Jag IRS rear hub bearing play...

[Chris]

Will add this info having re-adjusted my near side front hub bearing after just over 12k miles.
The end float was giving me roughly with wheel and tyre in situ just over the max tolarance.
The correct tolarance is from my Haynes 242 xj6 manual, chapter 11, page 160, section 5, no 10.
All is good now and within 0.002 and 0.006 in (0.05 and 0.15 mm) with the wheel off .
Chris.

[Chris]

My tolerances are from Haynes manual published 1992 no. 478 Jaguar & Daimler 72-88 chapter 11 section 22.16

John,
the Haynes manual I have is no 242 and the tolerances are in Chapter 8 Final drive section, the page numbers
are 102 - 106 .
The page for the given tolerance is on 103 section 14, it got me confused because I was looking in chapter 11
/suspension and steering which shows your figures in section 17 for the wishbone outer pivot tapered bearing
end float .
I thought I was going madder but seemed to have solved the issue.
Chris.

[JON1D]

My tolerances are from Haynes manual published 1992 no. 478 Jaguar & Daimler 72-88 chapter 11 section 22.16

[Chris]

The hub bearing end float in my manual shows 0.000 to 0.002inch (0.00 to 0.05mm). This seems a very tight tolerance. This is well explained in this video on how to set up an end float. I have used the same method on the front bearing end float starting with 25lb toque then loosen by 1/4 turn.

https://www.youtube.com/watch?v=0RqlrnoiqnY

That's the method I used ,
the tolerances that I mentioned are from the Haynes Jaguar Daimler xj6, xj and Soereign 68 - Oct 86 .
The best way to measure the tolerances is to remove the hub assemblies and use a dial gauge, but if
in situ just do the 12 o'clock 6 o'clock method but take Into count that the measurements will be a bit
more exaggerated due to the wheel and tyre.
I do have about 1mm movement using this method .
Chris.

[JON1D]

The hub bearing end float in my manual shows 0.000 to 0.002inch (0.00 to 0.05mm). This seems a very tight tolerance. This is well explained in this video on how to set up an end float. I have used the same method on the front bearing end float starting with 25lb toque then loosen by 1/4 turn.

https://www.youtube.com/watch?v=0RqlrnoiqnY

[Chris]

These are the end float figures for rear hub bearing - 0.002 and 0.006 in (0.051 to 0.152 mm).
The front hubs have similar measurements.

[Bannon]

Thanks guys - the car has only done 1000 miles since build, so it can't be worn out.  I suspect it was a lack of familiarity on his part.  There is an XJ specialist near me,  so I might just drop in and get the rear end checked over.  I'll also take a look myself in due course.  I understand the play could be in the diff output shafts rather than the hubs.

[Chris]

The problem  is that if an advisory has been issued, it infers that it may need addressing at some point.
If the advisory is unjust because the inspector doesn't have the knowledge or information, it's not good,
so what I think is that "if in doubt" an advisory is issued !
I would add that I don't think it worth arguing with the inspectors as ultimately they have the upper hand,
not that is right .
Have had my mot's done though Thunderroad Cars and a couple of local stations.
My very local station that I currently use is the best as they are up on our type of old school tech and one
of the younger guys is getting the hang of it .
Hopefully this situation will continue, have only had one advisory after over twenty five mot's and that was
at at a station that doesn't operate anymore, that was for a cosmetic covering on braided front brake hoses.
His opinion that he didn't like these type of hoses and said it won't pass next time if they were still in place !
I did fit new rubber hoses before the next mot and passed with no advisorys.
As for the old xj suspension, front and rear there is ment to be slight play otherwise you risk cooking the
bearings if the tolarent is to tight, slightly loose is better than to tight .
I will get my old xj manual out and look up the figures today and post them on .
Chris.

[KevinW]

Having replaced these when I had my knock-on hubs fitted, I know its a bit if a PITA to fix, but might not even be the bearings.

However, if its a newbie MOT inspector he won't be aware that the Jag IRS has rather more play than a standard modern tintop, so it might be nothing to worry about. The issue has been discussed at various places on the web. e.g. https://www.jaguarforums.com/forum/xj-xj6-xjr6-x300-26/rear-wheel-bearing-play-how-much-acceptable-241036/

[Bannon]

I don't know much about these axles really - but I've been given an advisory on the  MoT certificate for 'slight play in the rear wheel bearings' - but isn't this normal?  Shouldn't there be a pre-set amount of play using shims?  Any advice on this guys?