# HUB Separating from Axle



## aussietrail (Sep 24, 2004)

Hi Guys,

This could be related to the older model xtrails, as such you guys in Canada may not have experienced this phenomena but the guys in UK and other parts of the world where the exy was sold since 2001-2002 may have heard about it.

I have a new forum member here in Australia post this problem which sounded a bit strange and this is the first time I come across it.

Basically this is what he had to say:



> In August last year I started hearing a strange rubbing noise from front left wheel. I couldn't find any evidence that the tyre was rubbing anywhere and took it to the local (highly-reputable) Nissan dealer - FTG Nissan who could not identify any problem and suggested that it was probably brake pads rubbing which they had indicated needed replacing. I was unconvinced and after a few more weeks and the noise getting worse, I took it to a local mechanic. He found that the Hub had completely separated from the axle and the splines that hold the hub in place had ground away. $600 later, the hub and stub axle were replaced and everything was normal again. I had the car back at FTG Nissan 3 weeks ago for its 110,000 service which picked up nothing unusual (apart from fact that I still needed brake pads).
> Today, I had the car in at the local brake specialist who replaced my pads and brought to my attention the fact that the front LH hub had AGAIN separated itself from the axle. They asked me to very carefully drive the vehicle home as they considered it dangerous. These guys had no knowledge of the previous fault. I am worried that I have a lemon as I cant find any other instance of this fault in this forum. Car has 115,000 kms on it and basically is just a local runabout. It has done no 4WD'ing. I bought it in 2005 with 85,000 kms on the clock.


Now, this problem not only sounds serious but it is a life threatening fault which could cause a disaster if the hub and consequently the wheel got separated from the axle while in motion.

Any feedback would be greatly appreciated, as I couldn't find anything similar from the search I have conducted on the net.


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## Sulphur man (Sep 6, 2005)

Thanks J, good to be aware of a potential failure!


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## aussietrail (Sep 24, 2004)

Hi Guys,

Our member with this problem has finally got to the bottom of this issue and you will be surprised to hear it!

Rather than have a tessalated spacer washer then a split-pin to secure, apparently Nissan just put the split-pin in place and loctite the nut. The Nissan dealer to confirmed that this was normal. Apparently it is. 

Therefore if any impact (even a minor kerb bump) were to cause the loctite seal to break, the nut that secures the hub can fairly easily back itself off several turns and allow the hub & wheel bearing to be completely mashed (over time obviously). 

This dodgy way of securing the hub in place has DIRECT impact on all the premature bearing wear issues we have been hearing about and which a couple of members from this forum already experienced.


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## stuMcstu (Jun 23, 2007)

aussietrail said:


> Hi Guys,
> 
> This could be related to the older model xtrails, as such you guys in Canada may not have experienced this phenomena but the guys in UK and other parts of the world where the exy was sold since 2001-2002 may have heard about it.
> 
> ...


Just replying to your message I bought my x-trail 12mths ago now with only 22,000 miles on the clock it was taken in for M2 service at 27,00 miles everything ok but my main dealer said he had adjusted my off side front wheel bearing for some reason- about 1,000 miles later I heard a grinding noise and found the hub nut had completely backed off the only thing holding the assembly together was the split pin. hub etc and various other items needed replacing £860 later everything seemed ok. at this years service they said they have adjusted the nearside wheel bearing, which made me nervous again. I have now purchased 4 new hub nuts and after machining them down will use them as lock nuts.


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## aussietrail (Sep 24, 2004)

Thanks for sharing this information with us. I will be doing exactly the same and fitting locking nuts to the hubs to be on the safe side. I can't afford this type of service bill now that I am out of warranty! I can't believe Nissan would do something stupid like that to save a couple of cents!!


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## LEONGSTER (Apr 9, 2006)

Does anyone know the sort of bearings used in the XTY - Are they tapered or cylindrical?


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## aussietrail (Sep 24, 2004)

Ed, I believe they're cylindrical. This what the mechanic told me yesterday when we were talking about ways to solve this error. He gave me some excellent ideas which I'll be doing to rectify this design fault and I'll make sure I'll share them with you when done and post pics.


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## Revhead Kev (Apr 1, 2007)

Both here and ours ofcourse Jalal


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## aussietrail (Sep 24, 2004)

Revhead Kev said:


> Both here and ours ofcourse Jalal


You don't even have to mention it mate LOL


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## LEONGSTER (Apr 9, 2006)

aussietrail said:


> Ed, I believe they're cylindrical. This what the mechanic told me yesterday when we were talking about ways to solve this error. He gave me some excellent ideas which I'll be doing to rectify this design fault and I'll make sure I'll share them with you when done and post pics.


Thanks, Jalal. That's what I thought too. I've serviced my own wheel bearings several times in the past (tapered and cylinderical type) and from what I've seen split-pin nuts are used only with taper bearings.

Where cylinderical bearings are used, these normally require a special hub nut which has something called a "friction controlled" surface treatment which deforms under torque. These types of hub nuts can only be used once and must be replaced each time the nut is taken off.

It's of paramount importance to use the correct hub nut and to have the threads perfectly clean upon installation. 

I suspect that in some of the cases of the hub coming off, either there was tampering involved, or the nut was not replaced with a fresh, correct one, or the mechanic may have unknowingly used Coppaslip on the threads.

Hope this is useful.


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## LEONGSTER (Apr 9, 2006)

LEONGSTER said:


> Thanks, Jalal. That's what I thought too. I've serviced my own wheel bearings several times in the past (tapered and cylinderical type) and from what I've seen split-pin nuts are used only with taper bearings.
> 
> Where cylinderical bearings are used, these normally require a special hub nut which has something called a "friction controlled" surface treatment which deforms under torque. These types of hub nuts can only be used once and must be replaced each time the nut is taken off.
> 
> ...




Well, I just got ahold of a front wheel bearing set with installation instructions I had lying around - and there's something I posted previously that needs correcting:

1. Wheel bearings, although they may appear cylindrical on the outside, are actually tapered bearings (to cope with vertical as well as lateral load forces). The set I had came with a replacement hub nut (none-split pin type) which must be replaced each time it's removed, and some loctite.

Sorry for the error chaps.


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## aussietrail (Sep 24, 2004)

Hi Ed, I guess my mechanic gussed wrong, sorry about that, because he didn't actually remove the wheel to have a look and just based his assumption on another nissan model.

The locking pin doesn't sit on the hub nut, it actually sit right in front it on the shaft (see this diagram)



The problem we're facing is that theere are 2-3 treads between the edge of the nut and the locking pin and this how the nut sometimes gets loose until it reaches the pin and stops.


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## LEONGSTER (Apr 9, 2006)

aussietrail said:


> Hi Ed, I guess my mechanic gussed wrong, sorry about that, because he didn't actually remove the wheel to have a look and just based his assumption on another nissan model.


J, the both of you were not wrong to think so as the roller bearing - to all appearances - does appear cylindrical. It's internals are only distinguishable upon disassembly, at least to the layperson like me.

As for the hub problems we've been hearing of here, I wonder how much of it is attributable to poor design, or corrosion of the bearings or axle splines - perhaps due to immersion in (salt) water from off-roading?


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## aussietrail (Sep 24, 2004)

Ed, I don't think it has anything to do with off-roading. The problem happened to members and xtrailers who have never taken their exy off-road. I can only presume that it is a design fault as that hub nut needed to have a locking crown sitting on it and the locking pin needs to go through that crown to stop any movement.


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## Revhead Kev (Apr 1, 2007)

Does anyone know of something like a "slip-on crown" which we might be able to retrofit with new pins ?
If there is a few threads space between the locking nut and the pin, maybe this was designed for but not implimented in final assembly.


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## aussietrail (Sep 24, 2004)

Kev, this is what I mentioned in my previous reply  a locking crown


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## Revhead Kev (Apr 1, 2007)

Haven't found any.
Do you think the space would be enough for where the top ring of a nyloc nut might fit ?
Or maybe we could just use a spring washer as a spacer under the nut ?


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## aussietrail (Sep 24, 2004)

I don't know that yet Kev, but I have the locking crown sitting on my desk as a sample. The mechanic and I were going to see if we can fit another nut in front of the one that is already there to fill the gap between the hub nut and the locking pin and then put the locking crown on the second nut so the locking pin can go through it (the crown that is).


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## LEONGSTER (Apr 9, 2006)

aussietrail said:


> Ed, I don't think it has anything to do with off-roading. The problem happened to members and xtrailers who have never taken their exy off-road. I can only presume that it is a design fault as that hub nut needed to have a locking crown sitting on it and the locking pin needs to go through that crown to stop any movement.


Jalal, do send me a pic of the axle stub and hub nut when you have this. I'll seek the opinion of an automotive engineer I may know of ; -) 

Thanks.

Eddie


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## The Mad Hat Man (Oct 3, 2006)

yuz please - piccies please


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## stuMcstu (Jun 23, 2007)

I have photo's of the hub nuts that I have just had modified for my x-trail after the offside hub nut came loose [same as reported above being a newbie I have not yet worked out how to insert my images, i took them with my digital camera can anyone help


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## ValBoo (May 19, 2003)

stuMcstu said:


> I have photo's ................I have not yet worked out how to insert my images,................. can anyone help



see below link for "How To" on picture posting 
http://www.nissanforums.com/x-trail/103294-picture-posting-dummies.html


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## Umbongo (May 14, 2009)

Was this issue ever resolved in another thread ?


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