190e Wheel Bearing Question
 

I got this one done this weekend. I tightened the nut down by hand very tight, but could still freely turn the hub. The washer was locked. I backed it out a bit until the washer turned freely but with some resistance. I could not get any play in the hub in/out or side to side.

I put the rotor on and attached the magnetic part on the rotor and the dial on the nut. Wiggling back and forth I got readings of 1mm of travel. By feel only there was no play at all. With the wheel on there is still no in/out travel but some back and forth travel.

Tightening by hand does not allow me to "lock" the hub/rotor. Should I be cranking that nut with channel locks or something?

Even a little too tight will ruin a bearing in no time flat. They will run near forever when set on the loose side.

The rotor can turn alomg no problem. The nut sits on the threaded spindle, which is fixed.

I use the "can just start to slide the washer" method all the time and have always been happy with it.

If you mounted the stand on the rotor face - did you lock down the rotor to the hub? it takes a spacer and a lug bolt to lock it down, otherwise all readings are off.

I personally like the advance by hand method and the correct quantity of good ol' american wheel bearin' grease fer them new fangled disc brakes

I didn't bolt the rotor down other than the small set screw. So that probably explains the high reading then. I'm going to recheck in a few days and try locking the rotor with lugs.

I drove it in to work today and it drove fine. I think my steering rattle is finally gone.

The end play spec is 4-8 ten-thousands, which is very difficult to actually measure and much smaller and narrower of range than the 1-5 thousanths typical of my vintage Corvette and Cosworth Vega.

The nice thing is that infinitesimally adjustable pinch bolt nut. On a vintage Chevy you have a 20 thread per inch castle nut with two perpendicular cotter pin holes, so the nut has to be turned in 1/12 turn increments, which changes clearance by about .004".

Bolt down the rotor and tighten the spindle nut to a few lb-ft torque and spin the rotor a few times. Then loosen the nut just to the point where you can barely feel play by wiggling the rotor sideways and tighten the pinch bolt to lock the nut to the spindle.

You may want to do the above several times until you get a feel for when you can barely detect play.

Do a final check with the wheel installed.

As a general rule the smaller the wheel bearing end play, the more precise the steering wheel will feel. On my vintage GM cars I dressed down the washer a few thou so I could get the end play into the 1-1.5 thou range, by turning the nut an additional 1/12th turn.

Duke

if you dont bolt the rotor down with atleast 2 screws the rotor will flex as you pull on it.

put a lug bolt across from the set screw and tighten it down.