Wheel bearing preload

Katy,
That is a good way to put it. I was taught that as you tighten to snug, you feel a soft zone, then a firm zone, then tight. This all happens in the last half a turn. You want to be in the firm zone toward the tight end but never TIGHT. Your explanation is much more concise.
In other words, just use feel.
 
I tighten them up first to make sure the bearings are seated then back off the nut. I then snug them up and back off one position on the cotter key. Ford said to snug then back off one position. The drums should be free to turn without drag but no perceptible play. Remember to put the cotter key in. I don't think it would hurt the bearing to be slightly snug but they should not be tight nor loose.
 
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NO PRELOAD !!! . I snug the spindle nut up so I am sure all is well seated, .I fit a wheel with no hubcap grasp the wheel at 6 o clock and 12 o clock and adjust so I have just perceptible rock it it easy to tell bearing rock from kingpin wear . I have a box of axle nuts so I can choose the best fitting one . On a UK club tour a car pulled over as steering and braking stability was lost . The right front hub was smoking and the wheel at a wonky angle .The owner had completed a pre tour check around ,lug nuts etc etc . He found he could move the spindle nut by hand until it came up to the cotter key . He thought this cannot be right so he torqued it up tight , luckily he did not do both sides .The outer wheel bearing had disintegrated and set the grease on fire . The inner race was seized to the spindle and was freed by hefty bops with a big hammer backed up with another hammer . Luckily the spindle after a quick dress was good to go and a new wheel bearing plus grease was donated by another member on the tour (you never know when you might need one !!!) The big inner bearing was changed as well . The escaped rollers were retrieved from the hub and after an hours delay we were back on the road . The only other break down was a repro clutch arm which broke so that went home by Haggerty .

John in sunny afternoon Suffolk County England .

In England a cotter key is a split pin and an English Muffin is a Muffin .
 
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I have always taken the advice of a good mechanic many years ago that has served me well . Tighten the nut up tight to make sure bearing races are positioned, then back off and bring back to snug. With a large screwdriver, pry the washer that is under the nut and adjust the nut until the washer can be moved with just a little force. New bearings can be adjusted a little more snug than used bearings. Hope this helps.
 
I read somewhere that the pre-load for the front wheel bearings should be set at ten inch pounds. I tried to do that one time with an inch pound dial indicator wrench and I thought it was too tight. Tapered roller bearings in the differential are set at twenty inch pounds, but they are running in oil, the wheel bearings are running only in grease. Like most comments above I set it by feel.

If they are set too tight heat will build up on a long high speed drive and it could easily shear the spindle off. I saw it happen one time.

Tom Endy
 
Here's the technique I use:
 

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Bob, is it necessary for me to paint a red arrow on my brake drum as you have done?

I am not sure but that seems like just way too much work. Plus your diagram does not show if it should be always painted at the same location:D:D:D:D
 
Bob, is it necessary for me to paint a red arrow on my brake drum as you have done?

I am not sure but that seems like just way too much work. Plus your diagram does not show if it should be always painted at the same location. It appears that the red arrow must locate where the cotter pin is inserted.:D:D:D:D
 
These are all good comments. I do like the red arrows Bob. For me, I don't want the bearings snugged up and I don't want any play in the bearing. Most often after you seat the bearing with a light load, back off the nut 1/4 turn then hand tighten back till it stops, then advance to the next available slot for the cotter pin, you will be good to go. Insert the cotter pin and feel for any loose motion in the bearing. If any, no good. Ed
 
The slide is part of a presentation and the red arrows are animated to fly-in with certain parts of the text. But you-all get a bonus to see red arrows all at once.;););)
 

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l.bacon said it best. Tighten very snug to set bearing, then back-off and retighten until snug BUT YOU CAN STILL SLIDE THE FLAT WASHER WITH A SMALL SCREWDRIVER. Have used this method on all wheel bearings for over 60 years with no problems.
 
Isn’t there only the hardened retaining washer with the tab to keep it from spinning behind the spindle nut? I don’t see any other washer?
 
Oldgearz said:
l.bacon said it best. Tighten very snug to set bearing, then back-off and retighten until snug BUT YOU CAN STILL SLIDE THE FLAT WASHER WITH A SMALL SCREWDRIVER. Have used this method on all wheel bearings for over 60 years with no problems.
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This is all you need to know to prevent having the preload too tight, period.
 
There is no preload on the wheel bearings! There should be some play to allow for thermal expansion. Preloading the bearings increases the normal force which increases the bearings kinetic friction and yielding excessive heat.
 
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