A Frame Bushings
 

Judging by the looks of those lower bushings, you're going to love the improved handling .

Yes, ever since I got the car it clunked when I went over a bump. I replaced all the easy parts, and left the hard parts (lowers require spring removal) for last. I imagine the only way to replace the lower bushings is to remove the sub-frame. There is no hole in the body above the upper spring seat to put the spring compressor into. Since I had to modify the sub-frame for compressor fitment, it was a no-brainer to do the bushings.

Sub-frame notch
 

I started the work on the sub-frame today. I cut out the area that needed to be notched for the compressor with a cut-off disc. I used a piece of 1/8 thick sheet steel for the notch, bent in my vice. I cut the rough shape out with my metal cutting chop saw, and got it closer with the angle grinder. I welded it on all sides, and ground the welds smooth. I also added a gusset to the bottom. Only one side was done previously. I just need to clean it a little better, and then paint it.

Gusset
 

The gusset.

Cleaning and painting
 

Yesterday I got the parts cleaned and painted. The larger center portion I took to the coin-op car wash, and used my favorite degreaser to get it clean. A can of satin black engine paint was used to make it pretty. The smaller parts I cleaned with solvent, and then the degreaser. Everything got painted, including the engine mount spacers.

A/C compressor
 

While the sub-frame is out of the car, I figured it would be easiest to install the compressor. There is so much more room, and the compressor went in without any problems. However, with the compressor all the way against the block, the pulley rubs on the anti-sway bar. If I rotate it away from the engine, it does not rub. Hopefully there is enough room in the notch I made in the sub-frame that the pulley has clearance before the compressor hits it. I will probably find out today, as I have the parts and hope to get everything put back together before dark.......Rich

Sub-frame install
 

Yesterday I continued the work on the sub-frame. Cleaning parts, painting them, and installing new parts. I used my "C" press to press in the ball joints, and a little silicone spray made the lower bushings just slide right in (with a little help from a hammer of course). Using two floor jacks, I was able to get the completed sub-frame up into place.

I ran into a problem. I picked up the left side spindle/rotor assembly to clean and paint it, and when I was cleaning it, I noticed an R stamped into the forging. I thought that maybe when I took the joints off the spindle, I had the sub-frame turned around. I cleaned and painted both sides, and proceeded to install the one marked R on the right side, and the L on the left side. Makes sense, right? After jacking up the sub-frame and bolting it up tight, I tried to put the steering arms on the spindle. I noticed that the brake caliper was in the way. It was then that I realized that I put the spindles on the wrong side! Evidently, these are made for other chassis (W115?) that have "front steer", and the R107 is "rear steer". I thought about what a hassle it would be to remove the sub-frame, take out one spring at a time, and switch the spindles. After thinking for a moment, I figured I could set the lower ball joints on stands, and the weight of the car would keep the springs compressed so I could remove both spindles safely to switch them. That plan worked perfectly! I got it mostly put back together, and will probably get back to it today. Another problem is that the anti-sway bar is hitting the A/C compressor pulley (second photo post 186 above. With engine lower, sitting on it's mounts). I will have to fabricate some brackets to lower the mounts. Stay tuned.............Rich

Nice work! Are you using a sand (media) blaster?

Although a blast cabinet would be a good thing to have, I did not use one. I have kept everything pretty clean, so it only took some degreaser and a pressure washer to clean the large parts before painting. For the spindles and backing plates, I just used a rag and lacquer thinner to clean them.

Anti-sway bar
 

After thinking about it for a while, I came up with a plan to lower the anti-sway bar mounts. I found some flat bar stock the same width as the mounts, and cut four pieces at 5". This will lower the bar a little over an inch. The plan is to sandwich the existing mounting surface with two pieces each side. I drilled three holes in each piece, the top one for the former top bushing mount, and the two lower holes for the new mount location. I had to drill the center hole for the new upper mount bolt. The passenger side mount has the tow hook, and the bottom of the mount is closed off with metal. I had to cut it out to gain access to the fasteners.

Part 2
 

I got the anti-sway bar mounted with no problem. Also, there is plenty of room for the compressor now, both at the sub-frame and the compressor pulley.

A/C work
 

I finally got all the A/C components hooked up, and ready for a vac and charge. The hardest part was the suction hose connection at the expansion valve. It is way up in the dash above the pedal assembly, and not easy to get to. I had a friend make an adapter from the flare fitting to O ring. I made the other three hoses, two of them having inline R12 charge ports. I went to my local radiator shop to pressure test the system= NO LEAKS! Since I have all the equipment to charge R12 (gauge set, vac pump, R12), I figured I could do the job myself. I started the engine and turned the A/C on. The compressor clutch did not engage. I checked everything I knew to check, and just decided to hotwire the clutch in order to get it charged up. I figured I could sort out the no power problem later. I put in enough R12 to make the bubbles go away in the sight glass, and the vents put out cold air. After trying to figure it out for about an hour, I decided to call it quits for today, and get on my computer and do some research. Next time I have to work on it, I will be looking into the compressor relay and temperature control unit. I am not sure where the compressor relay is, but the temp control was checked/repaired by jamesdean, along with the PBU and fan speed control. I doubt any one of those is the problem. Anyone know where I can find a wiring diagram and relocation for the '85 308SL? I looked a little, but did not find anything very helpful. Thanks, Rich

Rich, if you go to startekinfo, mbusa have manuals for all the 107s on-line. The electrical diagrams should be there. Same place where they have w123 FSM.

I believe the front suspension on the 107 is pretty much all 115 chassis.

Excellent work Rich! I would not be brave enough to cut open important things like the crossmember and weld in new parts....of course I might feel differently if I could weld like you can.;)