Hubs beware

[Henry Harris]

Please beware.

I had noticed a light grating noise regularly in time with road speed, on anything that involved a right-hand turn of any degree. The noise was neither there or extremely light on the straight-ahead nor when braking.

On investigation it has been found that the nut holding the left-hand rear hub to the driveshaft was rotating freely. The thread had been stripped on the driveshaft itself and on the nut. The nut appears to have a pinning hole at its edge (the curved bit). On mine, there were several other holes on the body of the nut. On further investigation, the one and only pin through the body of the nut had broken. I was fortunate for the wheel not to have dropped off completely. A conclusion was that with all that drilling and pinning had weakened the threads.

A disaster waiting to happen!

Have fellow PHers any comment on this pinning or related matter?

I hope that I have the terminology correct.

[TVRleigh_BBWR]

Problem is they can come loose, when not pinned also.
What they should have done is make the shaft, and fit an nut and use the mark on the shaft to drill the new nut in the same place.
Either that or use a castle nut, so the pin goes in one of multiple groves in the end of the nut.

It has been reported a few times of wheels coming off. so they should be checked regularly

[leorest]

The best solution would be a left hand thread but in the real world of manufacturing on a budget we have to make do with a Nylock nut. Unfortunately Nylocks are not designed to be re-used

How much would it cost to get a small batch of all metal deformed thread lock nuts made? (k-lock)
http://en.wikipedia.org/wiki/Distorted_thread_lock... “Due to the elastic nature of the deformation the nuts can be reused indefinitely”

There have been many discussions (I avoided the pun) over the years pontificating over whether to pin, liquid threadlock, or fit a new Nylock nut. The most consistent message is to check them often. There’s another pun narrowly avoided.

Out of interest what are your options if the thread on the shaft is sha... damaged? I believe the spline is unobtainable.

[grahamw48]

My nearside rear wheel came off at 90mph.

Check your nuts regularly !

There needn't necessarily be any warning noises (none with mine), but if one of your wheels appears to stick out slightly further than the other...check it !

[Jonny weggie]

Henry you must have very acute hearing, especially over the exhaust noise. I cant even hear the wife yaking [great] never mind slight rumbling noises.

jonny.

[mrzigazaga]

I had two of the nuts holding the diff plate on missing and the others were only finger tight..Im glad rooodboy spotted it..The knocking and fishtailing has stopped now..nearly had zigazaga pate on the menu of the BBWF..Perhaps checks should be made on all the nuts and bolts on a regular interval.

[JR]

Henry Harris said:

A conclusion was that with all that drilling and pinning had weakened the threads.

A disaster waiting to happen!

Have fellow PHers any comment on this pinning or related matter?

You are probably right. As TVRL mentioned the best solution is to use a castelated nut and pin and get a garage/yourself to do the job properly and not keep drilling new holes.

[Henry Harris]

Jonny weggie said:

Henry you must have very acute hearing, especially over the exhaust noise. I cant even hear the wife yaking [great] never mind slight rumbling noises.

jonny.

I can see I'll have to offer my services for problem root cause detection.

Edited by Henry Harris on Tuesday 22 February 16:36

[TVRleigh_BBWR]

leorest said:

The best solution would be a left hand thread but in the real world of manufacturing on a budget we have to make do with a Nylock nut. Unfortunately Nylocks are not designed to be re-used

How much would it cost to get a small batch of all metal deformed thread lock nuts made? (k-lock)
http://en.wikipedia.org/wiki/Distorted_thread_lock... “Due to the elastic nature of the deformation the nuts can be reused indefinitely”

There have been many discussions (I avoided the pun) over the years pontificating over whether to pin, liquid threadlock, or fit a new Nylock nut. The most consistent message is to check them often. There’s another pun narrowly avoided.

Out of interest what are your options if the thread on the shaft is sha... damaged? I believe the spline is unobtainable.

I think some of the SEAC's had left handed threaded shafts.

Not heard of anyone recommending liquid thread lock, not sure if it's good enough for the hub nuts due to the reverse forces.

Re the threaded shaft, I was looking at one the other day that has a shagged thread, and was thinking this could be drilled out, and the tapered shaft internally tapped and a thread shaft fitted, once fitted the non nut end could be welded so the shaft don't come out.

[leorest]

TVRleigh_BBWR said:

...Not heard of anyone recommending liquid thread lock, not sure if it's good enough for the hub nuts due to the reverse forces...

There are grades of threadlock which are like welding on - don't use them. I used a drop of light duty stuff on just a couple of threads - it was very difficult to get off. Ultimately you have to make your own decision.

[TVRleigh_BBWR]

leorest said:

here are grades of threadlock which are like welding on - don't use them. I used a drop of light duty stuff on just a couple of threads - it was very difficult to get off. Ultimately you have to make your own decision.

I used loctite 243 on all the engine bolts that require thread lock, most of the bolts on the racer that don't have nylocks, and not had a problem undoing them.

http://www.bearingboys.co.uk/Loctite_243_Medium_st...

[leorest]

TVRleigh_BBWR said:

I used loctite 243 on all the engine bolts that require thread lock, most of the bolts on the racer that don't have nylocks, and not had a problem undoing them.

That's similar to the one I use but remember with a larger thread it will require higher torque to breakaway as there's a lot more surface area and less mechanical advantage. On smaller bolts 243 is no problem to undo.
-
A deformed thread all metal locknut (like the ones holding the other end of the driveshaft to the dif) would be the best solution as (unlike nylock) they are OK to use almost indefinitely.

[adam quantrill]

I don't think there's a problem with drilling the nuts multiple times, as long as the holes aren't too close together. The real problem with Henry's situation is that the threads all got stripped off - no end of loctiting etc will fix (or prevent) that.

Can the stub axle be built back up a bit, machined and then re-threaded so you can use the original nut type again? I had a stub axle machined for about 15 quid to make the shoulder square, so I would imagine it would be around the same cost, plus the welding to add more meat.

[TVRleigh_BBWR]

TVRleigh_BBWR said:

I used loctite 243 on all the engine bolts that require thread lock, most of the bolts on the racer that don't have nylocks, and not had a problem undoing them.

http://www.bearingboys.co.uk/Loctite_243_Medium_st...

Loctite did stop it coming off again, and was not too tight to get the nut off, but the damage was already done when it was loose see
http://www.pistonheads.com/xforums/topic.asp?h=0&a...

[pk500]

will be modifying mine after this i think tighten the bolt up then drill hole and split pin might be a good idea!

[grahamw48]

That looks familiar. (not mine)

[pk500]

what the colours or the wheel off?

grahamw48 said:

That looks familiar. (not mine)

[grahamw48]

I was doing 90 in the outside lane of a dual carriageway in my 400SE when the nearside back wheel parted company in similar fashion.

[wooly350i]

adam quantrill said:

I don't think there's a problem with drilling the nuts multiple times, as long as the holes aren't too close together. The real problem with Henry's situation is that the threads all got stripped off - no end of loctiting etc will fix (or prevent) that.

Can the stub axle be built back up a bit, machined and then re-threaded so you can use the original nut type again? I had a stub axle machined for about 15 quid to make the shoulder square, so I would imagine it would be around the same cost, plus the welding to add more meat.

I had a shagged stub axle thread a while ago off Paul gsx500 and asked about getting it fixed but didn't bother in the end but my theory would be to turn the stub down assuming it can be fixed into a lather then wind a new thread onto it followed by a substantial sleeve threaded on the inside to fit the shaft and threaded on the outside to take the nut or weld a sleeve over the turned down stub,a lot of work when I could buy philanthropy off him.

[adam quantrill]

TVRLeigh_BBWR said:

Re the threaded shaft, I was looking at one the other day that has a shagged thread, and was thinking this could be drilled out, and the tapered shaft internally tapped and a thread shaft fitted, once fitted the non nut end could be welded

This has got me thinking - could the end of the stub axle be tapped and a bolt fitted on it, wih a big washer?

So if the nut comes undone, the wheel doesn't come all the way off, but it will make a horrible noise, and you won't lose the wheel or hub nut onto the road. Then you'll have a chance to recover the situation by screwing the hub nut back on, or have the car recovered more safely.