Hi Alex,
I sure can relate to the feeling of being overwhelmed. If you've caught any of my posts over the last few months, you'll know what I mean. I had no intentions of doing this extensive job on our SL this winter while dealing with a wife going through cancer / chemo and a torn rotator cuff myself. My wife wants a road trip in Ms Magoo this summer for our 46th anniversary and I hope to giver her that.
I just finished what you are now starting, except I had the flex joint / yoke snap last fall for no real apparent reason. We've toured the country for 21 years and 65,000 miles and maintained the car meticulously in the process. However, the car is 57 years old and the yoke is a weak spot in the early SL's I guess.
I removed the axle in two halves and put it on a bench in the middle of my garage where I could work on both sides of it without lifting it. After much consideration, lots of research and consults with this list, this is what I ended up doing. I disassembled the diff. completely, removing both axles, ring gear etc. I left the pinion gear in place.
After checking all bearings, I found none that were even slightly faulty. Everything in the differential looked as new. I replaced the flex joint with one from the exact same year 113 car. After a lot more consideration, I replaced the inner axle seals, split boot with solid boot. I also replaced the pinion seal. I left the outer grease seals and bearings alone. They looked to be in perfect condition and could come up with no reason to mess with them. I also replaced all rubber bushings, including springs, and compensation spring rubbers.
Sometimes I just do myself more harm fixing something that isn't broken, so I opted not to remove those outer bearings. I cleaned and packed the outer bearings, replaced all brake hoses, cylinders etc. and put the axle on the floor and bolted it back together and filled with new synthetic oil. I cleaned the axle with simple green and painted it up nice. I also painted under side of the rear.
Some would say you should replace / rebuild everything including all bearings. Well, if I had the slightest doubt about anything, I'd replace it. The only seals i didn't replace were the two outer axle grease seals, which looked perfect to me and absolutely nothing was getting into the brake drums either. in my opinion, the inner axle gear lube seals are the ones to be concerned with. If they leak, you have a real mess on your hands. if for whatever reason I feel I should replace the outer grease seals sometime, I'll just pull the axle out and replace them and slide the axle back in.
I've now installed the axle back on the car and replaced the entire brake system, front to back including master cylinder. Booster was replace a few years ago.
Now I'm ready to put the car on the ground and I started the car and for what ever reason I have this nasty, loud, intermittent clatter sound when I start or run the engine. Blows me away. I can't figure what it is. Murphy's law i guess. This is driving me absolutely nuts. I will remove valve cover tomorrow and start checking timing chain, valves etc.
Try not be be overwhelmed. Once I got started, my job was a much easier job than expected. Very straight forward stuff if you ask me. I only had help putting it back in the car, so it wouldn't fall on me. I strapped the axle to a 2x4 to keep it from flopping and used a single floor jack, connected the trailing arms and trunk mount.
Best of luck to you.
if you have questions, just ask. Lots of help from this great group.
Ed Riefstahl
1966 230SL (Ms Magoo)
1970 280S (Miss Daisy)
1989 300SE (Majestic)
1999 BMW Z3 5 speed
1991 BMW 318I 5 Speed
1997 Toyota Paseo Convertible - Red 5 speed (have you ever seen one?)
1997 Ford Ranger step side (Mater)
2023 Mazda CX 5
