Front Wheel Bearings - tightness?

Earle

Earle

Senior Member
I'd appreciate some thoughts and expert input from the Gang: I'm wrapping up my list of "periodic service" and maintenance items in getting the roadster ready for spring. I always remove the wheels and drums to inspect and vacuum out the brakes, repack the bearings and add a trace of hi-temp grease on the wedge and rollers. But how tight should the spindle nut be when reinstalling the drums? It's all a matter of how much "preload"or looseness" should be put on the bearings.

I have driven for years on the premise that you never want to "over-tighten" bearings because it squeezes out all the grease as the roller runs on the race, over-loads the bearing and accelertaes over-heating and failure. Overly-loose bearings also fail early from allowing the rollers to lift off the race and undergo cocked, high "point-loading" on the race instead of the intended "line rolling Contact loading". Both lines of reasoning are logical. BUT between "over-tight" and "over-loose" there's a lot of dangerous wiggle room.

Sooooo...I have always hand-tightened the spindle nut while slowly spinning the wheel. Then when it's hand-snug, back off to the nearest castle slot for inserting the cotter pin. Of course you can then sometimes feel a tiny bit of wiggle in the wheel when it's re-installed. I've known others who tighten the nut to the next nut slot - or even an extra slot further!

Here's what got me confused. After getting my car back from Schwalm's recently for some brake work, I found that their mechanic had tightened the spindle nuts so much that I needed a wrench and considerable effort to loosen them. When up on jack stands, the wheels would quickly come to a stop when I tried to give them a good spin by hand. Since Ora's crew are good mechanics, this worried me some and got me thinking about it. What would have happened if I had kept driving it in that extreme condition?! When I called Ora about it, he agreed that was too tight but he does like "tightness" rather than any looseness at all.

We can't talk in terms of a specific nut torque because castel nuts don't allow it - and only a tiny turn of the nut is the difference between tight and loose.

Thoughts?
 
I think I would call Schwalm's and talk to them about this..
I believe in a little clearance.. I tighten them pretty snug and then back off for just slight clearance.. If I end up between slots I'll try another nut or have even ground/sanded a bit from the nut.. The grinding/sanding is going too far,but, it makes me feel good..
 
Earle,

I always do my front wheel bearings like the way you do.;) The slight
"wiggle" you feel in your wheel after putting it back on could be a looseness in your kingpins!?!:eek: Which dosen't neccessarily mean you
need to rebuild them. Especially if you don't have any "shimmy" in the
front end when you hit a bump. But, keep it in the back of your mind
for when the driving season is over to check things out.:)

AMF/Bob-A:D
 
It's possible the drag you felt was from the brake work?? I'd do it the way you've been doing it and then reck in 4 or 500 miles. JMO
Paul in CT
 
i tighten the nut untill its pretty tight , then back off untill its loose again , just barely , then tighten just a little to get the key in . probably alot like you do . tight bearings are not good .............. steve
 
Tighten with a wrench while turning to seat and settle bearings, then back off, tighten as much as you can with 2 fingers, back off to nearest pin hole alignment.

There should not be any preload on the bearings ---if there is eventually the bearings will make their own clearance ---and you won't like how they do it. ---a taper roller bearing in a differential can have some preload, but it also runs in a oil bath.

Using the 2 finger method only works properly if the nut turns on the threads smoothly.
Most of the wheel bearings I replace on the Mercedes I work on at my job have been recently worked on and were overtightened, a Mercedes has infinite adjustment, and calls for .001 end play yet I find many that were tightened with a wrench to the point of binding the bearings -----replacing spindles and hubs pays good
 
Earle,
Go on search, we had a lengthy discussion on bearing packing and "pre- loading" bearings.
Modern car bearings are the same design and similar size as Model A's and I feel that their pre- load specs ARE applicable. I always torque them to 100 inch lbs,(10 ft lbs) and it has always worked for me. I ALWAYS USE A QUALITY BRAND,HIGH TEMP DISC BRAKE GREASE. There's a lot of cheap "Poo Poo" greases out "there," Bill W's Ghost
 
Thanks, Gents. 'Looks like we "just barely loose" guys are out-numbering the "slightly tight" guys.

1931 flamingo - The tightness was not the brakes dragging. There was no dragging sound and, as soon as I loosened the spindle nut, the wheels immediately freed up and spun freely. What did you mean by "...and then reck (wreck?) in 4 or 500 miles." ?

Bob-A: Thanks for the thought but my king pins are tight. I know it's all in the looseness of the bearings when I grab the outer edge of the wheel and wiggle it (because it goes away when I tighten the nut more.). But it's very slight after I've managed to get "just the right amount" of clearance when inserting the cotter pin.

So that's the way I'll keep doing it, I reckon. In twenty five years of doing it this way I've never had a bearing failure or have one show visible signs of abuse. If Mercedes Benz (per Kurt) calls for 0.001 end play, I guess we "loose" guys are in good company.

Hey, Patrick L. : I have been known to grind a smidgeon from the face of the nut too. So don't be ashamed!
 
For 40 years I've been adjusting all wheel bearings on all my cars the finger tight then back off one slot method, and I've never had a wheel bearing fail nor even wear out. Sometimes I'll wrench tighten first to make sure everything is seated, then back off using the wrench and repeat the finger tight technique. The one time I had a wheel bearing fail was when a tire jockey at a Firestone store preloaded the bearing. I questioned him about it as he was doing it, he assured me that I had been doing it incorrectly my whole life. The bearing proceeded to go down in flames a couple of hundred miles later. I decided it would be inadvisable to change my method.
 
On those small tent trailer wheels,most brg failures are caused by being too tight.They need more than normal looseness or they will fail.
 
The Ford Service Bulletins, page 203, recommend tightening the spindle nut until the hub just starts to bind. Then back off the spindle nut one or two notches and insert the cotter key. Using this method you should have no end play and the wheel should spin without any binding.
 
I have always tighgtened and then backed off, as most. A few years ago, I had left them too loose and this led to trouble. So I now tighten with a wrench and back off. I Then finger tighten it as far as I can and back off to the next slot. I once burned out a bearing by having it too tight. With this method, I don't have looseness or burn anything out. works for me!
Terry
 
Hi Earle,

For what it is worth, I called & asked for a Timken manufacturing technical engineer about 10 years ago & requested information on tightening Model A Ford front wheel bearings.

When checking similar front wheel bearings, he responded that:

1. The recommended end play after tightening the nut & inserting the pin should always be approximately seven-thousandths of an inch, (.007") after providing new bearings & also for re-installing bearings which have already been in use.

2. If front wheel conical bearings are tightened too tightly, with absolutely no end play, the bearing races, (cups), could begin turning inside the hubs until they become worn, thus ruining the hub; & also bearing centers could begin rotating on the axle, thus ruining the axle.

3. The bearing races, (cups), should always have an interference fit in the hub without the bearing races fitting loosely & spinning freely. The bearings placed on the axle should also always have an interference fit on the axle without the bearing fitting loosely & spinning freely on the axle.

4. One should always grease out-sides of bearing races & insides of hubs prior to installing bearing races in hubs; & one should always grease the out-sides of front axles & cylindrical in-sides of conical bearings.

5. On occasion, with stress while turning, or upon impact of hitting something similar to a pot hole, the bearing race & bearing may rotate ever so slightly as opposed to remaining fixed; however, if lubricated, the joint between the out-side of the bearing race & inside of hub, & the joint between the bearing & the axle will not wear as much as if this joint were installed dry with metal to metal movement.
 
You must log in or register to reply here.
Back
Top