I have a 1987 w124 300TD that is my project car. It runs well and looks will improve. My problem is that I think the right rear wheel bearing is howling. Is removal and installation of new rear wheel bearing beyond the home mech?

 

I thought that it was so I took both rear sub assemblies off and brought them to a reputable shop in California. I live in Arizona and it was a 6 hour drive. The biggest problem I was facing was the removal tool for the actual bearings. Basical a sprag wrench. A large diameter socket with tabs sticking out that fit slots in the take up nut. Anyway I get these back and installed one side. I knew I was in trouble when I could shake the tire 1/2". I had to make the sprag tool. Diassemble everything and redo the whole job. Those timken bearings have to be installed with a slight load (very slight) or else they will burn out faster than if they were overtightened. Keep in mind that you have to remove both axle shafts to even get to the nut that releases the rear wheel shaft. Whatever you do do not try and use a punch to loosen the takeup nut. You can get it off OK but you have to compress a new inner bearing collar and you need the tool to get the correct load on the bearing. The specs call for .001 to .003 tolerance after tightening. The shop I took them to left them around .090. The mechanic blamed the poor work on the fact that the rear assemblies were not in the car so he could tighten them down properly. Most shops in the know change them while on the car but then they have the right tools. If you do it once (properly I might add) you probably will not have to do it again in your lifetime. At least that is how I figured it out for my car. It took me an hour of machine time to make the tool or you can but it from MB.
Hope this helps.
Myron