The art of imprecise or approximate engineering
Posted: Fri Sep 23, 2022 9:52 pm
Over the years, I have fitted quite a few sets of taper roller wheel bearings. The relevant manuals have always provided a pre-load torque, a final or running torque and a back-off measurement for the securing nut (eg one flange and align hole for cotter pin, move cap for best fit for pin, or whatever; plus "x" mm play at wheel rim).
I have a small goods or box trailer and two dinghy trailers that, as luck would have it, all had rough bearings at the same time. Whilst the manufacturers were different, all three used the same bearing set. When seeking advice on the correct settings for bearing installation, the only information that I could obtain was: Do up the nut, but not too tight, then back it off a bit and fit the pin. There should be some play in the wheel. I wonder whether whoever produced that guidance would be happy if their payroll team worked to similar guidelines?
I have a small goods or box trailer and two dinghy trailers that, as luck would have it, all had rough bearings at the same time. Whilst the manufacturers were different, all three used the same bearing set. When seeking advice on the correct settings for bearing installation, the only information that I could obtain was: Do up the nut, but not too tight, then back it off a bit and fit the pin. There should be some play in the wheel. I wonder whether whoever produced that guidance would be happy if their payroll team worked to similar guidelines?