I've developed a noise when rolling down the road and turn the wheel left. Sounds like its from the driver's side leading me toward bad wheel bearing.

I'm still unclear on how much grease is used when replacing the 2 bearings and why the amount of grease (as long as there is enough) is critical.

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You can't always get what you want, but if you try sometime you just might find you get what you need.

Remove the center cap cover and pack in as much grease as you can then see if the noise goes away. You also need to adjust the pre load on the bearings.

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CENSORED due to not family friendly words

about a total of 65 grams in the bearings and hubs and about 15 grams in the cap (till the ridge line in it)

use any wheel bearing grease for disc brakes (the pack should have the GC-LB logo on it)

I personally find Penzzoil 707 and mystik Jt6 from orielly to be really good for this purpose. You can also choose to buy the 10 dollar toothpaste pack of grease from MB, its the green stuff that the factory uses.

Bearings are cheap and plenty, go to an Autozone/advanced/napa etc. they would have them. I was looking for the seals and NAPA stocked them but their clerks could not locate them, I made a thread for it.

http://www.peachparts.com/shopforum/diesel-discussion/328049-front-wheel-bearing-seals-availability.html

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

If you drive with noisy bearings you will have to buy a new hub an spindle if the bearing welds itself.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

If you change a front bearing do not put in a Chinese one. Make sure of the country of origin. I have been using the same methology on front wheel bearings for 55 years now.

Pack the bearing either using a packing tool or two hands. You want to drive the grease into intimate contact with all the surfaces inside the bearing. Install the bearing and add a little more grease. Use high temperature bearing grease on rotors.

Jack the wheel off the ground. If any play is noticeably evident the bearings are worn or the races are. Second test is to place a finger near the wheel on the chassis suspension. Spin the wheel slowly. Do you feel a vibration?

If either condition is experienced I will change the bearings and their races out. After changing the bearings and races I drive the car and recheck the end clearances. Just to verify that the new races did not further seat themselves a little better under operational load.

^^ As said above, it pays to install good quality bearings, NTN, Timken, FAG, SKF are great - provided they are genuine.

To set the clearance, MB tell you to use a dial gauge, you can "fordchevy" it too - just make sure you account for the finethreads of the spindle and the clamp nut can be set anywhere unlike the castle nut. I personally have found the use of a screwdriver to tighten the nut as the best tool - that way you dont apply too much torque.

You also get to see where the bearings get to zero clearance. Back off a bit (1cm measured at the periphery of the hub snout.

If you own a dial gauge then great - enjoy the finesse of setting it like MB wanted.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Proper bearing packing method:
Correct way to pack a wheel bearing - YouTube
I usually will pack the bearings as shown, then scoop some grease out of the tub and smear it inside the hub. About twice the amount used to pack the inner bearing seems to work well. A good glob of it in the cap helps too. The reason for a spec is that if you fill the cavity, there is no place for the grease to expand to except past the seal or pop the cap off. Either way at best causes a mess and at worst can let dirt in.
Gloves are a nice thing when doing this too-
The quick and dirty way to set the bearings up is to tighten the nut (gently) while spinning the hub until you feel the increased resistance, then back off about a flat, maybe two since these have a pretty fine thread. If it spins nice and free without excess play, you're all set.
I did have a bearing failure a couple weeks back that spun the race in the hub ($80) and also marked up the spindle ($150 if it was just a little deeper). This was just a rumble, it never got really bad or gave any signs the s was about to hit the fan. I had gotten the bearings to do the job the week before, but had put nearly 2000miles on the truck in the interim. So, take care of your issue promptly before it costs you more.

Is the amount of grease really this simple? From my readings, several folks made such a huge issue about it and I couldn't understand the logic.

I've greased my share of wheel bearings and recently learned a trick. Use a large ziploc freezer bag and put some grease and the bearing inside. You can load the bearing with grease with your hands clean on the outside. Remove the bearing and seal the bag and the remaining grease is there for the next bearing.

I don't have a dial guage but found this link showing an alternative method to properly tighten the lock nut. Front Wheel Bearings: A step by step pictorial - Page 2 - Benzworld.org - Mercedes-Benz Discussion Forum

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You can't always get what you want, but if you try sometime you just might find you get what you need.

as said the amount of grease is not very critical, you can even pack 70 or 90 grams in there and still have some space, its just to allow the grease to expand and also walk as the hub spins.

the hub is spindle shaped and will fling the grease outwards when the hub spins, this causes the grease to be forced into the bearing races keeping them lubricated. This is also the reason I like soft flowy greases in the hub. When I last removed the hubs (ball joint repair) I saw the grease had backed up towards the bearings. In my mind it sort of proved that the centrifuge concepts really works.

A freind of mine has a mazda RX7 - its hubs are also similar, just more finely machined. He made the mistake of packing it full. It caused the grease seal to leak.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)