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

dmorrison · #14 04-19-2003, 04:36 AM

Ok
The top plate is relatively easy compared to the bottom. As you see it is a 3/8 metal plate with the same groove milled into it that will be done to the bottom plate. The size has to be determined,
The center hole will be the same size a the A hole ( again don't take it personally) so the bolt head can slip through the top plate as you are assembling the coil spring compressor.
If you look at the side diagram, this is how I think the top bolt should be shaped.
Because the bolt shaft will be smaller than the opening A. I was thinking of a "centering " system so the threads of the bolt are not damaged while compressing the spring. If not held in the center of the A hole ( oh never mind) then they could be damaged.
The nut needs to have a large amount of threads gripping the threads of the bolt. To little threads holding the nut and bolt together means the unit flys apart.
This is what caused the Alaska Airlines MD-80 crash off the California coast. Lack of grease on the screw and the crew kept forcing the trim system to work. They wore down the treads and the aerodynamic forces on the screw stripped the nut off the bolt and the T tail came off the aircraft with it.
I digress!!
I would consider a 2-3 inch long coupling nut if we can get it out of Grade 8.
To center the bolt shaft in the hole. A washer could be cut with a tube that will go down the A hole. This will center the bolt shaft and with enough grease we should be ok. If the nut is large enough it could be turned on a lathe so the bottom of the nut fit into the A hole and a washer would add more surface for tightneing. The washer could only be 1 5/8 " max to allow the washer to fit in the 123 spring perch hole. Unless another car had a spring perch hole that was smaller.
The washer assembly could be welded to the nut.

One last tool. To get to the top tightening nut I designed a tool that would allow you to use a rachet, not a impact wrench, to much force.
Either use a plumbers tube. They make long tubes for plumbers that are hollow and have certain size "sockets" stamped into the ends of the tube. We would have to find the right size and lenght.
Or you take some square or round steel stock that has a inner diameter larger than the bolt shaft diameter. Weld a socket on one end and a bolt on the other. Make sure its long enough so the bolt shaft doesn't reach the top bolt. The top bolts will be used to apply your rachet to tighten or loosen the coil spring. The socket will have to be cut to allow the bolt shaft to continue through it.

Well critique away.

Dave