Help...! Front Bearing install: what am I doing wrong??
 

So I'm right in the middle of this w/my 300D w123 (1982), popped in the new bearing kit and tapped the seal in place. Lots of grease. Then, I can't get the wheel back full on the spindle. So I try and pull it off.... stuck... pull harder, and it leaves bearing and oil seal behind. Did I pop the bearing in bass-ackwards or is it at least facing the right direction?

Hard to tell from the shop manual. See below!

-Chuck

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

That is the inside bearing, correct?
If so, that is mounted in the hub off the car, and a sealed bearing gets tapped on to hold that one in.
The outside bearing goes on after you've got the hub assembly back on the car, then that spin on split nut, that you need to tighten just right.
Hope this helps.

Chuck,
Tap the bearing from the back side to get it off. Then see if it will fit onto the axle by itself (ie: not installed in the hub.) You may have had the hub somewhat misaligned and the bearing jammed as it tried to go on at an angle.

Exactly.

The fit between the bearing bore and the spindle is very tight..........001" or so. Any foreign material on the spindle.........or any burr.........will prevent the bearing from seating.

I've had the need to polish the spindle with 400 paper to remove the slight bit of surface corrosion to allow the bearing to seat easily.

I'd definitely use some Scotchbrite and/or 400 paper and spend 10 minutes or so to polish it very well.

Thanks Brian and TF! I had installed it into the wheel, off the spindle, but I guess I hadn't tapped the oil seal far enough in. All seems well now! Ready for a test drive.

That is one MESSY job! :rolleyes:

Hmmm... so I did my test run and seems like less noise. I did the passenger front side. Now after the test drive, about 6 miles or so, I touched both front grease caps. The drivers side one is HOT to the touch. Maybe that one needs a re-do as well???

Did you use a dial indicator to adjust the Wheel Bearing clearance/end play?
I thought I could adjust my Front Wheel Bearing by feel as I had done on all of my other vehicles.
I ended up overheating the grease in the hub and haveing to clean out the over heated grease and start again.
I now have a Dial Indicator and Magnetic base to hold it and do the job they way the Factory Manual wants me to.

You only have to use a dial indictor once to realize that there are no good substitutes.

I guess I'm off to get a dial indicator...

I use fine emery cloth tape- from the plumbing dept. to clean spindles. I like to touch up where the seal rides, too.

I also have thought that the dial indicator was not really needed- and have had to replace one set rear and one set front bearings because of this.:o

them German engineers mean business.

Whats this dial indicator business? I've never heard of using a dial indicator for a wheel bearing... or did I miss the joke?

..........you've been sleeping........;)

The dial indicator is used to set bearing clearance. You cannot do it accurately by feel. The specification is .0005" loose.

Make sure the caps are filled w/grease up to the lip of the cap before installing.

OK, so I've got the dial gauge and the magnetic stand for it. What's the process, somehow I mount it on the center of the hub, give a spin and measure (?).

-Chuck

Mount the stand somewhere on the hub/rotor. Dial gauge on the end of the axle. Don't spin anything. Pull on the rotor/hub, adjusting the axle nut until you get just .0005" (actually .0004-.0008") movement on the indicator. (Approx half way between zero and the first index marking.)

In simple terms, you want to adjust the axle nut to allow a very slight amount of axial movement.

It might be interesting to check your original adjustment before you loosen the nut.

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

cooleoboy1000 is probably a spammer. 4/5 of his posts are advertising that site.

What are you talking about? who is cooloboy1000? don`t see him
anywhere in this thread.

Charlie :confused:

He strikes quickly and vanishes without a trace.

Since Tango Fox's remark may not clue you in, you missed him. He was a new member, emphasis on was, and Forced's analysis of his posts was actually kind.

He did post his link to bearing threads, yes, but most of them were drug up from the basement of years ago.

When spammers are removed from forums, their messages tend to go with them. In this case, that's what happened.

Chuck,

I just picked up my dial gauge from Harbor Freight. To check for bearing axial play on a 123, should I applying the gauge on the face of the hub close to the outer edge to measure? It seems to me the location of measurement effects results when testing for axial play. I have attached a photo from the DIY article on changing rear wheel bearings and it appears that the hub was put on without the rotor (??) so that the gauge could be mounted to the dust guard. Wouldn't you have to take the hub off again and attach it to the rotor (and reset the bearing tightness)? There's something I'm missing here.



-Jeb

Rather odd, I did mine as per this link, although its for a w210, the same should apply to our w123's


http://www.benzworld.org/forums/attachments/w210-e-class/140909d1189010683-photo-diy-wheel-bearing-free-play-4.jpg

Thank You for the info on COOLOBOY1000.

Charlie

I know it's way up toward the beginning of the thread, but someone mentioned using Scotch-Brite pads to deburr the spindles.... If you go this route, make sure to clean the spindle afterward! The pads leave small, sharp particles behind, which the bearings don't appreciate very much!