Thanks, TF. So just to verify -- what affects the needle movement if I'm not turning the rotor, the tightening of the axle nut? Didn't see this detail in my version of the shop manual, so huge thanks again.

Start with the indicator slightly preloaded and adjusted to zero. Then pull outward on the rotor/hub, as if attempting to pull the hub off of the axle. Note amount of indicator deflection on the dial. Then adjust the nut to give more or less movement, as required to get the desired .0004-.0008" of deflection.

Note: you are not looking for .004-.008." You want to see the needle move slightly less than one increment (.001) on the gauge.

I totally get it now. Thanks very much!

dial indicator
 

Which dial indicator did you buy, and how much was the cost?

Any chance you might have time to post a pic of it?

Thanks, Dave

I did a wheel bearing on my W124 this weekend - the same tight tolerance applies to the end float or play. I used a mitutoyo gauge;

http://www.mitutoyo.co.uk/MitProd/mtopr.nsf/UNIDS/F255B23AEA15F53A80256953002EAC76!Opendocument

Specifically, the 1013F

However, any gauge that can measure down to 0.01mm should be OK - you shouldn't need to spend a fortune.

Here's mine, a Cen-Tech
 

http://www.chuckwyatt.com/images/cent_tech.jpg

From Harbor Freight, I got the gauge for $15 and the magnetic stand for about $15. I'm done with them, so they are available if someone wants them.

-Chuck

If it worked, keep it for for the 2mm lift for chain stretch and to do the wheel bearings again. They do need periodic servicing.

I use mine frequently, too.

Thanks everyone for the suggestions/comments. New bearings are in. Huge improvement... like BUTTAH!

I have just installed new bearing and seals on my '85 300D. Read this thread afterwards, but it is still interesting and partly mirrors my experiences.

I bought a dial indicator and stand as a kit on sale from Princess Auto (like Harbor Freight) for $16.xx . What surprised me was that the allowed play was less than one division on the dial. (0.0004" to 0.0008"). Moving the nut about 1/8" on circumference changed the reading from zero to the specified amount.

One side stuck on mine too when first putting the hub on - I figured it was just slightly misaligned and gave it a few light blows and it slipped home.

One thing that makes adjustment a bit difficult, is the grease that is everywhere - have to squeeze some of it out of the way when pushing and pulling on the hub.

One other minor thing - I had trouble putting the grease caps back on - There is air trapped and grease around edge makes an air tight seal - the one side kept popping back off! I cleaned grease off inside edge of cap, also gave cap a little squeeze in vice and then pushed it on - stayed this time!

I originally bought bearings and seals from NAPA - Bearings are SKF and fine - BR3 and BR5, I think, But seal they gave me were 50x70x8 instead of 50x70x13.5. (They don't have the thicker ones). Bought proper seals from dealer at a lower price!

Finally a question!

Has anyone checked the end play after driving car for a few days? Thinking it might be an idea if bearings tend to get looser as they wear in.

Hi Graham,

I've not re-checked the end play, but I do think it is not a bad idea at all. I feel like my tracking feels a little more "floaty" so it may be an issue. I had some really loud bearing noise, sounded like an old prop airplane at high altitude flight. The bearing replacement fixed that!

-Chuck

1st post so be kind...

For a Model 123 1985 300D, my CD manual states "Place test instrument (015) on front wheel hub and set dial gauge (022) to approx. 2 mm preload." 2 mm is 0.0787 inches.

So my question is, what am I missing if the freeplay should be .0005 inches?

Did I mention this is my 1st post...

Thanks everyone & this is great site.

i believe a 2mm preload would simply be pushing the indicator towards the hub (so the probe must travel into the indicator) by 2mm or so. This will ensure that the indicator is not at the end of it's travel, and that the lash has been taken out of the gears, etc.

I also had a bearing noise, but not that loud - This is one of my bearing cones (click to enlarge)

x2