Quick mid-brake-disc-change hub nut question (2010 110)

[Samblers]

Hi All,

A quickie...

Attempting my first brake disc change/ front hub assembly removal: 2010 Puma 110.

I've got the first (front) staked-type hub nut off, a struggle whereby the (admittedly cheap, in a blue packet) tube spanner was zero help and the cold chisel came out.

Any advice on tightening the new hub nut up when it all goes back together, given the noticeably high torque required (220Nm)? I wont be able to achieve that with the cheap tube spanner.

Tool shop time? Does it really need to be that tight?

Cheers in advance,

Sam

[p38arover]

Change to the old style hub nuts?

[Samblers]

Change to the old style hub nuts?

Hmm... seems on further reading that a few have done this, and is suggested in this thread here (https://www.defender2.net/forum/post158779.html)

Anyone got any thoughts on this? I like the idea of being able to disassemble/ inspect/ repair in the bush a little more easily.

[Samblers]

Just closing this out... I capitulated and bought a 52mm deep socket (and a torque wrench)

... it turns out that 210Nm, and the staked nut design, ain't so bad when you have decent tools. Lesson learned.

[roverrescue]

The draw back of the staked nut is in my opinion twofold

If you don’t remove the folded over tang adequately - the process of undoing said but Rogers the thread form

Secondly, although you may be able to re-use a stake nut - eventually you won’t be able to secure it in place once all nearby flange is folded and broken away from the machines locking groove.


Having said that - the spacer and high torque technique for a pair of tapered bearings gives a more consistent pre-load than other methods ....

For what it is worth I recently changed over my tdci to old style lock nuts

[POD]

I also changed to old-style paired nuts and lock tabs. There is another drawback to the single staked nut and spacer- the spacer is specific to those particular bearings in their brand new condition. It does not enable adjustment of preload when reassembling worn bearings nor when replacing bearings. I believe it is simply a manufacturing shortcut that removes the requirement for skill from the assembly process; just bang it all together and rattle it up with a big rattle gun set to hellish tight.

[towe0609]

I have the spacer, and paired nuts and tab. Best of both worlds?

Correct spacer as per shop procedure with proper gauge etc, and the inner nut done up to same torque as stake nut spec.

I'm no expert, but my logic (which I tested with Ian at MTE4x4 Morwell prior to closure) is this would allow me to re-use the nuts and spacer is just re-greasing existing bearings, but if an unplanned bearing change was required, to remove spacer (as I don't have a gauge) and return to the usual method of setting pre-load.

Be great to hear others thoughts on this approach.

[roverrescue]

It’s the same as gearbox rebuilds
Variable spacers are NOT in play for variance in bearing dimensions
They are used for variance In casting and machining variance

Same bearing number from three different manufactures including whoflungdunglast200km rubbish will be within microns

That UN-CNC machined stub axle you have will lie somewhere in the range of acceptable deemed by LR in 19dickety two which was +2metres - 0.765miles

Spacers take up variance in variable tolerance

For all intents and purposes bearings and Shells have zero tolerance


The only reason i wouldn’t use the spacer AND dual nuts is how do you work your “mojo” when you can just crank her home ???

[Samblers]

An interesting discussion, and, armed with a little more experience and knowledge than a couple of days ago, I decided to stick with the staked nut design...



If you don’t remove the folded over tang adequately - the process of undoing said but Rogers the thread form


A sharp chisel bent/cut the flange back out of harms way, its pretty thin/ soft.



Secondly, although you may be able to re-use a stake nut - eventually you won’t be able to secure it in place once all nearby flange is folded and broken away from the machines locking groove.


Other than in an emergency, re-using these (mangled) nuts is out of the question surely? They're very cheap.



Having said that - the spacer and high torque technique for a pair of tapered bearings gives a more consistent pre-load than other methods


Thats the thing... I see this is a significant advantage (to Land Rover, the average mechanic (me), and therefore to owners (also me), and worth putting up with the minor disadvantages - that the vehicle Engineer (and not the mechanic/ user etc) , via this arrangement, controls the bearing pre-loads.

Set and forget

[Samblers]

I believe it is simply a manufacturing shortcut that removes the requirement for skill from the assembly process; just bang it all together and rattle it up with a big rattle gun set to hellish tight.

This is a benefit to most, not a drawback.

I'm playing devils advocate here, for an alternate point of view, and in defence of the long-suffering Design Engineer.

Also worth considering are the risks (in terms of liability, and life, to LR, to everyone), of a poorly adjusted wheel bearing, poorly torqued nut, poorly staked washer, coming loose when a vehicle is at speed.

[POD]

It’s the same as gearbox rebuilds
Variable spacers are NOT in play for variance in bearing dimensions
They are used for variance In casting and machining variance

Same bearing number from three different manufactures including whoflungdunglast200km rubbish will be within microns



You make a very good point. Based on that, replacement OEM bearings in the same hub should be able to be used with confidence with the original spacer. Compensating for wear over the life of a bearing, not so much.

[Samblers]

You make a very good point. Based on that, replacement OEM bearings in the same hub should be able to be used with confidence with the original spacer. Compensating for wear over the life of a bearing, not so much.

Genuine question... what wear in the bearing needs to be compensated for? Are you suggesting that either the bearing race or rollers wear down, i.e. material is consumed, introducing additional end float (slack) within the overall assembly that has to be adjusted for?

[towe0609]

You make a very good point. Based on that, replacement OEM bearings in the same hub should be able to be used with confidence with the original spacer. Compensating for wear over the life of a bearing, not so much.

I only use Timkin bearings, and have spares of same on hand, so assume the only circumstance in which I'd need to change the spacer is if it became necessary to change the hub. It suits me to retain the spacers.

[roverrescue]

From what little I know and have read
Tapered roller bearing wear characteristics and life spans is up there in the Mechanical Engineers “We can debate this all night long” playbook!!

I think in this day and age of high tolerance / high strength alloys essentially a tapered bearing and race overall tolerances will remain on specification up to the point of failure.

I recall John from Western NSW saying he is still running well lubricated wheel bearings from 19dicketytwo with 917 thousand miles on them!

But seriously. Bearings die due to contamination or lack of lubrication. I would hazard a guess that if you measured the overall stack height of John’s well matured bearing and race against a brand new Timken there may indeed be some measureble variance

BUT I would also argue that the variance would be pretty insignificant !!!

Steve

[Tote]

Thanks for the info on this thread, I need to do the front brake pads and I've been trying to figure out the effort to regrease the bearings at the same time. From this all I need is a couple of new nuts, a big socket and a torque wrench. The explanation of how the spacer system works and the fact that you should be able to reuse the existing spacer with regreased or new bearings is a huge win.

Regards,
Tote

[Samblers]

Thanks for the info on this thread, I need to do the front brake pads and I've been trying to figure out the effort to regrease the bearings at the same time. From this all I need is a couple of new nuts, a big socket and a torque wrench. The explanation of how the spacer system works and the fact that you should be able to reuse the existing spacer with regreased or new bearings is a huge win.

Regards,
Tote

You might like to have a couple of bearing seals to hand as well - I replaced mine...

Good luck

[MLD]

Genuine question... what wear in the bearing needs to be compensated for? Are you suggesting that either the bearing race or rollers wear down, i.e. material is consumed, introducing additional end float (slack) within the overall assembly that has to be adjusted for?

the end float (fore and aft movement) that you refer to is taken up by pre-load and the stake nut. i think you meant to say the bearing is able to move laterally (or concentrically) on the bearing cup as the bearing material is eroded. To some extent this is also taken up by pre-load on the stake nut as you push the cone into the cup taking up the tolerance (until a point that the tolerance is too much). the spacer is against the bearing cup and doesn't affect pre-load of the stake nut save to say it offers a second point of contact to prevent the bearing cup moving out of its perfect vertical plane. as others have said, it was LR's way of making the process idiot proof (and i thank them for that for i am dangerous with a spanner and hammer). For what it is worth, on my 35 spline sals conversion the outer bearing ID is a bees **** smaller than the inner bearing, with a small shoulder against which the bearing cup rests for pre-load. Hard to see in the pic.
168761

[Samblers]

... the end float (fore and aft movement) that you refer to is taken up by pre-load and the stake nut. i think you meant to say the bearing is able to move laterally (or concentrically) on the bearing cup as the bearing material is eroded. To some extent this is also taken up by pre-load on the stake nut as you push the cone into the cup taking up the tolerance (until a point that the tolerance is too much). the spacer is against the bearing cup and doesn't affect pre-load of the stake nut...

Yep, just making the point that there is zero adjustment possible within the Puma assembly. The bearings are rigidly held in place between locknut, spacer (not shown, at pencil tip) and stub axle.

168762

[POD]

the end float (fore and aft movement) that you refer to is taken up by pre-load and the stake nut. i think you meant to say the bearing is able to move laterally (or concentrically) on the bearing cup as the bearing material is eroded. To some extent this is also taken up by pre-load on the stake nut as you push the cone into the cup taking up the tolerance (until a point that the tolerance is too much). the spacer is against the bearing cup and doesn't affect pre-load of the stake nut save to say it offers a second point of contact to prevent the bearing cup moving out of its perfect vertical plane. as others have said, it was LR's way of making the process idiot proof (and i thank them for that for i am dangerous with a spanner and hammer). For what it is worth, on my 35 spline sals conversion the outer bearing ID is a bees **** smaller than the inner bearing, with a small shoulder against which the bearing cup rests for pre-load. Hard to see in the pic.
168761

This is a bit difficult to follow but if I understand what you're saying, I'm sure it is incorrect. The spacer is between the two bearing cones, not the cups. The staked nut is tightened down on the cones but can only move them as far as the spacer allows- unlike the older style where the adjusting nut being tightened too much will result in excessive preload by moving the cups inward toward each other and deeper into the cups. With the spacer, the nut can be tightened as much as you like but the cones will not be preloaded more than the spacer will allow.

I know a bloke is not supposed to say this, but the information in this thread- particularly roverrescue's points- have prompted me to actually consider this and to change my mind about the spacer setup. When I think about it, it is of course correct that it is the hub casting and machining that will have variation from one to another, whereas the modern bearings will have effectively zero variation from one to the next and the wear will of course be as good as zero over the life of the bearing; so, unless one is replacing the hub- and assuming OEM bearings are used- the spacer will give the correct preload every time. This principle would apply to such things as diff pinion bearings and transfer case bearing spacers also. Way back when I was learning this stuff, they were not used so I have regarded them as a modern shortcut to be spurned.

[Samblers]

Totally agree with you POD.

Both setups can clearly work, but after thinking about the merits of both, it's clear why the switch to the locknut/spacer design was made, hence I chose to stick with it.

Quite enjoying the torque wrench too...

Sam