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Interesting Morning

If threads are rusty you twist the stud rather than stretch it. It,s difficult to overtighten if you use the supplied wrench.

I.... IMO I say follow the manufacturer's guide.....
Here's the manufacturer's guide:
ScreenHunter_37 Apr. 29 10.58.jpg

This page is from the Owner's Manual. They say never to grease.
I have experienced over the years that lack of grease/oil on the studs lead to corrosion. This necessitates cleaning the threads from time to time in order to get the nut to contact the wheel at all at the prescribed torque. This links in with Frank's comment.
I have always lubricated the studs (and mating surfaces) with ceramic grease, and tightened to 130 Nm and never sheared a stud, or destroyed a nut. If I tighten to 130, then after a couple of miles driving, 4 of 5 nuts are too loose. After retightening, and driving another few tens of miles, again a few nuts will move a bit at 130 Nm.
So, I always recheck torque 2 times, and if changing at a tyre place (when new tyres), I ask them to leave them at the loose side, and I bring along my own torque wrench.
 
Very interesting post uHu.

Quite a few different opinions and experiences here, so really hard to decide what you do.

I'm inclined to go with the manufacturers guide, although 130nm seems a bit high. I'll ask the Toyota tech what they go to as another point of reference
 
I see both sides of the grease/no grease comments and there very valid thoughts behind them all however, IMO I say follow the manufacturer's guide. Let me throw this in the mix and I will use Clive's example which makes very good sense.

What if the manufacture decides that 25ft/lb is needed for 'x' bolt to clamp a wheel on, and research shows that 30ft/lb on clean DRY threads will (after losing some torque to thread resistance) leave the correct 25ft/lb.

This now means with WET (enter lube choice here) the wheel is exposed to a greater clamping force, now at 30ft/lb and beyond manufactuers spec. No science behind this guy's just a little deeper thought.

Regards

Dave

Can't fault the logic there Dave, and it may be true for trucks 5 - 10 years or so old. Trouble is, after 22 years, the range of scenarios on different vehicles must be very wide indeed.

I've had many old cars through my hands years ago, and some of them have been in a right state before I got them properly serviceable. The example of exceeding the torque just to get the wheelnuts off, was no eggageration on a couple of occasions.

I've changed studs for no other reason that the old threads had literally rusted away!

I can see the reasoning for not greasing, but over the years, I've come to the conclusion that the pros outweigh the cons. It's JMO of course and each to their preferred, but cranking them up like some of the tyre workshops do, is really asking for trouble.

Who knows what caused Tony's failure, but a total loss of all 6 in a matter of seconds is not acceptable, and I'm sure Tony would agree.

One shearing should not cause all the others to fail, so it must be down to abuse at some stage of its life. No suggestion here that it's Tony, but so many of our trucks are circa 1/2 million km which means multiple tyre changes, and multiple opportunities for tyre fitters abuse.

Even they are probably ignorant of the danger they pose, and for one reason only, because they think it's safer to be too tight, rather than too loose. I don't blame them, but when you come to a vehicle needing a 6 foot long thick-walled tube to shift them, something's wrong in the thinking, somewhere.
 
Here's the manufacturer's guide:
View attachment 124901
This page is from the Owner's Manual. They say never to grease.
I have experienced over the years that lack of grease/oil on the studs lead to corrosion. This necessitates cleaning the threads from time to time in order to get the nut to contact the wheel at all at the prescribed torque. This links in with Frank's comment.
I have always lubricated the studs (and mating surfaces) with ceramic grease, and tightened to 130 Nm and never sheared a stud, or destroyed a nut. If I tighten to 130, then after a couple of miles driving, 4 of 5 nuts are too loose. After retightening, and driving another few tens of miles, again a few nuts will move a bit at 130 Nm.
So, I always recheck torque 2 times, and if changing at a tyre place (when new tyres), I ask them to leave them at the loose side, and I bring along my own torque wrench.

I can't even start to suggest not following the manufacturers instructions, that would be negligent. Clean and lubricated are two different things, and I take the point that a lubed thread may well end up with an overtightened stud.

I've never used a torque wrench on wheel nuts/bolts in my life, so maybe I've been at fault all this time, but as said, I've never sheared a stud or had one come loose, so maybe we're all getting a bit paranoid.

Maybe if I had a failure like Tony did, I'd get paranoid myself.

Good discussion though, now I need to take stock and decide whether to change my wayward ways...
 
I am indeed very paranoid at this moment. I'm not at all sure that it's safe now at all, so as previously mentioned, all the other studs will be replaced, and until then I will be checking them weekly with a torque wrench.

I just can't afford another incident.
 
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Good discussion though, now I need to take stock and decide whether to change my wayward ways...


Because i have never used a torque wrench on my 19 year old studs i think if i were to start now i would first use the wrench to find out how tight i had habitually been going and stick with it , albeit accurately . My assumption being that a stretched stud will effect torque in ways i don't understand .
 
130nm must be for steel wheels 'cos it's 103nm (76lb/ft) for alloys which can be exceeded relatively easily even with the standard brace. When I eventually started using a torque wrench after shearing 2 studs I reckon I must've been torquing the alloys up to well over over 100lb/ft in times past. They are certainly much easier to remove now they're correctly torqued up! I use anti seize compound on the studs (copper slip) not bearing grease, there is a difference.
 
Had a puncture on my way to the barracks one day, changed the wheel and continued on my way, late and in a rush. Off on exercise for 2 weeks. Got back, drove home 55 miles. Loaded the truck up and set off for Russia. Several hundred miles later, just past Hanover on the autobahn doing about 70mph , BANG!!! and the left rear of the truck dropped. As it slewed across the autobahn I checked my rear view mirror to see what was going to hit me, and saw my steel split rim following me down the autobahn. That hit me. It was one of the few stretches that's 3 lanes and I was in the middle lane, so at least I had space. The car fish tailed back across and I reversed my lock to counter the massive oversteer. The central reservation flashed by the bonnet as I threw the lock the other way, then back again. The fishtail gets bigger every time and now I know I will lose it so I hit the brakes. I finally stop, remarkably still upright, in the middle lane and facing the wrong way. It's time for new underpants.

I forgot to recheck my wheel nuts and, some 600 miles later, it caught up with me. Lucky to survive.
 
Years back, I used to check the wheel nuts on my HGV (8 legger), every morning before pulling out of the yard, the forces involved when manoeuvring one these heavy beasts on building sites are enormous. The wheel nuts tighten anticlockwise to help prevent loosening, and there was never any lube, the threads were wire brushed though. Despite never loosing a wheel, on one occasion I did notice some staining around the inner rim on a twin set on one of the rear axles,

The boss's investigation showed that the wheel nuts had not moved (markers), but the wheels were loose enough to rub against each other. It transpired that the mating surfaces of the two wheels and the hub face had not been cleaned properly during the last tyre change at a local tyre shop, the mud or whatever had been trapped between the wheels and mounting faces had ground down leaving the wheels loose enough to move about, the nuts had stayed where they were. I cannot remember how much but, the cost for two new rims and a brake drum, a new set studs and nuts was unbelievable.

As per @clivehorridge comments about age, perhaps the build up of fine surface rust allows the wheel to be mounted on an unstable surface, the wheel now can move about enough to grind the rust away leaving the wheel loose, the resulting stress on the studs causes them to shear?

I think we all agree that the OP had a lucky escape, and the resulting discussion will at the very least, ensure we all take some extra time when mounting wheels to our trusty steeds.


regards

Dave
 
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130nm must be for steel wheels 'cos it's 103nm (76lb/ft) for alloys which can be exceeded relatively easily even with the standard brace. When I eventually started using a torque wrench after shearing 2 studs I reckon I must've been torquing the alloys up to well over over 100lb/ft in times past. They are certainly much easier to remove now they're correctly torqued up! I use anti seize compound on the studs (copper slip) not bearing grease, there is a difference.
130 Nm is for alloys on the 100, with 14 mm studs, as opposed to the 12 mm of the 60, 80, 90, etc series.
 
I've been using one of these wire wheels in a drill a lot lately and have found it works really well at cleaning threads up.

It would only take about 30 seconds to do all 6 studs with a cordless drill, well worth doing if your changing your wheels and the threads are rusty. :ugeek:

wire wheel.jpg
 
Well I have to stand corrected if the manual says don't grease but I'm going to ignore that. My audi manual said not to grease and during normal running with clean threads the studs rusted into the threaded hubs so I turned to grease from then on. I do however tighten the nuts with the wheel off the ground as much as possible so that there is no possibility of the wheel trying to centre itself on the hub whilst fighting the weight of the car.
 
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