Mike,
By sanding or grinding the back of the nut or washer I am trying to reduce the amount of clearance provided for the bearings when I follow the proper shop manual procedure. At the 55 ft lb torque, the castle nut slot is almost lined up with hole in spindle. Now I back off nut 1/6 of a turn, hole and slot line right up...perfect. No more, no less than manual suggests. With tire and wheel bolted on, and on the ground, I can push and pull the top of the tire and the hubs rock on the bearings. Enough that you can feel and hear the rocking of the hub back and forth. This seems terribly excessive to me. I have adjusted wheel bearings on cars and light trucks many times without failure. This is my first medium duty truck. The procedure leaves way more clearance than I have experienced on lighter vehicles.
My goal by changing the dimensions of the nut or washer is to be able to reduce the distance I back off the nut to less than a sixth of a turn. If I add a washer between the nut and existing washer, I will change the relationship between the castle nut slot and the hole in the spindle when torqued to the 55 ft lbs. This will allow me to back off the nut less than a sixth of a turn to the next slot in the nut. Which would reduce my bearing clearance. This could also be accomplished by sanding the nut or existing washer.
During my first few maiden voyages, I noticed a shimmy in the steering at approximately 45 miles per hour. After inspecting steering and front suspension I came to the conclusion that the rocking of the front hubs was the culprit because I found nothing else wrong. So, its not only my assumption but a mechanical issue that leads me to believe these clearances are excessive.
You have quite a stable of task force trucks there Mike, and experience is everything. Feel free to constructively criticize.
Earlier in this post it was suggested that .005 endplay is correct. I purchased a dial indicator to measure my current clearance before I attempt to make any change.
Thanks, Rich
