Hub Nut Spinning

[Lewis's Friend]

This is not a happy post....

I pressed my new bearings in today, which went very smoothly, and as I had a few hours before I was going out this evening I thought I may as well fit everything quickly.

Passenger side went fine.

Drivers side, while doing the hub nut up through the spare wheel, I felt the resistance drop off. I can now neither undo, nor tighten the nut. Not pleased at all.

Is there anything it can be apart from a stripped nut/shaft thread? I ask to save the car from rageful angle grinder and chisel hell which may descend upon it as for the first time since I've owned it I feel like giving it a righteous kicking...!

[v8s4me]

You'd really have to use a lot of force to strip one of those thread but anything's possible.Maybe either the axle thread or the thread on the nut was already weak? Try to get a lever behind the nut; if you can get some purchase on it try undoing again. Failing that you'll have to cut the nut off carefully and hope it is just the thread on the nut which has gone.

[GreenV8S]

Perhaps this is a good time to count yourself lucky, because there are far worse ways for that thread to fail - it is potentially all there is between you and a life-altering experience.

I imagine it would be possible to get a nut which was oversize for the thread but the correct pitch, but I'd have thought you would have noticed that pretty quickly. I can't see any other way for the nut to spin without sheering the threads, which ought to be extremely difficult if the nut was manufactured correctly. If you can put any tension on the wheel then Joe's suggestion to try to catch on the remains of the thread is your best bet.

Not to worry you, but how confident are you about the nut on the other side?

[TVRees]

Did you reuse the nuts which you removed?
If they were new nuts, maybe you can supply some details of where you bought them.

[phillpot]

Just how long was the bar you used to tighten it?


With some careful drilling and gentle chiseling you should be able to get the nut off, if Joe's idea doesn't work, then asses state of the thread on the shaft.


Can never remember, is that left or right hand thread on that side?

[Lewis's Friend]

Hi guys, thanks for the feedback - I've calmed myself a little now and realised that there are far more imporatant things in the world than a stripped thread! And having it fail at speed would probably have been a lot worse.

To tighten the nut, I just use a breaker bar. I'm a bit of a weed, so a little extra leverage seemed like a good idea, but I'm rather surprised I've managed to strip such a large thread. On the drivers side, the shaft thread is a normal right-handed one.

Thanks for the tip of trying to make the threads bite with a bit of pressure on the nut; I should have thought of that myself as something to try first.

I bought the bearing kit from TVR Parts, and they came with new nuts, so I used them. I don't want to blame the bits though until I've got it apart and found out what failed. The bearings themselves are SKF, so a good brand. I don't think the nuts are marked, but one would hope they are of decent quality too. I'll update this when I find out more though.

[phillpot]

Let me know if you need it

[Lewis's Friend]

phillpot said:

Let me know if you need it

You're a kind man, I may well be in contact depending on how things go...!

[GreenV8S]

Lewis's Friend said:

I'm rather surprised I've managed to strip such a large thread.

I suggest you try to estimate how much torque you were applying (i.e. by multiplying the force/weight you were applying by the leverage) and find out how much torque the nut was supposed to be done up to. If you were over-torquing it then I think it's safe to assume that's why it failed. If you weren't, you need to look further to make sure you understood why it failed.

In general, torquing fasteners as tight as possible using a big bar is not a good idea.

[phillpot]

Lewis's Friend said:

You're a kind man ...!

You don't know the price yet! ....



Tightening torque is 250-290 Nm or 185-214 lb ft in old money.

[phillpot]

Need your address Jon

[Lewis's Friend]

Thought I should update this quickly, now I've cut the nut off.

It was the shaft thread that failed, so no dodgy bits sent from TVR Parts - their good name remains intact!

And Philpot has been a gent and sent me a new stub axle, so it should be back on the road soon and I will be more careful tightening nuts up in future!

[GreenV8S]

What's the state of the thread on the other side, and do you know what torque it's been done up to?

[Lewis's Friend]

GreenV8S said:

What's the state of the thread on the other side, and do you know what torque it's been done up to?

I'm going to borrow a torque wrench from work that goes up to 350Nm so I can do both sides properly. Better safe than sorry...

[phillpot]

GreenV8S said:

What's the state of the thread on the other side?

I've got that one as well

[Barkychoc]

I have a 1m breaker bar. Anything you can't undo that beast does it like it's not there.
I smashed 3 sockets with it a while ago undoing cylinder head bolts - they probably weren't great quality but the point is it's surprising how much power you can get with a long bar.

I also have a torque wrench 1m long really heavy and it goes up to 550lbft - you can hardly pick the bloody thing up!

[GreenV8S]

Barkychoc said:

I have a 1m breaker bar.

That should do the trick, as long as it's small enough to fit inside the scaffolding tube in case you need to apply any serious torque.

[zombeh]

I do hub nuts by applying a force of one Steve most of the way down an 18" bar, so ~1.25SteveFt which is ~200lbft

[Kitchski]

I suspect it's probably a thread that was already damaged in the past. We see loads of them. Stick a sharp new nut on there, give it the welly and eventually it lets go.

I think I've got a spare stub axle somewhere.

[Buzzlt]

You wouldn't want them coming loose round Spa would you terry ??