The Haynes manual for this particular car I've been working on states that the road wheel nuts should be done up to 45ft/lb. This struck me as far too low. So I've done 'em up to 75ft/lb instead. After all, the wallahs down at National or ATS probably go even higher than that with their rattle guns. But seriously, 45ft/lb?? Can that possibly be correct?
wheel nut torque
Jan 07, 2018
96 Replies
Dunno. What do the manufacturers specify?
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It seems low compared to others listed on this site but as you?ve not given make/model/year you?ve rather limited the advice anyone can offer. I wouldn?t trust a third party manual for accurate information though.
Tim
45 lb/ft is standard for many older cars, any higher torque can deform the wheel nut location in the wheel itself and can lead to the wheel becoming loose and tearing off completely.
With the greatest of respects to Mr Cheerful: On a Mk 1/2/3 Cortina, Hillman Hunter, Nissan Bluebird, Talbot Samba, Nissan Micra and many more sheds, I just tightened up the nuts until it felt right. I still have the wheel brace which cost me a quid 46 years ago. A lot of money was a quid in them days.
That's what I've done in essence.
Yes, amazingly one pound bought 8 pints of bitter in 1972. Now it costs about 8 quid just for 2 f****ng pints! No wonder so many pubs are closing.
Newton metres? Urgh!! Might as well be in Chinese.
Very wise. Yes, I should have mentioned the car in question this time is a '66 Mk X Jag.
Yip! And oddly enough the wheels did not fall off.
30p a pint of lager in the rough end of the Number 3 posh pub in Blackpool, this in maybe 1978. This was a very posh pub! The amount of pubs closing down is tragic. Tennants/owners have lost their homes.
The standard wheel brace, used sensibly, will do the nuts up just fine, but over doing it or under doing it, can certainly be dangerous. Modern alloy wheel nuts are done up to levels of torque that would wreck the old steel wheels and snap studs.
Many people do not have any mechanical feel, and for them it is important that they have a foolproof way of doing the nuts/studs up to the correct tension, and checking them after a week or so.
If you used the supplied wheelbrace, doing them up as tight as possible may well be near enough, as they are vastly over engineered.
Once you use something that provides more than that leverage comes the problem.
Can you not find a genuine Jag manual? Or ask the owners club if they have that data?
I thought he said it would do 155mph, is he going to get it dropped out of the back of a C130?
I've got the factory manuals for the SI-III XJ6 which followed on from the Mk10. Wheel nut torque is given there as 45 ft.lb.
You might enjoy this rebuild then. (Slotting a V12 into a Mk10). It?s in 10 parts but I?m sure you?ll find the rest easily enough. Sadly seems to be lacking the final ?firing up? one.
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Tim
I'm surprised it's aerodynamic enough to have so high a terminal velocity :)
Well it would definitely be nose heavy, and the shape is quite swoopy, so it might get there. I would pay a tenner to watch the experiment live.
Seems that I must be gifted with that feel. However, I can remember taking the cylinder head off a Ford Zephyr 6 and shearing the bolt off in the block when I put it back. Using a small hammer, a small screwdiver and two trembling hands the bolt came out.
That's the V12 which had a service interval of 3000 miles, and needed it because the three twin choke carbs went far enough out of adjustment in that time to wreck the performance?
(Mate of mine was a Sales Rep when the XJS came out, "Salesman of the month" was given one for the month. he took me out for a spin in it when the service was due in 500 miles).
Used to go to college with a guy that worked for Pirelli in Burton. They had a V12 XJS on the test fleet, he said they were forever complaining about it only running on 8. Even on 8 it still did 120 something on the nearby test track between Burton and Derby.
Um, no, I don?t think so. It looks to have 2x6 branch manifolds and fuel injection although I grant you it?s not easy to see.
Tim
Pretty well all the V12s you'll pick up easily will be the later EFI version. Not that many carbs ones made.
It's one of those engines which is better on paper than in practice.
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