[H. L. Chauvin]

Recently witnessed where a few Model A owners in the recent past have become confused with different axle nut tightening & the difference in torque required for the front axle nut & the rear axle nut.

For example:

I. Tapered Front Wheel Bearings:

A. According to Timken Bearing Co., the tapered front wheel bearings should have about .007" clearance between the tapered front roller bearings and the tapered front bearing races as opposed to a tight fit between same.

B. If one tightens the front wheel axle nuts on the front spindles too much, the tapered front roller bearings cease to roll inside the races, & the front bearing races begin to rotate in the hubs, thus wearing out & ruining the front wheel hubs.

II.. Non-tapered Rear Wheel Bearings:

A. The rear wheel bearings are non-tapered roller bearings; hence, these "bearings" do not require to be tightened.

B. However, with the tapered interior of the rear hub fitting on the tapered axle, if one does not properly tighten the rear axle nut to a minimum of 80 foot pounds, there is not enough friction between the tapered axle & the tapered hub; hence:

1) Almost all of the forward or rearward rotational force from the engine is placed solely on the axle key whereby in a short period of time, the axle's key slot becomes wider than the axle key.

2) This axle keyway widening condition gets worse as time goes on while shifting from in reverse to forward, & vice versa, as well as with sudden engine acceleration.

3) Also, both tapers, the one on the axle & the one inside the hub remain loose when not tightened to specifications, & both tapered areas begin to wear with friction such that after time, the rear wheel hubs get loose & begin to wobble.

4) When tapered axles were new, & tapered hubs were new, & when the rear axle nuts were tightened to specifications, there was enough friction generated between these two (2) tight fitting smooth metal surfaces such that very minimum forces were applied to the axle key & axle keyway while the vehicle was in motion.

Hope this helps.