SIDE NOTE: The mechanic used the blunt chisel method to tighten the lock nuts. He says he does this because using a socket tends to shear the keyway "tit" off the star/lock ring. To be honest, I'd probably prefer to use a toirquewrench and socket instead of a chisel because I do tend to believe that the lock nut has to be degraded by this method over time. BUT I'm no expert!! & I CERTAINLY didn't want to tell him how to do his job! (I felt I was ALREADY on the verge of doing that with the regrease & re-preload requests!) Nice guy! He was pretty receptive to my suggestions and put a lot of extra hours in on this job! But I did back up my suggestions with either a Maintenance Spec or a SteelSoldiiers reference!! So that gave me SOME additional credabiliity!
I don't know what kind of mechanic you went to, but NO truck mechanic especially a certified one would ever use a chisel to tighten a wheel nut !!! That is total
bullcr@p what he said about the tang breaking off.
Also, most heavy trucks have around .002" endplay on the wheels when cold. Due to the mass of the rotating assembly, it can really get hot, and when metal gets hot it expands. If the wheel bearings where adjusted with no play when it was cold, then after the bearings get warm from driving you would have a negative endplay, meaning the bearings are too tight !!! Causing even more heat! All the axle manufactures have a bearing preload procedure, which when done right will have endplay, usually around .002". At our shop at the transit agency, we had a new mechanic adjust the wheel bearings like a car, no endplay. After 4 hours on the road, the buss came back with all the oil in the hub blown out all over the wheel. It was so hot, you could not even touch the tire rims ! Remember guys, this is a medium truck not a car or pick-up ! I know this is an old thread, but when I read that statement about the mechanic tightening that jam nut like that, I got so mad, I could hardly see straight ! It makes the rest of us Professional mechanics look like fools. I had a full year of trade school, 4 years of apprenticeship, and at least 2 weeks of special training EVERY year to keep up with changing technology since becoming a journeyman mechanic. Nowadays I guess anyone can call themselves a mechanic if they changed a spark plug !