Mercedes W203 front wheel bearing play

[amazighman]

I would have to remove the wheel , then tighten the clamp bolt....
I think if that works , it will make the job simpler ,

 

[OneForTheRoad]

Put 2 wheel bolts in the hub and use a long screw driver to lever against , might save you some time .

 

[Petrol Pete]

There is a video on you tube of a guy (Russian/Eastern European) with a unique way of doing this , He adjusts the locking part slightly, re mounts the road wheel , spins it while hitting the tyre with a big rubber mallet. Repeats until he is happy.

Works for him !!

 

[IanW]

My preference was to put just the brake disc back on using the wheel bolts + spacers (20mm lengths of 12mm copper pipe), nipped up tight enough to hold the disk securely against the hub. This gives enough flat metal for the magnetic clamp on the dial gauge to stick securely. Then measure the end float on the bearing by pulling/pushing the brake disc (NOT rocking the disk) and reading the dial gauge.
As mentioned above, the tolerance is 0.01 to 0.02 mm - around a quarter the diameter of a human hair!! - and corresponds to less than 10 degrees of turn on the locking nut. It's very easy to nudge the nut round a few degrees while tightening the tiny Allen headed bolt in the nut.
The process takes quite a while to get right - in my case complicated by the bearing being damaged, so I was unable to get a sensible setting until I replaced the bearing & repeated the operation. 30K miles later & so far, so good.
Ian.

 

[Petrol Pete]

Ian, you are over thinking it, it's a mass produced adjustable wheel bearing on a mass produced car, 0.01 - 0.02 is what some call a 'Bull$hit measurement' . When manufacturers write maintenance manuals and can not write ...'adjust until it just until it stops wiggling' so they put in a measurement.....usually bull$hit.

 

[190]

it's a mass produced adjustable wheel bearing on a mass produced car, 0.01 - 0.02 is what some call a 'Bull$hit measurement' . When manufacturers write maintenance manuals and can not write ...'adjust until it just until it stops wiggling' so they put in a measurement.....usually bull$hit.

I've often thought that manufacturers specify end play because it possible to measure it while pre-load is very difficult to measure. In fact the optimum bearing life is just marginally better with a tad of pre-load. I have a wheel bearing application where pre-load is specified as the correct setting in terms of rotational torque to overcome the friction of the pre-loaded bearing. What I take from this is that as close to zero end play as can be achieved is the optimum practical setting and I'm dubious about the thermal expansion reason for end play being specified. Too much pre-load is obviously a problem as shown by the steepness of the curve

 

[amazighman]

I got fed up with the dial gauge , its all over the place ,
Went and tightened the nut gradually with wheel on untill very minimal play is evident and the wheel still rotates freely , Wheel off and tightened clamp bolt... If it lasts then ok... If it fails then a second hand spindle from Breakers.

 

[190]

It'll be fine.

Timken's web site has another graph which I didn't post because it was too complicated and makes no sense without reading a full page of accompanying text. What it does show in simple terms is that the optimum band of settings is anywhere between 0.04 mm end play and 0.04 mm pre-load. MB's spec is well within that but you are up against it trying to measure 0.01 mm with a dial gauge. That's less than half a thou in old money.

 

[Petrol Pete]

Like I said...Bull$hit measurements , engineering is full of them. Just because you can measure something to the widths of a Gnat's c0ck doesn't mean that you have to.

 

[LabourOLove]

My preference was to put just the brake disc back on using the wheel bolts + spacers (20mm lengths of 12mm copper pipe), nipped up tight enough to hold the disk securely against the hub. This gives enough flat metal for the magnetic clamp on the dial gauge to stick securely. Then measure the end float on the bearing by pulling/pushing the brake disc (NOT rocking the disk) and reading the dial gauge.
As mentioned above, the tolerance is 0.01 to 0.02 mm - around a quarter the diameter of a human hair!! - and corresponds to less than 10 degrees of turn on the locking nut. It's very easy to nudge the nut round a few degrees while tightening the tiny Allen headed bolt in the nut.
The process takes quite a while to get right - in my case complicated by the bearing being damaged, so I was unable to get a sensible setting until I replaced the bearing & repeated the operation. 30K miles later & so far, so good.
Ian.

This is exactly how it tells you to do it in the workshop manual. I did both sides of mine using this method.

 

[amazighman]

Did the same , however my dial gauge from fleabay cant be correct.
I get 0.1 play , then there is too much excessive play when wheel was put back on.... And My hands are aching from pushing pulling the bloody disc.

The disc never locked or was hard to move by hand when I tightened the nut and there is still a small bit of play left , so It cant be over tightened , I would say the initial play was reduced by 80 percent

I believe most fast fit garages and small mechanics dont use any gauges , And yet millions of cars on UK roads still doing ok.

 

[LabourOLove]

Did the same , however my dial gauge from fleabay cant be correct.
I get 0.1 play , then there is too much excessive play when wheel was put back on.... And My hands are aching from pushing pulling the bloody disc.

The disc never locked or was hard to move by hand when I tightened the nut and there is still a small bit of play left , so It cant be over tightened , I would say the initial play was reduced by 80 percent

I believe most fast fit garages and small mechanics dont use any gauges , And yet millions of cars on UK roads still doing ok.

Have you inspected the spindle for wear?

 

[amazighman]

No. I didn't even strip the things down , only nipped up the nut.
There might be some damage somewhere , as when I bought the car it had warped discs , some muppet put em on without cleaning the hub . I dont know how long he run it like that , but first thing I did when I got it is fit new discs and pads.
I ll have to keep an eye , If the problem gets worse then I ll source a second hand spindle

 

[219]

I thought that when you bolt on the road wheel there should be no play whatsoever....

The wheel is bolted to the hub ; the hub is mounted to the stub axle by the wheel bearing .

 

[219]

I have no specific experience of a W203 but MB's don't usually have castellated nuts with discrete locking positions, they have a split nut which is clamped onto the thread at any chosen position. It's much superior and MB have used it for 30 years or more.

Some of mine have had castellated nuts , certainly the rear bearings on my 190E used them because I changed the diff on that car , as did the rears on my R129 and W140 , on which I worked very recently . I don't recall the fronts as I never had the grease caps off .

 

[amazighman]

I decided to take the outer bearings out , clean and repack with MB spec green grease ( febi) , I tightened the clamp nut with wheel on untill there is a very minute amount of play , Tightened the little bolt, and put everything together.
Spin the wheel , spins ok.... Either job well done or I will be in the market for some bearing soon.
Dial gauge was useless...guess cheap chinese ones aren't up to job.

 

[amazighman]

Went for 4 mile drive , car felt like dragging , pulled at a supermarket and checked both wheels , passenger cool as cucumber , driver starting to warm up.
Took it back home and loosened the bearing nut and got just a tiny bit of play , hopefully will be ok

 

[JOHNO978]

I decided to take the outer bearings out , clean and repack with MB spec green grease ( febi) , I tightened the clamp nut with wheel on untill there is a very minute amount of play , Tightened the little bolt, and put everything together.
Spin the wheel , spins ok.... Either job well done or I will be in the market for some bearing soon.
Dial gauge was useless...guess cheap chinese ones aren't up to job.

I shall be doing my front bearings in a few weeks time, W203, I did mine on my W202...The procedure is the same...I tightened the main nut by hand while I was turning the hub..until I felt a drag on the hub so much so I couldnt spin it by hand..I then did what my Dad taught me as a youngster he was a mechanic....I turned the nut back by one flat...I then gave the end of the spindle a few light taps to settle the bearing. Then undid the nut...then retightened it by hand until I could feel a bit of drag while I was turning the hub...it took me a few attempts until I felt it was right..a bit too tight..a bit too slack..then I found what I was happy with..I then spun the locking bolt up..again by hand..fastened the allen bolt to the recommended torque and that was it...I had renewed the complete suspension so checks would be done in a week or so..I checked the bearing and it was fine....I would advise that you get a manual for your Car...if nothing else they do point you in the right direction...the one I have for my w203 is very vague as it seems to cover the Estate and Diesel version..but it comes in handy...Im sure that If I am out in any way I shall be rightly corrected...

 

[amazighman]

I shall be doing my front bearings in a few weeks time, W203, I did mine on my W202...The procedure is the same...I tightened the main nut by hand while I was turning the hub..until I felt a drag on the hub so much so I couldnt spin it by hand..I then did what my Dad taught me as a youngster he was a mechanic....I turned the nut back by one flat...I then gave the end of the spindle a few light taps to settle the bearing. Then undid the nut...then retightened it by hand until I could feel a bit of drag while I was turning the hub...it took me a few attempts until I felt it was right..a bit too tight..a bit too slack..then I found what I was happy with..I then spun the locking bolt up..again by hand..fastened the allen bolt to the recommended torque and that was it...I had renewed the complete suspension so checks would be done in a week or so..I checked the bearing and it was fine....I would advise that you get a manual for your Car...if nothing else they do point you in the right direction...the one I have for my w203 is very vague as it seems to cover the Estate and Diesel version..but it comes in handy...Im sure that If I am out in any way I shall be rightly corrected...

I have access to WIS , one should use a dial gauge but mine is kaput.
The ideal scenario on these bearings is to tighten that nut very very gradually , checking for play , Untill there is very very little play and no drag then tighten the clamping bolt , The problem with these is you tend to lose the adjustment as you tighten the clamping bolt , big nut tends to move a bit... Guess it's a lots of trial and error till you get it right

 

[JOHNO978]

I have access to WIS , one should use a dial gauge but mine is kaput.
The ideal scenario on these bearings is to tighten that nut very very gradually , checking for play , Untill there is very very little play and no drag then tighten the clamping bolt , The problem with these is you tend to lose the adjustment as you tighten the clamping bolt , big nut tends to move a bit... Guess it's a lots of trial and error till you get it right

Well all I can say is that 10yrs later those wheel bearings are working as they should...you can dial whatever you wish into anything...but the feel will always prevail....and I shall install my new bearings in the exact same way as I have done for years...I was just trying to help..but there you go...