Dial Indicator Measurements For Front Wheel Bearing Question
 

So I read the various posts on the dreaded front wheel bearing adjustments after rotor replacement and decided to purchase a dial indicator and magnetic mount at Harbor Freight. I set up the dial indicator so that the tip just came short of making contact with the wheel spindle end and using the fine adjustment, loaded the indicator to 2 and zeroed out when loaded. I checked clearance on both sides and found that on the passenger side (123 wagon) I was able to move the indicator through 1 line and on the driver side, maybe a half line. The bearings have been fine up to this point (no noises) and the grease did not look/smelled baked. I will try to create these same clearances when I actually pull rotors to replace and repack outer bearings tomorrow but I thought it would be a good idea to get a measurement frame of reference in advance of pulling the rotors given my front wheel bearings have been performing fine without overheating. Any thoughts?

Sounds like a plan. I looked up what MB has to say, 0.01-0.02

You should educate yourself as to what each line represents.
Wheel bearing clearance is not measured in lines.

yes, I know but I read on the forum that getting axial movement through one line was about right. In this case, since my bearings have not been giving me any trouble, I measured in advance of pulling the rotors to see just what kind of play I was dealing with. My dial indicator is set up in inches and will need to see what one line equals -I believe .0001, yes?

Depending on your indicator, but 10 thousandths of an inch is quite small.
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I'm sure MB referred to mm, but it doesn't say.

Depends on the graduations of the dial. That's why you need to educate yourself. Dial indicators are commonly graduated in .001", .0001", .1mm, .01mm. Which do you have?

Forget whatever they are at currently, chances they are incorrect. Just set them .01-.02mm and be done with it. Repack the bearings while you are at it.

The MB spec is indeed specified in millimeters and the dial indicator is almost certainly a .001 inch per division model.

If you convert the specs to inches and assuming he has a .001 inch per division indicator the bearing that measured 'half-line' was pretty close to spec and the 'one-line' side was too loose.

If they were incorrect, I would have had issues with them a long time ago. I have to repack the bearings as I am going to pull the rotors tomorrow for replacement. I think using the existing base line gave me some pretty good information of what to expect in terms of axial movement as it relates to the dial when I reinstall new rotor and repack outer bearings -

Oh, have you driven many 123/126s with overly tight or loose wheel bearings?

.001 -

yea smart ass, I have driven both cars in excess of several hundred thousand miles with zero bearing issues, try being helpful and people will actually pay attention to you

As have I, problem is unless with records most PO's or "shops" have no idea that there is a true spec other than snug... so issues arise.

Of all my 126s I have owned, one was correct. The others still drove fine without issue. No smoke from a hub, no hub falling off on the road, etc.

I was helpful, just reset them properly and motor on. There is very little movement with proper end play, which apparently you know since you have owned and driven all these cars. :rolleyes:

Aim for 60% of one increment and you will be in great shape.

Now we're getting some where. Considering the graduations are .001", what is the play in your wheel bearings and what is the play specified by Benz?