic shock and insert the plate at the top. The lenght of the rod may have to be different then the one for the front.
You would then screw the spring down to the trailing arm. Remove the arm and then you could release the spring for replacement or leave it attached while R+R the bushings.
I did find that with the Sir tool I still had to have the subframe bushing bolt released and the front subframe lowered about 4-5 inches to get the spring installed.
The Sir tool and maybe the Klann will compress only so far and you have only 5 coils to compress or you can't get the plates out once you release the tension. Therefor the spring is not compressed tightly as shown in the Mercedes service manual. A limitation of the Sir Tool.

Dave