Front wheel bearings

[Brinkerhoff]

Bob , I think Donny is talking about the shims on each front wheel being different not on either side of the spacer on one side . It would make no sense to have shims on either side of the spacer.

 

[Bob_Spidell]

Bob , I think Donny is talking about the shims on each front wheel being different not on either side of the spacer on one side . It would make no sense to have shims on either side of the spacer.

It's ambiguous: "???? When I pulled the old one out there were 2 shims on one side and 3 on the other. Is that common? Shouldn't they be the same on both sides?"

Now that I've read that about 10 times I think he means "shouldn't there be the same number of shims on both sides."

AFAIK the shims should be stacked on the outer side of the spacer and, yes, it would not be correct to put shims on both sides of the spacer, but who knows what the DPO was thinking (like, maybe, the shims should be 'balanced').

Maybe Donny can clarify.

 

[elrey]

Another word to the wise. If, after you clean bearings you blow them off with compressed air do so with restraint. Do NOT spin them up to speed, even if they make a cool sound, for if you spin them fast enough they can explode. Mr. learn by doing, --elrey

 

[Donny_L]

Sorry guys, The shims where in the correct place. I meant the diference was from the left wheel and the right one. Also, one of the shims was dammaged. The inside edge of it has a sharp lip on it, as though it had squeezed it's way between the stub axle and the bearing.

 

[Bob_Spidell]

OK, then. To answer the original question, the number of shims doesn't matter. You stack up whatever you need to give the correct endfloat. On my cars it's always been about 0.030" worth of shims. Shims are usually available in 0.003", 0.005", 0.010" and (I think) 0.030". If you need, for instance, 0.029" you'll need 2X 0.010" and 3X 0.003" shims. If you need 0.031" you need 2X 0.010", 1X 0.005" and 2X 0.003".

A slight bend or kink in a shim probably won't hurt, but a stiff 'lip' or edge wouldn't be good.

To do this scientifically (not by feel alone) you'll need a decent micrometer (if only to determine which shims are which).

 

[Brinkerhoff]

The sharp lip on the inside was probably caused by installation as its easy for the shims to hang up on the threads when fitting them into the hub.

 

[Keoke]

Yes Donny, I recognised this and edited my original post.---Keoke-- :laugh:

 

[Donny_L]

I've read the proceedure for this a few more times today in my manual and I'm still unclear on how to make the end float mesurment. Where do I measure? From what to what? and with what tool?

 

[Robert560]

Donny, I'm sure others will have other suggestions, but what I did was use a dial indicator. I bought a decent one for about $100, and it's been invaluable on many occasion for lots of jobs. I'm not sure how you'd do it without one.

What you're measuring is the in-out movement of the hub itself. So you've got to shim it up, install everything, and tighten the nut down. Then you grab the brake rotor (which you should have bolted to the hub) and try to move it in and out. You'd locate the dial indicator on the outer face of the hub. If you've got NO indicated movement at all, and the hub feels tight to turn, then you don't have enough shims. The service manual says to shim way more than what you need, then remove shims until the hub movement is just a couple thousandths of an inch.

I think I started with about .060" worth of shims, so there was lots of slop and lots of in-out movement. Then I read the movement on the dial indicator, re-shimmed to take out almost that amount, then reassembled and checked it again. I think I ended up with 3 or 4 iterations of doing this per side before I got the feel just right. I ended up somewhere around .030" worth of shims... a little more on one side, a little less on the other.

Hope that made sense.

~Bob

 

[Bob_Spidell]

That is the correct, 'official' procedure. However--and this is heresy, I know--I believe you can do this by feel and trial-and-error. Start with 0.030" of shims. If the hub turns tight add a 0.003" shim. If there's excessive end play you know you need somewhere between 0.030" and 0.033" (and you're probably within tolerance already). If it's too loose remove shims. Repeat until the preload feels 'just so.' It helps to have a caliper micrometer to measure shim thickness, but with HF selling decent ones for a few bucks everyone should have one anyway.

I did it with a dial caliper the first time, and think I ended up with too much end play. Even with a dial caliper and a magnetic mount it's difficult to get extremely accurate readings because you have side-to-side play as well as end play (and calipers usually only have +/- 0.001" accuracy anyway).

On all the other--i.e. 'American'--cars I've done this there is no spacer. You adjust bearing preload with the torque on the nut, which 'pinches' the bearings in their races. One technique my dad taught me was to tighten the nut until you could just move the flatwasher side-to-side with a screwdriver without too much effort (kinda like the 'feel' you use when measuring valve rocker clearances). There isn't even an official way to adjust these that I know of; it's totally done by feel.

If you check the back of the Healey shop manual there's a specialized tool for just about every job. How many of us have all the 'official' BM tools? The handiest one for this job is a homemade dust cover puller. I made one by welding a thread coupler to a length of allthread, and using a cut-up bicycle training wheel bracket and a nut and flatwasher. Sure beats tearing up the cover's threads with pliers. FWIW, I believe the bearings on my BJ8 are original--I bought the car with 64K miles and haven't replaced them--and they have almost 170K miles on them now. I even reused the races when I put new hubs on.

As an aside, does anyone think the assemblers at the plant went 'by the book?'

 

[Keoke]

If you've got NO indicated movement at all, and the hub feels tight to turn, then you don't have enough shims. The service manual says to shim way more than what you need,

No it doesn't.The manual says to add shima until the end float is "ZERO" and the hub feels free to turn thats what it means.--Keoke




then remove shims until the hub movement is just a couple thousandths of an inch.

 

[elrey]

I'm with Bob on this one, the screwdriver trick. Haven't had a problem yet, It just takes some experience to gain the " feel ". -- elrey the heretic

 

[Robert560]

If you've got NO indicated movement at all, and the hub feels tight to turn, then you don't have enough shims. The service manual says to shim way more than what you need,

No it doesn't.The manual says to add shima until the end float is "ZERO" and the hub feels free to turn thats what it means.--Keoke

Quoting the manual - Step 4 of reassembly procedure:

"Insert a sufficient thickness of shims to produce an excessive amount of end float." Then is says to measure the end float, remove the number of shims to eliminate end float, etc.

How is that not saying to shim way more than you need, as I said in my explanation? I'm quoting the Healey Workshop Manual... are you looking at something different?

~Bob

 

[Keoke]

How is that not saying to shim way more than you need, as I said in my explanation?--- :laugh:

OK I see what you meant

---------------------------------- :confuse:

 

[oliver88]

On the Porsches the nut is tightened until you can move the washer underneath with just minimal force...That is the 'offical way'...The manual for the 3000 seems to describe a very complex procedure and I suppose I'd follow it...Wheel bearings can be finicky and wear premarturely if it's not set correctly. One other tip...Use a top notch grease...I have raced with Redline CV-2 grease in my wheel bearings and I can see a difference. My old grease would give me a season on a set of bearings...Going on 3 seasons with the same bearings using Redline grease...

 

[elrey]

Always followed the manual, but also always checked them with the screwdriver after spinning the heck out of them just to make sure. Thought that was why they put such slop in the hole in the large keyed washer. Just a hangover from my old chevy habit I guess. --elrey

 

[Randy Forbes]

I've read the proceedure for this a few more times today in my manual and I'm still unclear on how to make the end float mesurment. Where do I measure? From what to what? and with what tool?

On the first page of this thread, I put a link to pictures that SHOW how to make the measurement; do I have to post every picture?

The dial indicator clamped to the tie-rod. There are several variations on how you can do this, but whatever gives a ridgid setup will do:

Zero the indicator:

Too much endfloat, so shim stack needs to be adjusted:

Re-zero indicator after removing (in my example) .005" shim:

Perfect:

 

[elrey]

That's the ticket, you are a god, Mr.Forbes! --elrey

 

[Keoke]

The manual for the 3000 seems to describe a
"very complex procedure" and I suppose I'd follow it.---

:Safest thing to do.----

...Wheel bearings can be finicky and wear premarturely if it's not set correctly.


There is one point in this discussion that needs to be clarified .

The Healey system seems "complicated" because the spacer has been designed and added to strengthen the Axel. The only way it can perform this function is to act as a column in compression while also properly preloading the bearings. --Fwiw--Keoke---


One other tip...Use a top notch grease...I have raced with Redline CV-2 grease in my wheel bearings and I can see a difference. My old grease would give me a season on a set of bearings...Going on 3 seasons with the same bearings using Redline grease... [/quote]

 

[Keoke]

As an aside, does anyone think the assemblers at the plant went 'by the book?

IF they did not learn during the day time they were sent to night apprentice school where they were conditioned,---Keoke-- :laugh: