Hi All. Am I correct in assuming that if the wheel bearing nut on my Al-ko chassis is not castelated and is a large nut with no splitpin, then it has sealed bearings and requires a dealer to carry out even the simplest of tasks such as cleaning the dust out or replacing the shoes. If this is so, why have alko not designed the drum and hub to seperate like car manufacturers, and how much would I expect to pay at a dealer to get the job done. thanks for any help, Cheers .
Al-ko Hub Nuts
- Thread starter Barkas
- Start date
These nuts are known as "one shot" nuts and may be taken off to do maintenance but must be replaced by new ones each time.
There are 2 different sizes and they require a heavier duty torque wrench
http://www.banburytrailers.co.uk/index.php?manufacturers_id=29=AL-KO alko
http://www.banburytrailers.co.uk/index.php?manufacturers_id=29=AL-KO alko
That explains why after each service, there is a bag of 4 used nuts left in my TA van.
I'd often wondered why they left them in - cheers !
How important is it to remove the nut?
I pose the question in that there is nothing in the drum that requires regular maintenance.
Also its not a stated Al-Ko maintenance requirement.
The bearing is sealed for life,
Al-Ko state wear on the shoe is at its greatest by the provided inspection hole.
Arguably you should molybdenum grease up the metal to metal contacting points.
There might be a point in removing the dust.
However over years of annually removing the drums from my earlier vans I never found dust built up where it could cause problems and with 35,000 miles on that van I never had much shoe wear certainly never to need a change.
I posed this question to the fitter doing the warranty service on my new van; he concurred there was no need. It however makes it easier to inspect the shoes, it was the dealers policy and clients want to be given two used nuts. He said they rarely find any problems unless the linkage was incorrectly adjusted. The biggest incident of failure he said was wheel bearing roughness/play/breakup which was detectable without removing the nuts.
Just a thought.
See:
http://www.al-ko.co.uk/edit/files/support/BrakingOperation.pdf
I pose the question in that there is nothing in the drum that requires regular maintenance.
Also its not a stated Al-Ko maintenance requirement.
The bearing is sealed for life,
Al-Ko state wear on the shoe is at its greatest by the provided inspection hole.
Arguably you should molybdenum grease up the metal to metal contacting points.
There might be a point in removing the dust.
However over years of annually removing the drums from my earlier vans I never found dust built up where it could cause problems and with 35,000 miles on that van I never had much shoe wear certainly never to need a change.
I posed this question to the fitter doing the warranty service on my new van; he concurred there was no need. It however makes it easier to inspect the shoes, it was the dealers policy and clients want to be given two used nuts. He said they rarely find any problems unless the linkage was incorrectly adjusted. The biggest incident of failure he said was wheel bearing roughness/play/breakup which was detectable without removing the nuts.
Just a thought.
See:
http://www.al-ko.co.uk/edit/files/support/BrakingOperation.pdf
I understood from the back of my mind that Alko requirement was to remove the hubs at the second annual service onwards
I have always found dust build up in my hubs when checking and a visual inspection does no harm
Must be the way I drive
That's a great link with excellent clear diagrams
I have always found dust build up in my hubs when checking and a visual inspection does no harm
Must be the way I drive
That's a great link with excellent clear diagrams
I have also read in the haynes caravan manual that if you have any problems at all with the wheel bearings, the drums have to be removed, packed up in a box, and sent of to Al-ko to have new bearings inserted as its a specialised job, and when they return you need a huge torque wrench to achieve a pull down of 250NM. All this tells me that if a wheel bearing goes while your on holiday, thats your trip over. Cant believe Al-ko have gone in this direction with these axles,and it appears that all vans are now fitted with this type of bearing.
Damian
Moderator
- Mar 14, 2005
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The torque for the Al-Ko hub nut is 290NM, for the BPW hub nut it is 280NM, both figures + or - 10%
Whilst it is true that a general guide to shoe state can be seen through the inspection hole, if you are slim enough to bend yourself around the axle to actually see into it, you cannot see if the rest of the pad material is in good condition, as a fair few have suffered the material crazing and falling off, or the whole pad becoming detached from the shoe.
It is also not possible to clean and lubricate the adjuster and piston and the reverse sliding mechanism with the hub in place, so it has to come off, also to inspect the inner bearing to make sure it is not leaking, which has happened, and will happen again.
Whilst it is true that a general guide to shoe state can be seen through the inspection hole, if you are slim enough to bend yourself around the axle to actually see into it, you cannot see if the rest of the pad material is in good condition, as a fair few have suffered the material crazing and falling off, or the whole pad becoming detached from the shoe.
It is also not possible to clean and lubricate the adjuster and piston and the reverse sliding mechanism with the hub in place, so it has to come off, also to inspect the inner bearing to make sure it is not leaking, which has happened, and will happen again.
IT seems strange that the Alko website gives the same torque setting for the 2 different size nuts,see below
AN 7001 AL-KO Axle Nut
AL-KO one shot axle nut, suits 1637 and 2051 hub drums, 32 mm across flats. These nuts MUST NOT be reused, always fit new nuts, and torque to 290 Nm.
AN 7001 AL-KO Axle Nut
AL-KO one shot axle nut, suits 1637 and 2051 hub drums, 32 mm across flats. These nuts MUST NOT be reused, always fit new nuts, and torque to 290 Nm.
Damian
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- Mar 14, 2005
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There is nothing strange at all with the torque figures for Al-KO being the same.
The difference is in the drum size (and the brake size) but the stub axle is the same cross section.
BPW on the other hand have adopted a lower setting to suit their stub axle size and brake size.
The difference is in the drum size (and the brake size) but the stub axle is the same cross section.
BPW on the other hand have adopted a lower setting to suit their stub axle size and brake size.
Hi Damian
One stub axle is a bigger thread than the other hence 2 different size nuts
I would have expected a higher torque for the bigger nut
One stub axle is a bigger thread than the other hence 2 different size nuts
I would have expected a higher torque for the bigger nut
Hi again Damian
I am basing my comments on what I found when my caravan wheel came off
The grease cap was knocked off and the thread on the end of the axle was slightly damaged
I cleaned up the threads but the one shot hub nuts I carry would not go on to start the thread as the axle on the heavy duty brakes seemed thicker
Subsequently Alko refurbished the axle
I am basing my comments on what I found when my caravan wheel came off
The grease cap was knocked off and the thread on the end of the axle was slightly damaged
I cleaned up the threads but the one shot hub nuts I carry would not go on to start the thread as the axle on the heavy duty brakes seemed thicker
Subsequently Alko refurbished the axle
It would be the surface area of the flange of the nut and the friction it creates, that determines any different torque requirement. Perhaps then, given the 20% tolerance, the difference in the two flange sizes is not enough to worry about?
Hi gary
If the leverage is being applied to a bigger nut would this result in a higher torque at the thread anyway??
If the leverage is being applied to a bigger nut would this result in a higher torque at the thread anyway??
Hi John,
No - that's the reason for using a torque wrench - it sets the "tightness" at the join of the nut and hub surface.
Robert
No - that's the reason for using a torque wrench - it sets the "tightness" at the join of the nut and hub surface.
Robert
Thanks Rob
That's what I understood but it just crossed my mind that if there was a greater distance from the flats to the centre then maybe more leverage would be applied etc
That's what I understood but it just crossed my mind that if there was a greater distance from the flats to the centre then maybe more leverage would be applied etc
This is one of those times I wish PC would have an 'edit' button?!
What I was getting at is as Rob says the torque applied gives a clamping pressure, to achieve this, you need to overcome any friction on the way.
So it's not just the flange surface area but also as you say John, being at a bigger radius. Also though, given the same thread pitch at a bigger diameter, this would reduce the torque required for a given pressure to be applied, or for the same torque, increase the applied pressure.
What I was getting at is as Rob says the torque applied gives a clamping pressure, to achieve this, you need to overcome any friction on the way.
So it's not just the flange surface area but also as you say John, being at a bigger radius. Also though, given the same thread pitch at a bigger diameter, this would reduce the torque required for a given pressure to be applied, or for the same torque, increase the applied pressure.
- Jul 15, 2008
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This discussion, highlights for me, how foolish it is to rely on this design to hold a wheel on an axle of a road going vehicle.
Far better to have a mechanical locking device such as a split pin, a system still employed on millions of vehicles.
A system that also lends itself to easier maintenance and repair without specialist tools in non specialist workshops.
Barkas is right to point out that the brake drum can also be easily removed seperately for maintenance and inspection.
Far better to have a mechanical locking device such as a split pin, a system still employed on millions of vehicles.
A system that also lends itself to easier maintenance and repair without specialist tools in non specialist workshops.
Barkas is right to point out that the brake drum can also be easily removed seperately for maintenance and inspection.
without swaying to one security method or the other,whilst a split pin is sound,the hole weakens the shaft.the casette or unitised bearing setup basically takes out human error,for people who cant set up taper rollers.supposedly sealed for life.
All come with a distance spacer built in eliminating the need for split pins as there is something to tighten up to.the nut is still a lock nut.probably as a back up.we use them on 100mm shafts,and torque to 1200lbs ft.
All come with a distance spacer built in eliminating the need for split pins as there is something to tighten up to.the nut is still a lock nut.probably as a back up.we use them on 100mm shafts,and torque to 1200lbs ft.
- Jul 15, 2008
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Most people would agree that F1 is at the pinnacle of automotive engineering.
They tried using the just one nut torque system.
After several costly wheel losses they have reverted to a mechanical locking device in the form of a clip.
Remember that actual wheel nuts use the torque system, but there are usually four or five that have to undo at the same time for a wheel to come off.
Yet wheels still do come off!
They tried using the just one nut torque system.
After several costly wheel losses they have reverted to a mechanical locking device in the form of a clip.
Remember that actual wheel nuts use the torque system, but there are usually four or five that have to undo at the same time for a wheel to come off.
Yet wheels still do come off!
this set up been fitted to cars for many years no prob might check if bearing has part no on it they must be car derived and bet S K F are main suppliers to chassis makers easy to press in and out see local garage might do it you say sealed for life but very little grease inside
I am very interested to hear from anyone who can help me with a situation I find myself in.
I had a wheel come off last week on our first outing of the year. It has done some damage to the bodywork but more importantly has damaged the stub axle and the engineer has advised me that it will have to go back to Alko to be refurbished.
Can anyone tell me how long Alko will take to carry out this work as we are supposed to be going on a long holiday abroad with the van shortly.
Thanks
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