I'm doing some major work on my 2013 R60 and wondering if there are any other parts I should replace while I'm in there.

I am in the process is replacing the clutch, timing chain, front control arm bushings, and turbo wastegate flapper valve with the help of a seasoned mechanic. Sub-frame is off, transmission is out, crankshaft out, valve cover off

 

The easy things would be motor mounts, and engine and transmission seals. In your other thread, you’re on a budget, else I would suggest maybe an LSD, unless it’s an All4 model. Be sure to check the condition of the water pump pulley and friction wheel, and have a new alternator belt on hand.

 

Motor mounts and seals are a good idea. I am planning to do the belt. It is any All 4. Not sure what the friction wheel is all about, I'll look into that. Are there any sensors down there I should clean or replace?

 

If you look at the accessory drive system on the engine:


Looking at the picture above, the crank pully is in the middle, the AC compressor is lower right, the alternator is upper right and has the tensioner mounted above it, and to the left is the water pump pully. In between the water pump pully and the crank pully, the dog bone shaped contraption, is the friction wheel assembly. Due to packaging constraints, the drive belt doesn't directly go to the water pump. The friction wheel assembly transfers rotation to the water pump. The friction wheel has a rubber surface that can wear or crack, and the water pump pulley has a rubber surface that can wear and crack. All that stuff has to come out to replace the timing chain, so might as well put new stuff back in.

 

Thank you for that excellent picture and explanation. Interesting design to say the least...