MGB MGB Wheel Bearing Video

[DrEntropy]

I'll pass. Already have a background in the metallurgy and mechanics of it. Spent a few years as an NDT inspector making certain that John Timkin got the proper tubing materials to make his races (pardon th' pun /bcforum/images/%%GRAEMLIN_URL%%/wink.gif ). NDH was a 'customer' too. Electric Boat got nuke-grade stuff from us to make the cooling apparatus for their small reactors. I'm plenty T.O.'d.

All I need to know is that my wheels' bearings have never ground themselves to uselessness and never (knock wood) had a stub-axle failure due to missing shims n' spacers in the fleet of MGBs I've worked on...

"That is all."

...but thanks fer th' tip.

 

[DrEntropy]

So I guess that means only a 6-pack and you just don't make fun of me in public? \:G

If it's reciprocal: DEAL!


...I'm sooo ~easy~... and a cheap date, too. /bcforum/images/%%GRAEMLIN_URL%%/smirk.gif

 

[tony barnhill]

I believe that with or without the shims, the outer strengthening sleeve (if that's what it is) is in place & doing what its supposed to so long as all the other components are touching & tight enough that there's no play outside acceptable parameters.

Strengthening the spindle is the primary purpose of the shims.

Is it? Or is their primary purpose to keep the bearings from being squashed so tightly that they don't allow the hub to turn on them when torque is applied?

I still want to know if anybody knows of an MGB stub axle ever breaking?

 

[Steve_S]

I believe that with or without the shims, the outer strengthening sleeve (if that's what it is) is in place & doing what its supposed to so long as all the other components are touching & tight enough that there's no play outside acceptable parameters.

Absolutely. But they aren't in contact and under pressure without shims unless you're VERY lucky on the spacer length. That's why the shims are there - to set the spacer distance between bearings to allow the "outer sleeve" to function without smashing down on the bearings.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]...is their primary purpose to keep the bearings from being squashed so tightly that they don't allow the hub to turn on them?[/QUOTE]
Yes, both reasons are linked. The outer sleeve cannot function unless under tension. Putting tension on the assembly with too short a spacer will crush the bearings. The shims allow for the proper bearing end float and the proper tension on the stiffening assembly, as well as the proper nut torque, all simultaneously.

Leaving the shims out usually allows for only one of the three at best. You would try to get the end float as close as possible, but it still won't be right on because you can't leave the nut where the end float is correct since the hole will never line up.

 

[tony barnhill]

The shims allow for the proper bearing end float and the proper tension on the stiffening assembly, as well as the proper nut torque, all simultaneously.

Leaving the shims out usually allows for only one of the three at best.

Good explanation. So, shims allow for:
1. Proper bearing end float
2. Proper tension on the stiffening assembly
3. Proper nut torque

I agree....& the method described in the tech tip on my web site allows for the first 2 items (proper bearing end float & proper tensioning on the stiffening assembly) without requiring the third (proper nut torque).....thus, when 'float' is minimized by 'feel' rather than 'torque', one can always ensure the cotter pin hole aligns.

When I get home, I'm gonna do something just for the heck of it: My '74-1/2 GT is still in the air...I had just rebuilt everything using the 'non-shim' method before I came to New York...I know everything is set correctly & the float is proper; so, I'm gonna pull the cotter pin & check the tightness of the nut with my torque wrench...wonder how close to 60lbs it'll be?

 

[Steve_S]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]...the method described in the tech tip on my web site allows for the first 2 items (proper bearing end float & proper tensioning on the stiffening assembly)[/QUOTE]
The only way to get both the end float correct and the tension on the "outer spindle" correct is if the spacing between the bearings is exactly right. The only way to achieve this is with a spacer made exactly the right length, which is extremely unlikely, or with the use of shims to make it the right length.

With a standard spacer (which is made short to allow the use of shims to fine tune) and NO shims, you cannot achieve proper tension without mashing down on the bearings. So you back off to take the pressure off the bearings and no longer have tension. It's one or the other.

Nut torque is the last in line. Even with shims in place on the spacer, you can get the torque wrong on the nut the same way you get it wrong by leaving shims out and using the "tighten then loosen to pin hole" method. That's where sanding down the nut a little comes into play.

 

[tony barnhill]

I hear what you're saying...but I also know that after you torque the nut, you sometimes have to add or subtract from the torque (even after playing with shim combinations)to get the cotter pin to align (or sand the back of the nut??) & that action aleviates the importance of torque.

Are we having fun yet?

 

[Steve_S]

The importance of torque is to put the proper tension on the "outer spindle". (I keep envisioning Dr. Evil doing the quote thing with his fingers and saying "lasers" every time I type that) The shims adjust the spacing so the bearings are properly adjusted for end float when that torque is attained.

Shims are better than no shims dangit! LOL! You and I argue a point the same way. No one will ever win no matter who is right. /bcforum/images/%%GRAEMLIN_URL%%/crazyeyes.gif /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

 

[tony barnhill]

No one will ever win no matter who is right.

Yeah, but ain't it fun!!!

 

[Steve_S]

No matter what you do, if you aren't having fun then there's no point. But I must admit that I would be having more fun driving my car than discussing how hub shims strengthen spindles. Unfortunately it's 11PM, I have no radiator in my car and I have to be in Chicago in a few hours. So this will have to do. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

 

[tony barnhill]

Well, its 3:30am & I'm in New York!

 

[1965_MGB]

Keep that keyboard clean Tony.

 

[Baz]

If I may inject a reluctant question.....
I recently put new rotors on, hub removed etc...
I replaced the hub, sans shims because the castellated nut wouldn't line up with the pin hole. Did the nut hand tight until the hub had resistance, then backed off until the hole lined up per forum advice.
Because the excellent discussion prior, has raised great points in both avenues, my question is, is what I have done safe?

 

[Nunyas]

That's how I did my bearings about 2 years ago. It's safe as long as the wheel doesn't wobble around on the spindle. The discussion here is mostly on doing it the factory way or doing it how 99% of the cars on the road have them.

I'm sure if you look at the folks that race their Bs you'll see an equal division in people that use the shims and those that don't.

**EDIT: Actually, now that I think back, I snugged mine up with channel locks and then backed off until the wheel spun freely without slop.

 

[Keoke]

Well, its 3:30am & I'm in New York!

What in the /bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif you doing in NY? we make it too warm for you in Gurley.-----Keoke-- /bcforum/images/%%GRAEMLIN_URL%%/laugh.gif

 

[tony barnhill]

...is what I have done safe?

It's safe as long as the wheel doesn't wobble around on the spindle.

That's my opinion (& lots of other MG owners' opinions also) based on years & years of doing te same thing without any problems

What in the you doing in NY?

Doing one of those training exercises for the Army with the 10th Mountain Division.

 

[1965_MGB]

Have any other threads gone this far? Jeez.

 

[vping]

Sure the "1952 TD reassembly" one. Waiting for Tony to get back so we can make it bigger. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

 

[DrEntropy]

Tony, your hub nut will be nowhere NEAR 60 ft/pound torque. That would bind the bearing without the proper distance tube/shim arrangement. That (as Steve points out) is how the inner races are "pinned" from spinning on the spindle if tolerances are sloppy. With evidence of said spindle abuse a car would get the spacer 'n shims, no question. If the I.D. of the bearings and the O.D. of the spindle are proper, the "no spacer" method will work by Rob's "spin the hub, snug the nut" method.

Again: if it's a customer's car the spacers 'n shims go in. Mine? feh. I'll chance it.

 

[Steve_S]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]I replaced the hub, sans shims because the castellated nut wouldn't line up with the pin hole. Did the nut hand tight until the hub had resistance, then backed off until the hole lined up per forum advice.
Because the excellent discussion prior, has raised great points in both avenues, my question is, is what I have done safe?[/QUOTE]

Probably. But that's a word I don't like to hear when I'm talking about safety, so I take the extra ten minutes per hub to set it up as safely and accurately as possible.