S-type,X350,XF Wheel stud breakage and solution.

[J44EAG]

Very occasionally wheel studs sheer off. This is most annoying and is usually caused by someone over tightening a wheel nut previously.

Sadly these studs are not dealer supplied as replacement parts. One can then be faced with having to buy a complete new hub and bearing cartridge. For interest bearing units for the above cars cost from £66 upwards on ebay. On top of that would be around two hours work to fix. Sounds a lot?

To remove a front wheel bearing cartridge will often mean stripping out the the brakes and pads but more importantly the vertical hub bearing leg. The bearing cartridge corrodes into the hub carrier and a bench press is needed to push out the bearing cartridge and break the immensely strong electrolytic bi-product that bonds the aluminum carrier and steel leg together as if welded! In my recent experience, bearing removal has taken between 3.5-4 tons of pressure before the bearing is free of the carrier and breakages of the carrier due to the high forces involved have been known. That`s a lot of work, risk and expense just because one wheel stud has broken.



It is possible to avoid irritating future stud breakage expenses if and when you next have to have a wheel bearing unit replaced on your car. Typically one can expect the near side front bearing to becoming to the end of its useful life at around 85-90k miles. A new unit comes complete with cartridge case, internal bearings, ABS reluctor ring and five new studs fitted to a new wheel mounting flange. I would suggest you might ask your garage to let you have the old wheel bearing cartridge back when you collect your car. You can then salvage the studs by carefully manually drifting them out of the hub flange or using a bench press if you have the use of one. One can then keep them in a safe place for replacement use if you have the misfortune to suffer broken studs.

On the early S-type hub carrier, there is a one inch hole sited in the 12 o`clock position which would allow a broken stud to be drifted out of the hub flange and through the leg. A replacement stud can then be fed through the hole in the leg and located in the vacant splined drilling in the hub flange. The replacement stud then only has to be driven fully home and you have a fully serviceable stud set again for no parts cost and only around half an hours work/labour. In this image (turned 90degrees to get it to site our site pixel limitations) the "hole" is to the left of the picture centre.

I suspect that a similar access hole in the hub carrier can be found on MY52> S-types and XF models.

I need to investigate whether a similar "hole" exists on the rear suspension hub carrier. It would be nice if it did. I need to examine the situation at the rear of the car and hope to be able to report back shortly.

Mike

[Azure123]

I see you listed the 350 in the vehicle's that have wheel studs. Did jaguar move over to wheel bolts for the 358 because of this issue do you think?

Steve

[J44EAG]

I wasn`t aware of that. Strange if they did. See bottom paragraph.

In perspective breakage is very rare but some tyre bay gorillas can torque up huge figures after they have eaten a couple of nasty burgers for breakfast. At that point the damage is done.

After straining a thread it may take quite a number of tightening applications over the years before the issue rears its head. Over tightening causes a stud or bolt to pass through the elastic range of the material (thread returns to unloaded length when in the elastic range as load is removed) and then enter the plastic range. As load is applied the thread stud stretches but when load is removed it does not return to its original length. Carry on loading and the thread "necks" or thins in cross sectional area before reaching ultimate tensile strength. At that point the thread is work hardened, strong but has little malleability or ductility remaining. Load the thread further and the material will lengthen again slightly before total failure occurs. Equate that occurrence and description to the breakage of a wheel stud or bolt.

A tensile sheer is a tensile sheer whether it is to a threaded stud or a screw in bolt.
I suspect any design change of design for X358 may have been due to it being thought that it is easier to fit a screw in thread to a flange rather than by lifting a wheel rim and tyre onto flange mounted studs.

I now have to shift and modify my knowledge stance in regard to this ebay hub and others advertised similarly. By genre, S-type X350 and XF are generally listed showing stud type flanges but close scrutiny appears to show that studs types ARE not fitted to X358. So I have been incorrect assuming studs passed to X/358 models from S-type. Sorry about the bum steer on that, guys. It would definitely seem that wheel nuts with "integral bolt" are used. I would think they could be removed rather more easily in the event of some component failure occurring.

Interesting and deep traps for the unwary including me.

Mike K

[Azure123]

Sorry Mike I dropped a real clanger here and had a senior moment or as my wife says one of my many confused.com moments. My 358 has wheel studs as you correctly stated and the wheel is secured with wheel nuts. Don't ask me why I suggested Jaguar had moved over to wheel bolts for the 358. I must have momentarily convinced myself my new Jaguar wheel nuts were bolts when of course they are not, see pic. Sorry again for a un researched comment. I'm going to lie down.

Steve

[J44EAG]

No problem, Steve.

I did start looking particularly on ebay for any differences in late model X350/358 model wheel bearings. Oddly listings for the typical stud types which I understood fitted all S-type, XF, X350/358 models became rather obscure as I began looking at the later cars. Cross referencing in one instance said that 358 models were not covered by the standard stud type applications. My reaction was to surmise that due to rarity of generic use of "358" caused the parts cross match search facility to misfire as a data error. What is perhaps evident though is that cross reference sources are not always to be relied upon where multi model applications exist or there is a degree of general haziness in generic nomenclature.

That having been said, I think we can all be pretty certain that the stud type bearing cartridge units are universal and that still goes for even MY14 year cars.

Obviously anyone needing to fit a new cartridge bearing to any model and year should always spend a few moments ensuring that the typical stud unit is correct for their car. I suspect that in 99% of cases the standard type we know so well will be suitable.

I`m glad you bought up the subject of the 358 on this thread. The good thing is that it would appear that the standard bearing is unchanged and that rules out any possibility of confusion at a later date. It also rules out an oddball bearing in the market and the possibility of 358 models having special over inflated prices for a special part!

Thank for your input, Steve.

Mike

[Azure123]

Mike, thanks for the detailed over view on the subject and acknowledging my error didn't cause to much offence.

In the same area of the car you have spoken of I want to fit new front discs and pads but I'm struggling to find out how to remove the retaining rings/washers on 2 of the very studs you mention which look like the only method of securing the front disc to the hub flange. Are these round clips, which look like they push over the threads of the stud and fit right up to the hub face, designed to be sacrificed when removing the disc?. These special clips dig into the thread and stay in place due to little tangs on the inside diameter of the washer. Once the calliper is removed and the carrier is removed the disc remains in place because of these two little washers. I wonder if they need to be levered off and somehow forced back down the shaft of the stud and then hopefully allow the disc to come free.

[J44EAG]

I and probably others will be familiar with these push on spring type stud clips which are used on some cars to hold the disc against the hub flange when calliper and pads are renewed.

This is the first time I have heard of clips being used and indeed I have not seen them used previously on a modern Jaguar. They certainly don`t appear on an S-type. May be others will be able to confirm if these clips are a later modification.

Being almost certainly of a spring type clip there may be an "official" removal tool but I doubt it. Teasing with a screw driver or other suitable implement to disengage the tabs and allow removal will be required when new discs are to be fitted. The clips may or may not survive for a second or further attempts at refitting when disc changes are necessary.

As to their true worth, these clips in reality would do little more than act as a convenience holding the disc securely against the hub flange. Once callipers and pads are refitted not to mention the road wheel, their function would become rather academic. The X350/8, XF and later pre facelift onwards models have 326mm diameter front discs whereas the early S-type has only 300mm discs. May be the larger discs are more difficult to reline when pads are fitted than early S-types. R models have different discs and much larger 4 pot callipers so I can imagine they might be more of a hand full at brake service time unless those clips are in place to help steady discs. Just a thought on why those clips are in evidence.

If you can lift the tabs and remove the clips intact for further use, I see no reason why they should not be safely re used. I have fitted similar items on other cars in the past and remember pushing them onto the stud then driving them down the tread with a long thin tubular socket. A short length of steel or copper pipe of a suitable internal diameter would also serve the purpose. A good shove with the socket or pipe would drive the clip down the stud and you would then be back where you started with the clips refitted. Job jobbed.

If the clips needed to be replaced, I`m sure you would find those items in almost any good high street motor shop. I think I may have seen some in ready packs in Halfords. Otherwise a Main Dealer will almost certainly have them in stock.

My own personal view is that these clips are a rather superfluous item and not refitting them is hardly likely to cause brake squeal or other brake problems. Once the road wheel is back in place the disc will be unable to move as as previously stated and the practical need and value of the clips non existent.

Hope that helps, Steve.

Mike

[Azure123]

Thanks Mike, really useful over sight on the merits of these clips. Interestingly the spring steel clips are not used on the rears, only the fronts. I'm fitting new back plates as well which I had powder coated as the originals are made from an aluminium type sheet metal which just goes manky after 6 years in my case. These should be straight forward as they simply rivet to the base of the suspension system. Couple this to my newly refurbished 19" Jaguar Custom wheels new discs, pads and already painted callipers (black) will achieve the tidy look I'm after.

Thanks again

Steve

[J44EAG]

Nice, Steve.

The correct rivets from Graham at Black Country Jaguar at six for £10.24 delivered and at the cheapest price I can find.
http://www.ebay.co.uk/itm/380991428090? ... EBIDX%3AIT

Full details for fitting of rivets, front ball joints and front wheel bearings to S-type, X350/8 and XF models can be found in the S-type BB suspension section under the heading of "Spring is here as so is the long overdue maintenance". For those not having seen this thread, this details what is required when any of these parts need replacement. Plenty of photographs illustrate the work in progress.

New dust shield are available from under £6 each from British Parts. Other sources appear rather more expensive.

The ali shields to split, tear, crack and rot quite quickly in adverse conditions. Indeed I scrapped a couple the other day from a pair of legs I bought in for reconditioning. The shields fell to bits as I removed them. The part is not one of the better ones to be found on the car.

Mike

[jeff1954]

Hi Steve. Those wheels look the business.

Jeff

[oldtimer]

Hi Mike and Steve,
The clips to which you refer are simply convenience clips. All they do is hold the disc in approximately the right position while work is in progress. Remove them by cutting and tearing off with a pair of wire cutters. I have a packet of them in the Workshop and don't feel inclined to get the part no tonight.

My 03 S type has had them from new. They are used on all four wheels, as for the number on each wheel, that is Hobson's choice. You could get by using none but I chose to use 3 per wheel.

Oldtimer

[Azure123]

Hi Oldtimer, I thought myself these spring steel clips would be difficult to work back up the stud shaft and considered the force them back enough to get hold of them and tear/split them and then just use new ones.

steve

[oldtimer]

Steve,
They are a bit awkward to get hold off. They can be wound back a bit with a small screw driver to get the snips in. Giving the disc a yank also eases the clip back a bit. You have to Gorilla it off - not very technical but needs must.

You may be interested to know that I have painted one wheel stud tip of each hub red and use that as the master stud. I have permanently marked both the discs and the wheel rims to ensure that they are reassembled back into the position in which they were fitted. The object of this is to reduce the risk of building in a problem that was not previously there. Like an out of balance problem. I also have each wheel location marked on the inner rim i.e. F/N/S etc. Many might say just a "silly 'ole git" May be so but I have no problems !

I periodically take the wheels and discs off, and remove the pads for cleaning. It is crucial that the surfaces of both the hub and disc mounting face are impeccably clean. I use a 1/2 inch square by about 8 inch long stone dipped in white spirit to remove any corrosion. Use some freeze spray degreaser. I have found that by flashing over the clean hub face with a bit of grey primer and then the very very thinnest wipe over with copper slip keeps the corrosion at bay.

And finally, I take the wheels off and take them to the Tyre House for new tyres so that the varmits cannot attack the wheel nuts with a windy gun (impact wrench) or damage the sills with the trolley jack.

Hope that helps a little

Oldtimer