C5 Mk1 - Problem Fitting Rear Wheel Hub Due To Rotating Stub Axle

[aspire_helen]

Hi

 

Summary:On try to torque down the bearing nut, the whole stub axle rotates. This is on a genuine Citroen trailing suspension arm.

 

Finally got around to replacing a rear trailing suspension arm . A while ago I bought on Ebay a genuine Citroen arm assembly (5175X8/9) going cheap, from a Citroen dealer presumably getting rid of old stock. It has the advantage of having the pivot bearings already fitted and adjusted. However, it has the draw back of coming without a hub bearing.  It does come fitted with the stub axle - and there lies the problem.

I have fitted the arm OK (bit of a struggle to align the pivot bolt), and expected the fitting of  an after-market hub to be the least of my problems.  However, on trying to torque down the bearing nut I find the stub axle rotates. Now I am in the situation where I cannot torque it down or unscrew it - the axle simply rotates.

I assume something is supposed to prevent the axle from rotating. Haynes mentions when fitting a new stub axle ....."align its spines with those of the trailing arm".  However, I think it reasonable to assume that the Citroen assembly would come with the stub axle ready secured. I can feel splines deep inside the hollow stub axle, and thought these may be to locate a tool to counter the nut torque, but evidently not.

Anyone got any ideas.

Helen

[paul.h]

The service box procedure for replacing the stub axle does not mention the splines but it is inserted after checking the circlip is fitted to its inner end, greasing it with G6 grease, then knock it in with a hammer and bronze drift, then use a G clamp/spacers to tighten/pull it in further. So it is just a tight fit, maybe tapered like a track rod end. The hub nut is done up to 250 Nm so it has to be a tight fit to stop it turning. Removal of the axle is a reverse of this, using the G clamp/spacers to push it out, then the hammer/drift to get it fully out.

 

You could try applying a G clamp to the inner end of the axle with an arrangement to the other side of the suspension arm which gets around the hub or maybe tapping with a heavy hammer but being careful not to damage it. The parts diagrams show the axle has slots cut in at the threaded end and if so, maybe a bar/screwdriver could be used in them to stop it turning. I would think once the nut is tightened the axle will be pulled fully in place.

[aspire_helen]

Hi Paul

Thanks very much, I hoped you would reply. Didn't get much sleep last night with the heat and worry!! I will look at it again this morning and get back to you later.  

 

In the meantime can you quickly confirm just one thing.   In which direction is the stubaxle knocked in? ie when facing the wheel do I drive it in from the hub side (outside), or the reverse from under the car (inside)? With the hub fitted it is not easy to tell, and Haynes does not specify.

 

Helen

[paul.h]

The stub axle goes in from inside. Then when the hub nut is tightened it pulls the axle further to the outside.

[aspire_helen]

Many thanks again Paul.

On that basis it would appear that all that is needed is to stop the axle rotating while tightening the hub nut. I notice that looking deep inside the hollow axle from the inside (ie from under the car) there are 12 pointed flats (like a socket) which take a 19mm hex-drive/allen key - just the ticket!

But if it were that "simple" why does Service Box not mention this?! Currently, the axle is rotating at about 30Nm torque - ie very low. I will need to source a long 19mm hex drive, or perhaps a long bolt with 19mm AF will do. I would then hope that the axle will bed in and hold long before the full 250Nm!!!

 

I'll let you know. Today I focused on finishing off replacing both rear suspension arms, and getting the car back on all 4 wheels - now successfully done - phew!. I don't need the car for a few days so I will attack the stubaxle problem separately.  I am also getting intermittent "ABS faulty" warnings from one of the ABS sensors - nothing is ever easy on a C5!

 

Ref Service Box. Are the maintenance procedures available to all for free (as with the parts catalogue),  or are they one of the pay-for options?

 

Helen

[paul.h]

I got the service box on a set of 3 dvds through ebay about 5 years ago. The last dvd version was about 2013 and new versions since then are only on-line. The on-line version can be seen by paying on the service.citroen site after registering but you can see just the parts diagrams free. In our family we now have a 2016 Cactus which seems similar to the previous 2010 C3 for brakes, so I will try paying for procedures/torque values so I can give them a clean.

 

Wheel bolts often are 19 mm AF but not Citroen ones. Toolstation sell high tensile bolts up to M12 x 70 mm (£1.34 for 5) which I think will be 19 mm AF and you would then need a couple of nuts to lock together on it or better to weld on for your socket.

[paul.h]

This C8 topic mentions a download but I did not understand the bits about virtual machines,etc. http://www.citroen-owners-club.co.uk/citroen/topic/23950-c8-workshop-manual/

[aspire_helen]

Thanks again Paul.  I've ordered an extra long (10cm)  19mm allen shaft and socket with 1/2" drive for approx. £7 on Ebay. It has to be extra long - the flats inside the stubaxle are between 5 and 8 cm deep.  I already had a set of such sockets but the 19mm was just too short to reach!!

 

By the way, I am going to start another topic asking how to shim the suspension arm pivot TRBs (taper roller bearings). 

 

Helen

[aspire_helen]

Paul

The 19mm allen key worked a treat to stop the stub-axle rotating. I haven't fully torqued it down yet because I have an "ABS system faulty" warning, likely to do with the ABS sensors in the suspension arm. I will post a new topic on that.

H