1985 XJ6 cracks in rear hubs

Found identical surface cracks in both rear hubs. So far I have found four being sold for parts that had identical cracks in the same place. Have found that many pre 1985 Jaguars have these and they are thought to be imperfections from the foundry process. Finding replacements without cracks is a problem. Naturally nobody wants cracked hubs but are they really unsafe.
Would appreciate any input.

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‘Proper’ cracks are really unsafe - but whether it is possible to distinguish ‘proper’ from ‘harmless’ is uncertain…

On the other hand; hub failures are very, very rare - I can only remember one reported input over the years.

Frank
xj6 85 Sopv Europe (UK/NZ)
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Thanks Frank I appreciate the input.

Could you post a picture of the crack(s) I’ve not heard of this happening in a hub carrier.

https://www.google.com/url?sa=t&source=web&cd=1&ved=0ahUKEwiahcOcifvaAhXQm-AKHX3ZDioQFggKMAA&url=http%3A%2F%2Fwww.jag-lovers.org%2Fxj-s%2Fbook%2FHubCarrierCracks.html&usg=AOvVaw3hmI02PmzaNzEaNO5iy0A9

As the article notes they are not the best to have if they are fully visible through the casting. IF you have to continue using them the way to stop a crack from progressing is to drill a small hole at each end.
For normal use I would not be too concerned as it is a large casting with nice radii and Webb’s.

Thanks for the reply Robin. Here are some photos I took this afternoon. They are not visible thru the casting and you can’t catch an edge by using finger nail. I appreciate your input.

I would think these would be easy enough to repair…drill the ends…v out the crack and weld from both sides…then grind back. I would think most welding or machine shops could do the work…now cost may be another concern.

Cheers

Gary

Aluminum is tricky to weld and I don’t want to weaken the hub by cutting a V if these are superficial. Because I received four (4) used ones that all had the same “crack” in the exact same spot I am not so sure these aren’t casting imperfections. I won’t take the chance driving the vehicle until I am satisfied that these hubs are good and safe. Thanks for the reply.

Maybe you could sand the crack area and see if it’s a casting imperfection or a crack and how deep.
A magnifying lens would help.

This was also my initial thought when I red your first post.
I don 't think deformation would be a concern, especially where the crack is, and, if done properly, it would be as good as new.
En plus, this is not a high stress area.

Aristides

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I don’t really like the look of that crack - wonder how deep it is…

It is of course the flanges that takes the stress, and the crack is in the same area as that shown on the web picture - there identified a casting cracks/crinkles. ‘Yours’ may just be dirtied over the years making it more pronounced?

I wish I had kept the picture of the hub that broke - to see where that break occurred…

Frank
xj6 85 Sov Europe (UK/NZ)
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Thanks for reply’s. Not feeling entirely comfortable I have begun a search for any used hubs available without “cracks”. I do think that most owners don’t see their hubs because of the solid wheels. I am running wires so my hubs are readily viewable. I only found these “cracks” when we pulled a wheel to change a universal joint. I too have only ever heard of one hub that failed and that was on a Jag that was involved in a prior rear end collision.

I think I have them too, decided they must be from casting and wrote them off as Leyland quality.

I really think I am going to look long and hard to find any used hubs without “cracks”. Part of the problem is most Jag owners can’t see hubs thru solid wheels and if wheel is removed hubs are obviously very dirty. Almost convinced this is casting imperfection, BUT still not completely comfortable.

If you are not comfortable with them, definitely, absolutely the right thing to order crack-free ones. But in the meantime why not drive, as I’m sure many owners do and without faults we know of. Remember how much power these IRS can take, and how many bumps they withstand: gentle driving ought to be okay, right?
And isn’t it weird that my dirty, DPO’d XJ had very, very clean rear hubs with a thin layer of age-old crud, while the front was very full of brake dust. I’m sure nothing has been done to them, and all the brake pads and discs have been serviced at the same time. Were yours dirty?
Also while greasing hubs should be inspected anyways, they ought to look for cracks!

No David my hubs were not dirty when inspected. I run wire wheels so the hubs are clearly visible and they are relatively clean. I would agree with what you don’t see but once you do see, it does become unnerving. I really do think these cracks are common, but until I receive a lot more input from other owners I have to remain skeptical. Having looked at four other used ones with the same cracks in the exact same area and the fact that hub failures are not common does make me feel a little more confident. I will be diligent in my research.

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And with the same depth of cracking…?

A point here is that cracking may not be casting faults, but the hubs are made solid enough to hold - unless some other factors are involved.

I think it would be worth while to explore the cracks with a ‘dremel’. Apart from exploring the depth; a rounded tool would alleviate further stress cracking - much like a hole drilled in sheet metal to prevent crack progressing…

If indeed these are surface ‘crackling’ rather than cracks proper the depth will be shallow - and insignificant. Probing like this is harmless, and give you something positive to do - instead of plain worry.

The same hub was used throughout and the fact is that failures are almost non-existent. Adding that in the one recalled instance, the break might have been entirely unrelated and at a different place - one ‘may’ assume the risk is ‘negligible’ and worry unwarranted…:slight_smile:

Incidentally; the rear hubs stay clean of brake dust because the discs are inboard…

Frank
xj6 85 Sov Europe (UK/NZ)
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I have read about the issue on this forum, so check the archives

have numerous spares, and NONE of them have cracks

although a previous poster stated this is not a highly stressed area, I am not so sure, it would seem to me that road shock would be transmitted via the lower fulcrum arm attachment point

Right, that area sees the stress between wheel and bump (or is between the stressed areas). Maybe he can check how deep the cracks are as for him the parts should be close to worthless. Or beat them with a big hammer… whatever. I heard of axles and lower suspension arms breaking but couldn’t find broken carriers apart from Franks mention. I would never let someone weld them though, I‘d get crack free parts if I was worried!

Thanks for the response Frank. We did spray ether into the crack to clean out excessive dirt. While using a magnifying glass we then used a extremely small thin flat pointed tool to check the depth. There was very little, if any, penetration. We scribed the edges so that we could detect further expansion of the crack and mounted the wheel onto the hub. I have contact with two very reliable sources who are checking there spare hubs for cracks. I should have a crack free pair by the end of the week. Press in new bearings, mount the hubs, then the wheels, and move on.