coupenut: Alternator, Running Gear and Belts

Trying to drive the car every day lately. Partially to shake it down and make sure it's perfect, partially just because it is kickass to drive an M coupe everyday! I noticed when the car is warm there is a sound from the main belt drive. My guess is it's the alternator bearings. Previous owner had already installed a Stewart water pump, so I am guessing that part is OK. Will know when I get in there and check. I do plan on upgrading the entire cooling system and add an oil cooler and S54 oil filter housing to this car, but I am delaying that work for a while. I did already replace the coolant so hopefully I can wait a bit longer. Anyway, I figured while I am doing the alternator, I might as well do the belts and pulleys and all the running gear. For parts, I bought a remanufactured Bosch alternator from Rockauto. This is the original Valeo alternator, rebuilt by Bosch. The other parts are all OEM, but not BMW labeled.

When I removed the parts that were on the car I noticed a few things. Firstly, the alternator bearings feel OK to me. No play I can feel. Worst case I got a nice "new" unit that will be trouble free for a long time. Also noticed that the fan nut was hand tight. As in, I didn't even have to counterhold the pulley to remove it. Not good, I think. I know the belt rotation keeps trying to tighten the fan nut, but if a fastener can be torqued to spec, damn it I am going to torque it. I do have the correct BMW tools to tighten the nut, so I can fix it properly. But, I also noticed that the fan clutch didn't feel right. Too loose. I could buy a new fan clutch from BMW for $272.38 or the identical Behr part for $86.40 from FCP Euro. Deal. Let's do that too. Lastly, the tensioner looked OK but the bearing and seal in the tensioner assembly was leaking grease from the bearing, see pic. More than likely, I am guessing that one part was the cause for the noise. All that said, I was going to replace all of these parts sooner or later anyway. And the belts did have microcracks in them and have 2008 dated on them.

I will say that the S52 cooling system is less fun to work on than the S54. As far as I can tell, you cannot remove the fan shroud on the S52 without disconnecting some/all cooling hoses. Since I just put nice new BMW coolant in the car, I didn't want to do that. So I did all this work with the shroud in place and the car on the ground (nothing from below). The S54 is different, you can remove the shroud without disturbing the coolant lines. S52 means lots of small cuts on your hands!

BMW AC Drive Belt - Contitech 5PK906, $9.99r
BMW Accessory Drive Belt - Contitech 6PK1555, $14.99r
BMW Accessory Belt Tensioner Kit - INA 11287838797KIT , $64.12r
BMW Drive Belt Idler Pulley - INA 11287841228, $21.99r
BMW Pulley Protection Cap - Genuine BMW 11281730349 , $3.08r
BMW A/C Belt Tensioner Damper - INA 11281717210, $43.99r
BMW Drive Belt Tensioner Pulley - INA OEM 11281748131, $14.99r
BMW Pulley Protection Cap - Genuine BMW 11281727159, $4.49r
BMW Protective Cap - Genuine BMW 12311713143, $2.39r

Bosch AL9414X Remanufactured Alternator, 115 amp, $143.00r plus $75.00 core charge
Behr Fan Clutch, BMW part number 11527505302, $86.40 from FCP Euro