Impact Bolting

[Odyssey02]

Today i visited Eng Wah tyres and batteries to install my new set of rims for my Odyssey. To my dismay, when Vincent the boss was loosening the bolt of my front right tyre, the long screw (the stick which we mount the rim on) broke off, leaving behind only half of it. He claims that it is because the usual tyre shop i patronise did not mount the tyre correctly thus when he unbolted the nut, the screw broke. The usual tyre shop i patronise which is next to Serene Centre at Farrer Road called Hurry Tyre tightens the bolt by hand whereas Eng Wah uses the powered type. Now, i have to spend money to bring the car back to Kah Motors to have the screw replaced. Can anyone tell me who is the one in the wrong?

[Silver_blade]

It is unlikely to be Eng Wah's fault. He was just loosening the bolt. The boss's claim could be right. The bolt will suffer alot of extra stress if the wheel is not mounted properly.

[Odyssey02]

now the complicating thing is that we have to bring the car back to KM. according to Eng Wah, the bearing (?) has to be taken off before the screw can be changed.

[Silver_blade]

I also think the bearing will have to be removed to get bolt out. No an easy job. Likely that wielding is needed fix a 'key' to the broken bolt in order to take it out.

[Megalord]

Unlikely its the lossening of the bolt @ fault, for only ample torque is needed to remove it. Tightening by hand, however, allows very very high torque to be applied, where a normal 1/2 inch T-bar can apply over 300NM of torque with an extension. As for the removal of the bolt, can be easy of difficult, depending on the type of mounting bolt it is used on ur vehicle. Some are locked on(like in the case for 3-tonners), some are screwed on in a way(this is more difficult, got to use the welding key method, or if less severe, the use of double or tripple nuts should suffice), and i think there are other methods...

[Odyssey02]

omg...my dad is going to grumble. as my dad did not want to spend a lot on the rims, the ones we got today were actually 2nd hand ones which the latest Odyssey owners traded in, thus we only paid $400 which was a real bargain as the steel wheels i was using cost $100 for the plastic cover to be replaced so since there was such a good bargain why not? but now, having need to spend money at KM again... Seriously, KM charges quite high for its parts as we were charged $100 for a new seat belt buckle as the sensor in it for the airbag was faulty.

[Silver_blade]

You might be able to go to a 3rd party workshop to have it removed. I wonder if Jeep Chee or Man Exhaust can do it, cos they have the wielding equipment.

[Roberttan]

but do remember tyreman is not the only person do the mounting of wheels

mechanic need to remove the wheel to inspect the brake too.

if you do not have any vibration problem I shall say the wheel are balanced and properly

mounted.

one thing for sure is power tools are tend to overtighten unless it was preset torque.

sometime is no point making wild guess like this it also could be due to wear and tear or

driving and road condition.

remember we heard about those light weight nuts?some accident happened due to those nuts when on hard driving.(that is ?police catch)

the only real good quality one is the forged type with reliable brand,those low grade are cast aluminium type which came with private label and make by who?(I also don't know)

so be safe don't always look for the cheap or cheapest.

[Odyssey02]

I changed my tyres right after the 40000km sevicing so i doubt it would be wear & tear and we did nothing to the wheels after the tyre change till now so shall see what KM says when we bring it back. Furthermore, the nuts were the original ones that came with the car.

Edited April 2, 2005 by Odyssey02

[Sky8807]

IMO tightening by hand would be unlikely to cause the stud to break.

Either the particuliar stud had been overstressed and overtorqued previously waiting for it to break or the shop tightened instead of loosen using the power tool.

 

Some tyre shop overtighten the nuts using excessive torque that are set for heavy vehicles like lorry. For these type of veh (lorry) normally hand tighten is insufficient.

 

I had an encounter a few months back when I purchased a 2nd hand car, when ask the dealer to change tyres, not only they give me lousy tyres but they tighten the wheel nuts even using power tools at the wheel alignment shop later cannot even remove the nuts. At the end, have to use a very long entension to remove one of the nut.

[Megalord]

Ermmm... Actually i have broken quite a few of those threads before... Most of the time by overtightening, and once by removing, this one jia lat--> 10 bolts 6 broke. All those that broke, less 1, are all from class4-5 lorries, and all by hand. Never have a prob with air-wrench tightening. You see, most air wrench even for big lorries, max their torque @ slightly above 600NM(some better ones close to 800NM), but... most don't even come close that rating, for their compressor can't be too big. By hand, however, its easy to achieve a rating of 300NM by simply pressing on a 3/4 inch T-bar(or sliding handle socket if need to be more precise), and by using legs, i can achieve something close to 600NM on this T-bar. Using extensions, i can achieve 1,200NM, tested before. Thats why we always tend to share a common concept, hand tightening is always very powerful, and more powerful than the power tools.

BTW, your thread may not be a stud type, do go check out first. Do take note of the lock on type i talked about.

Edited April 3, 2005 by Megalord

[Sky8807]

By hand, however, its easy to achieve a rating of 300NM by simply pressing on a 3/4 inch T-bar(or sliding handle socket if need to be more precise),

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Wow, u must be a strong guy to torque more than 200 ft lb by hand easily.

Guess for u half strengh is more than enough to tighten wheel nut.

 

It does not matter whether it is a stud type or lock on type, the main thing here is the tightening of the wheel nuts.

 

The best is using a torque wrench. This tyre shop at bukit timah 10 mile (opp ten mile junction) that I go to for tyre rotation and repair always uses torque wrench to tighten the wheel nuts.

[Odyssey02]

the person who broke the bolt claims the previous person who tightened the bolt fixed the wheel wrongly thus putting stress on the bolt so when he unbolted the it, it broke off...but no idea whos in the wrong as this is the first time i ever heard of such a thing plus i have been patronising Hurry Tyres since i got the car.

[Sky8807]

Well when things happen, everybody blame somebody.

Quite puzzle, on the fixed the wheel wrongly. Is the nuts fitted the wrong way in or what? any idea

If that the case, you nut is at the danger of breaking anytime when a load is acted on it.

Anyway, this item don't break that easily unless abuse by ppl.

Look like u have to note down the tyre shop workmanship, if they are the only one that touch your wheels.

[Megalord]

You don't need to be strong to acheve that. Do have a look @ how long a 3/4" sliding T-bars usually are(not seen usually), then you consider if you can efficiently apply part of your body weight(dun need to stand even, use your hands to apply body weight), how much torque you can apply. No use pushing too much using hands, an efficient mechanic works with the least force excerted->less tiring.

Nono, the stub or lock on type is for the thread starter, the removal method varies alot, not in discussion here, but technically speaking... stud types are... Nevermind, none of our concern here.

Yah, i got 5 torque wrenches to lend from(1/4, 3/8, 1/2, 3/4 and 1"), but anything from 110-300NM, i still can guage with a fair bit of accuracy. How? Simple, after torqueing everything i need, drive to that place, and re-torque. Then i will find out how close i am to the actual reading. Still fairly close though i quited as a mechanic for some time liao.

[Megalord]

I still think its the person who torqued your wheel @ fault. As it is now, i can lay a trap as in torque a nut on a bolt so much so that its close to breaking point. So far i can only achieve this on hardened threads like those on your wheel hub, those alunimum or softer ones tends to cross-thread instead. So the moment someone else come to it and apply anti-clockwise force not enough to lossen the bolt/but, due to statics and mechanics, the bolt will break. The best case is you tighten until a stress line forms. That one mostly break when released. You see, releasing, we only need to overcome the torque, and the excess amount of force is used in rotating your bolt or nut out faster. If he broke it when extracting it with a air-impact wrench, i can safely say i will have a 90% chance of breaking it if i were to remove it by hand.

[Megalord]

You see, even if the nuts(haven't seen, can only guess) are directional(protuding on 1 side) as in the case of land-rover types, 110NM is still 110NM. You can't break the thread simply by applying the same force on a reversed nut. I too agree that it can be dangerous, though the main aim of the nuts/bolts is... Nevermind, non-of our concern here as well.

[Genie47]

Ah! this highlights why proper amount of torque is needed even for wheel nuts/bolts.