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Front Hub Nut Torque Settings


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#1 Sleepy Stu

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Posted 10 March 2008 - 10:24 AM

Hi everyone

Was tighening up the front hub nuts yesterday as they seemed very lose and so i had a quick glance at ye olde Haynes.

All models except Cooper s and 1275GT 60 lbf/ft 83Nm

Cooper s and 1275GT 150lbf/ft 207Nm



Now i have a 1275GT but although this figure is probably right it seems ludicrously high to me. 207Nm :) my torque wrench doesnt even go that high? :)

Can anybody body shed some light on these figures for me please. Sorry but im one of those people who likes to know why something is as it is? ;)

Thx Stu

Edited by Stewart_GT, 10 March 2008 - 10:33 AM.


#2 Jammy

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Posted 10 March 2008 - 10:29 AM

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Just think about when your cornering hard, there is a whole load of force pushing against that nut!

Edited by Dan, 10 March 2008 - 01:17 PM.
Sorry Jammy, I had to remove that bit. It was wrong and dangerous.


#3 Dan

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Posted 10 March 2008 - 01:32 PM

The answer is....get a bigger torque wrench.

Drum braked (and Cooper 7" disc braked but we'll ignore them as they're rubbish) CV joints are set on plain ball bearings and have no pre-load. These are the type that only need torqueing to 60 lbft / 83 Nm.

All the disc braked Minis use taper roller bearing sets and need to be pre-loaded to the correct amount. So :

Where there are two split pin bores in the CV joint the hub nut must be torqued to 150 lbtft / 207 Nm, then tightened further to align the hole.
Where there is only one split pin bore the hub nut must be torqued to 193 lbft / 262 Nm, then tightened further to align the hole.

Both of these larger CV joints with taper roller bearings must be torqued and aligned twice, once using a large flat washer strong enough to take it and then WITHOUT DISTURBING THE JOINT remove the nut and flat washer and reassemble with the taper washer in place and re-torque, align and pin. The fan blade spacer is the right size to use as a washer, use two ideally for strength. Don't use the one you want to put back behind the fan as it will get damaged. Buy a new one to use as a special tool for this purpose. You must do this to ensure proper pre-load on the bearing. If you don't the taper washer will grab the CV before the bearing is seated and prevent the joint sliding through. The bearing will be slack and wear in no time.

If your bearings are loose, they are worn out. There is no adjustment in a taper roller bearing, it either is or isn't pre-loaded. They may be loose because someone fitted them without first seating them with a flat washer, because they weren't fully torqued or because they have become worn. In any event they are probably now damaged and you should replace them. If they haven't been driven in this loose condition and it is down to poor fitting they will still be OK but if any serious amount of miles has passed under the wheels since they became loose they need replacing. Check your CV joints for a ridge where the taper washer sits and if there is one linish it off as it will prevent the bearing seating properly.

Edited by Dan, 10 March 2008 - 01:34 PM.


#4 minivanman

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Posted 10 March 2008 - 06:41 PM

The fan blade spacer is the right size to use as a washer, use two ideally for strength.


DOH! I spent ages hunting round the garage the other day to try to find a washer the right size for this :thumbsup: Ta Dan!

#5 panelbeaterpeter

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Posted 10 March 2008 - 06:53 PM

I just use a breaker bar with an extension until the holes meets up! it always seems too tight, but I suppose it has to be.

#6 miniGTS

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Posted 22 March 2025 - 10:18 AM

What's the reason for the higher torque on the nut where the CV has 1 hole? Is it just so that the hole lines up for the split pin?

My torque wrench only goes to 225NM so wondering if it will be sufficient to torque to 225NM then just tightening further with a powerbar until the hole lines up for the pin?

#7 GraemeC

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Posted 22 March 2025 - 10:30 AM

In theory, CVs with one hole are made from a higher specification material and so need the higher torque to achieve the stretch and hence clamping force

#8 miniGTS

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Posted 22 March 2025 - 10:39 AM

I imagine the nut doesn't turn that much between 225 and 262NM which is why I wonder if it'll be close enough to 260ish if I align it with a powerbar after reaching 225NM. Would that be a fair assumption?

#9 mbolt998

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Posted 22 March 2025 - 04:38 PM

I was always told back in the day, "get the biggest wrench you can find and stand on it". Does anyone know what size those nuts actually are though? I'd quite like to treat myself to the proper wrench one day. I currently get them on and off with a fairly long adjustable spanner.



#10 Spider

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Posted 22 March 2025 - 04:55 PM

What's the reason for the higher torque on the nut where the CV has 1 hole? Is it just so that the hole lines up for the split pin?

My torque wrench only goes to 225NM so wondering if it will be sufficient to torque to 225NM then just tightening further with a powerbar until the hole lines up for the pin?

 

As Graham mentioned, a higher clamping force.

There's some more detailed info here;-

 

https://www.theminif...wheel-bearings/

 

You need to remember that the original hubs, CVs and other parts were originally designed for 10" wheels, with higher sidewall tyres that didn't grip as well as what was available in later years. They up-rated the Hubs, the CVs and increased the preloading on the bearings.

These up-rated CVs, when torqued up properly give superior wheel bearing life.

 



#11 Chris1275gt

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Posted 22 March 2025 - 04:57 PM

Front hub nut 1 5/16”

Edited by Chris1275gt, 22 March 2025 - 04:59 PM.


#12 miniGTS

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Posted 22 March 2025 - 05:33 PM

I'll torque up to 225NM and then some extra bit to align the hole with the castle nut. If it's aligned at 225NM then I'll tighten up to the next hole. Surely that would take it closer to 262NM.

The CVs I got from the local supplier have a 32mm nut which is annoying because I bought a 34mm for the nut that came off.

#13 GraemeC

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Posted 22 March 2025 - 05:40 PM

Front hub nut 1 5/16”


Or 34mm on some replacement CV joints.
(I have also come across cheap CVs with smaller AF nuts - they get binned immediately!)

#14 bikewiz

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Posted 22 March 2025 - 05:46 PM

These make it easier. Better quality and easier to line up the holes.

https://classicminis...lot-castle-nut/

 

 

 

 

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#15 Shooter63

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Posted 22 March 2025 - 05:54 PM

Minispares sell them now BTA249EVO

Shooter

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