Dismantling BJ8 Front Hub From Caliper Disc

[pkmh]

Hello, my question for today is,

I want to remove, inspect and at the very least, repack all bearings to the front hub components.

I have already removed the front caliper from the brake disc and is now supported via use of a metal wire to prevent straining of my flexible brake hose.

The next step, it seems, is to first remove the split pin through the side opening on the hub [hole] in order to remove the axle nut inside the hub.

From here on, is there any thing else I should be aware of? Example, I may also want to remove the five securing nuts from the hub to the brake disc (do I have any other choice?). In so doing, will I be knocking out of balance (alignment) the hub to the brake disc?

Anybody else care to add advice as I proceed?

Thanks,

Paul

 

[BigGreen]

The Haynes manual page 182 /7;

"Should it be necessary to separate the disc from the hub, clamp the disc between soft faces in a vice and with a scriber or file mark the disc and hub so that the two parts may be refitted in their original positions ... "

Only necessary when the bearings come of with the hub, instead of staying on the stub axle.

<span style="font-weight: bold">Edit</span>; <span style="font-style: italic">see reaction by ed K.</span>

The discs / hubs of my Healey are of at the moment, bearings are in the hub.
I have not separated them yet. I am lucky to have someone do that for me ;-)

Hans

 

[Ed_K]

There is no need to remove the bolts holding the brake rotor to the hub unless you have it out of the car on your work bench and want to replace the rotors with new ones.
Remove the carter pin and remove the big nut.
Hold on to the front of hub and rock it left to right.
The front wheel bearing will pop loose and you can remove it.
Pull the hub with brake rotor attached straight out to avoid damaging the rear grease seal in case you are not going to replace it.
Pay attention to the order/positions of the little metal shims that should be next to the internal spacer.

If the hubs rotated freely before you began taking it apart, without any excessive end play or any wobble then the spacers can be placed back in the exact
positions they were in.
Read the shop manual about how to properly retorque the wheel bearing nut when you are done cleaning, inspecting and regreasing everything.

Hope you have plenty of shop rags !

:hammer:
Ed

 

[Brinkerhoff]

You would only separate the disc from the hub if the disc were to be replaced. I use an air impact gun for the bolts & nuts. Just make sure the faces where they mate are clean. Remove the stub nut and the whole assy. slides off. If the inner brg. remains on the stub axle come behind it with two large flat bladed screwdrivers to pry it off. Its not pressed on so will slide off easily. Of course you need to carefully save the shims that are inside of the outer bearing as they set up the proper distance between the two bearings. Kevin

 

[pkmh]

Thank you for the great advice so far.

The only thing that caught me off guard somewhat is these shims mentioned above.

I do have all shims accounted for or found within the hub assembly on the passenger side. 4 in total to be exact.

The part that has me off guard for the moment is, I believe all these shims should be placed between the "Distance Piece" and the "Outer Bearing."

As I took everything out, I somehow felt one of these shims was placed between the exterior side of the outer bearing and the outer washer. But that part is sketchy now and it just doesn't seem to make sense to do that, anyway.

Correct me if I'm wrong, but these shims are placed to make up the slack between the inner and outer bearing, after the distance piece is set. Am I correct??

I usually make sketches as I go but again, this bit caught me off guard.

On another note, I am pleased I did not need to remove the nuts from the hub to the brake disc or so far, I didn't not bother. Overall, evrything seems to be wearing evenly and with little if any corrosion, as the good book says.

Paul

 

[Brinkerhoff]

When correctly adjusted ( via shims) and the large stub nut tightened the hub should still spin freely but have no end float. Clean the bearings, lightly oil them and reassemble to check. When you are confident they are shimmed correctly , then you can pack them with grease and re assemble. Kevin

 

[57_BN4]

Sounds like the last guy to tighten up the wheel bearing clearance was trying to be helpful by putting the shim he took out under the washer for safe keeping.

I reckon you'll have just the right number of shims to get one side perfect and the other side either way too loose or too tight. Life is never that easy.

New shims available from the usual suspects.

Andy.

 

[Bob_Spidell]

...
Correct me if I'm wrong, but these shims are placed to make up the slack between the inner and outer bearing, after the distance piece is set. Am I correct??

Paul

Not quite. The distance piece and shims are used to set the distance between the inner and outer bearings to correctly pre-load the bearings in their respective races. Not enough shim thickness and the preload will be too great (and could lock up the hub), too much shim thickness and you'll have too much end float.

Like someone mentioned, you start with too much shim then remove shims until the end float is all but gone. Usually, you need about 0.030" of shims, give or take.

 

[Randy Forbes]

...
Correct me if I'm wrong, but these shims are placed to make up the slack between the inner and outer bearing, after the distance piece is set. Am I correct??

Paul

Not quite. The distance piece and shims are used to set the distance between the inner and outer bearings to correctly pre-load the bearings in their respective races. Not enough shim thickness and the preload will be too great (and could lock up the hub), too much shim thickness and you'll have too much end float.

Like someone mentioned, you start with too much shim then remove shims until the end float is all but gone. Usually, you need about <span style="font-weight: bold">0.030"</span> of shims, give or take.

I believe that to be a TYPO; should be .001 - <span style="font-weight: bold"> <span style="text-decoration: underline">.003"</span> </span> :wink:

I strive for "0.000" but that can be tricky to measure, so if you're reading .001 - .003", you're in good shape.

If you go from "this link" forward and back a few pictures, you should get a (visual) idea of the process: https://www.spcarsplus.com/gallery3/index.php/reMKIII/IMG_2618

 

[Bob_Spidell]

Not quite. The distance piece and shims are used to set the distance between the inner and outer bearings to correctly pre-load the bearings in their respective races. Not enough shim thickness and the preload will be too great (and could lock up the hub), too much shim thickness and you'll have too much end float.

Like someone mentioned, you start with too much shim then remove shims until the end float is all but gone. Usually, you need about <span style="font-weight: bold">0.030"</span> of shims, give or take.

I believe that to be a TYPO; should be .001 - <span style="font-weight: bold"> <span style="text-decoration: underline">.003"</span> </span> :wink:

Nope. Please re-read my post ... I said 'shims,' not 'end float.'

 

[Randy Forbes]

Not quite. The distance piece and shims are used to set the distance between the inner and outer bearings to correctly pre-load the bearings in their respective races. Not enough shim thickness and the preload will be too great (and could lock up the hub), too much shim thickness and you'll have too much end float.

Like someone mentioned, you start with too much shim then remove shims until the end float is all but gone. Usually, you need about <span style="font-weight: bold">0.030"</span> of shims, give or take.

I believe that to be a TYPO; should be .001 - <span style="font-weight: bold"> <span style="text-decoration: underline">.003"</span> </span> :wink:

Nope. Please re-read my post ... I said 'shims,' not 'end float.'

Granted, but still mis-leading.

 

[pkmh]

Still not quite ready to attempt to reinstall my bearings, etc., to the hub. All of my existing bearings, shims, spacer and all related parts have been cleaned of the old grease. The condition of the old grease appeared to be fine, or no hardening or discoloration (anything else I should be looking for when observing old grease?). The bearings and racers all appear good, no scoring, corrosion, uneven wear, etc., or that I can tell by visual observation.

But I had to do a little research on even simple terms like "end float" and what to look for when I start putting it all back together.

And if I am reading the one part correctly, they say to test for end float by "grasping the hub with one hand and with the other hand hold the base of the lower king pin collar part of the stub axle assembly just above the fulcrum pin, behind the backing plate. Try to move the hub in and out parallel to the stub axle. Grabbing the lower king pin collar will enable you to differentiate between flop from king pin wear and hub movement."

I assume another word for the lower king pin collar part is the swivel axle (or what I will call the spindle?).

I also found out the advice offered above regarding lightly lubricating the bearings and shims is appropriate in order to attempt to achieve zero end float and zero drag (or as much as possible, as indicated in the above posts).
Otherwise, I might be creating false results due to over greasing (excessive oozing).

My major concern is the trial and error process of determining how many shims will be needed to satisfy zero end float (or as much as possible). I do not have micrometers or other instruments for measuring shim thicknesses, other than saying that all the four shims I removed measure a total of about 1/32" thick, combined (Three of the shims are equal in thickness and almost paper thin and the fourth is slightly thicker). I understand I am suppose to tighten the axle nut and then back off a notch, then do a free spin of the hub to test for grinding, locking up, etc. This is also done before greasing everything up.

I will have to proceed using feel more than anything else. Therefore, is the above approach adaquate enough to proceed?

Paul

 

[Brinkerhoff]

Paul , its tricky to fit the shims over the stub threads and up next to the distance piece. Use a little grease (and a lot of patience !) on them so they stick together and a small flatbladed screwdriver to ensure that you've pushed them past the threads or you'll ruin them when you slide the outer bearing on. Leave one of the thinner shims off and assemble. As you tighten the nut spin the hub. Notice when the hub stops spinning freely and starts to drag. The shop manual has the spec for torque on the stub nut. ( on a boat trailer you would tighten up until it drags then back off a notch , not on a Healey). Since you don't have a dial guage to measure end float you'll have to have a feel for it. Its pretty simple , add a shim until the hub just spins freely when the nut is tightened to spec. Like Randy said exact zero end float is hard to get to but err on the positive side of it spinning freely NOT on the side of slightly dragging. Packed bearings make it very hard if not impossible to get it right. For the design to have the strength it was intended for its important to tighten the nut to spec. and still have the hub spin freely. If you have a negative end float you have a "pre load" condition on the bearing and you risk overheating the bearings. If the large nut does not line up with the cotter pin hole when tightened , remove it and take a large flat file to the face of it until it does. Hope this helps. Kevin

 

[BigGreen]

All the information above made me confident enough to try myself.
Took the bearings out and cleaned them up. They look fine
Exept for the half shim I found in the grease
Must have been someone who needs all this information also

Thanks to everyone, I like this forum !!

Hans

 

[pkmh]

This afternoon, I completed the task of testing for end float and drag by installing one shim at a time on the passenger side hub.

Again, All four shims I had on the passenger side equaled a total thickness of about 1/32". Three are 'paper thin' or flimsy in nature and the fourth thicker and more rigid by comparison. That's the best I can describe without the use of a micrometer.

As a test, I started with no shims with cleaned, unpacked bearings and spacer in place as well as the washer and axle nut. I noticed some end float evident along with a slight grinding sound as I spun the rotor. Then using only one shim became less noticable and less so with two shims. I went back and forth between using two and three shims and decided to go with the third shim in place.

With each shim in place, I would also spin the rotor after installing and lightly tightened on axle nut. If I tightened the axle nut hard, then spinning became greatly reduced. This was true with one, two or three shims in place. I did not tighten the heck out of nut but left it taut, therefore. Or, if I went to the next notch on the nut, then the wheel would hardly spin. I recall one's post above where he mentions I should use a flat file on the back side of the nut. But I did not feel that was necessary for the nut became taut enough to insert the pin with no drag and no end float present.

After packing the bearings and putting the tire back on, it spun slightly better than before and in fact, about double the ease than the driver side as present.

I am spelling out the above for I believe I got the knack but not quite totally confident I did it perfect.

As another test, could I drive it around a bit and then jack it up and test for float and drag again?

 

[big6]

“With each shim in place, I would also spin the rotor after installing and lightly tightened on axle nut. If I tightened the axle nut hard, then spinning became greatly reduced. This was true with one, two or three shims in place. I did not tighten the heck out of nut but left it taut, therefore. Or, if I went to the next notch on the nut, then the wheel would hardly spin.”

The sub-axle castle nut must be torqued to 40 to 70 lb/ft. (The difference in torque is for aligning the split pin but the minimum torque on the axle castle nut is 40 lb/ft.) The bearings, spacer, and shims when installed and torqued properly strengthens the sub-axle. By not installing the component parts correctly can result in a broken sub-axle or seized wheel bearings. Be advised to over shim and torque the axle nut and use a dial test indicator to check the end-float. You can purchase a dial test indicator and mount from HF for ~$20- $25 that is adequate to setup the front hubs. Again if you cannot torque the axle nut to at least 40 lb/ft without losing free movement the shim setup is not correct.

 

[Brinkerhoff]

Paul , it sounds like you need more shims in addition to the ones you have. Like big 6 says , if you have too many shims in place the castle nut will be tightened to spec and you will be able to feel the hubs end float by grasping it firmly and pulling/ pushing it. Reduce shims to the proper point. Kevin

 

[pkmh]

Thanks folks for the feedback. I have learned a lot from this.

Maybe the job done prior to my looking at this was not done entirely correct. That is to say, definitely three shims were used (if not four) and after tightening on the axle nut I still have a lot of drag (but so far, no end float problems that I can detect).

To further summarize, assuming all bearings and axle have no defects, then it is my understanding that by placing proper "X" number of shims between the spacer and outer bearing, I should be able to eliminate both end float (to near zero as possible) and have minimal drag and be able to tighten the axle nut between 40 - 70 lb/ft, after all is said and done.

And I would be slightly better off adding more of shims than less to prevent pre-loading the bearings or producing overheating or seizing up.

I will need to go back and try installing that fourth shim and test the results of end float, drag, etc.

As a matter of principle, a sign of normal bearing wear (and/or axle wear for that matter) would mean the requirement of more shims to compensate or make up end float, correct? Also, are there specifics or guidelines on minimum required bearing thickness or when bearings (or axle) should be replaced?

Also, considering the way everything is presently assembled, what would be the problem, if any, with the idea of driving the car around for a little bit and then retest end float, drag and tightening up on the axle nut? I had someone's opinion saying that was okay but curious to hear more on the subject.

Thanks,

Paul

 

[Bob_Spidell]

re: Maybe the job done prior to my looking at this was not done entirely correct. That is to say, definitely three shims were used (if not four) and after tightening on the axle nut I still have a lot of drag (but so far, no end float problems that I can detect).

>>> Not good. The number of shims required is irrelevant, the hub should turn freely with very little effort, with little or no end float. The book procedure is to use more shims than necessary, measure end float then remove shims to (nearly) zero the end float. For example, if you add 0.040" shims and have 0.010" of end float, you need approximately 0.030" of shims. You need to fully torque the nut to gauge end float; best to torque say, halfway, to seat the bearings then back off and torque fully. As someone else mentioned, it doesn't hurt to oil the bearings lightly to prevent damage (but I'd clean them well before grease-packing).


re: To further summarize, assuming all bearings and axle have no defects, then it is my understanding that by placing proper "X" number of shims between the spacer and outer bearing, I should be able to eliminate both end float (to near zero as possible) and have minimal drag and be able to tighten the axle nut between 40 - 70 lb/ft, after all is said and done.

>>> Again, the number of shims is irrelevant. It's the total thickness that counts. Randy's snide comments notwithstanding, you'll likely need 0.030" of shims, give or take (1/32" is 0.03125"). You can do this with a 0.020" shim and a 0.010" shim, or 6-0.005" shims or 3-0.010" shims, etc.

Don't sweat the torque numbers; torque as tight as you can and still line up a slot on the castellated nut with the hole in the hub for the cotter. I undertorqued one time and spun the keyed flatwasher on the hub threads. Sounded just like a blown bearing, but the noise went away after the washer had traveled as far as it could.


re: And I would be slightly better off adding more of shims than less to prevent pre-loading the bearings or producing overheating or seizing up.

>>> I don't have the manual handy, but IIRC the procedure is called 'properly pre-loading the bearings.' Pre-loading isn't a bad thing, your pinion bearings require enough so that the pinion 'snaps back' when rotated. You want the bearings to seat properly in their races; allowing 0.001-0.003" of end float assures the bearings won't be too pre-loaded. I've done it 'by the book,' but have found if you add shims till you can feel just the slightest movement when pushing/pulling the hub in and out you'll be fine.


re: I will need to go back and try installing that fourth shim and test the results of end float, drag, etc.

As a matter of principle, a sign of normal bearing wear (and/or axle wear for that matter) would mean the requirement of more shims to compensate or make up end float, correct? Also, are there specifics or guidelines on minimum required bearing thickness or when bearings (or axle) should be replaced?

>>> Any sign of bearing wear means get new bearings and, preferably, new races as well. Bearings will 'wear in' to their races a little over time, which will increase the end float. Hence a slight pre-load is desirable.



re: Also, considering the way everything is presently assembled, what would be the problem, if any, with the idea of driving the car around for a little bit and then retest end float, drag and tightening up on the axle nut? I had someone's opinion saying that was okay but curious to hear more on the subject.

>>> The consequence is possibly damaged bearings and races at the least, and maybe worse (you're also making unnecessary work for yourself). There is a correct and effective method for performing this task; follow the procedures and life will be good. I believe my BJ8 has its original bearings and races and it has 170K miles.

Also, replace the seal while you're at it. There is a spacer on the inside of the stub axle upon which the seal rides; make sure it is clean. If it's only got some light scratches clean it up with emory cloth, if it has deep scoring replace it. Be sure to lightly grease the inner lip of the seal before installing, and don't overpack grease in the hub (just pack the bearings thoroughly; don't add 'extra just in case').

 

[pkmh]

Thank you Bob,

As I ask and sometime reiterate, it helps me to understand and ask more specifics. I never knew how involved all this could be, thinking it was like taking sealed bearings, tightening all the way and then back off a notch. Obviously, From all the above, this is not the case.

I appreciate the time you and others take in responding.

Much appreciated.

Paul