Ifor Williams loose wheels

[renewablejohn]

Was it the N/S rearmost wheel?

 

As this is the one that cuts in the most, drops in drainage gullies more on turns & hits/glances kerbs.

 

Lose wheel nuts can cause the above, typically if that is the case then the hub will show signs of wheel movement I.e. ware the hub/wheel meat will be shiny ware the parts have rubbed for a wile pre failure, ware the studs have just suddenly failed when the nuts have been tight you don’t tend to get prominent rub marks ware the wheel meats the hub so it stays rusty.

 

Also 7.5t trucks etc can put more turning force into a trailer than e.g. a land rover or transit van type ilk which puts more strain on the studs/wheel bearings etc over time.

 

It was the offside rearmost wheel. Hub shows no sign of wear to suggest loose wheelnuts. The trailer had already travelled from Bolton to Carlisle in the morning and this happened on the way back.

[techdavey]

I have an Ifor Williams twin axle plant trailer which threw a wheel off at 50mph on the motorway. Very disturbing but on close inspection all 4 wheel studs have sheared off. Is this common and if so should I replace the other wheel studs as they will all be the same age. The trailer at the time was carrying a Subaru Legacy so in real terms was well within the carrying capacity of the trailer.

 

New nuts and studs should be a good investment.

As to wheel loss it is more common than you'd think. As to why it happens look up Bolt Science. Basically there are two ways of fixing wheels to hubs. "Lugcentric" is where the weight is carried by the nuts and studs and "Hubcentric" where the wheel locates accurately on a centre spigot. Major car manufacturers now use Hubcentric as it is more secure. One disadvantage is that rusting can make the wheel exceedingly difficult to remove. As to the broken studs, overtightening is probably the culprit. Wheel nuts should be tightened manually preferably with a torque wrench, NOT hammered up as tight as the air wrench will go. As to the offside wheel coming off this is very unusual as precession (the reason why cycle pedals have opposite threads) will try to tighten the nuts on the right. On the left hand side precession tends to loosen the nuts. Trailers that use 3/8" UNF wheel studs can be rather problematic on the left hand side as when loaded to the limit the nuts can loosen. Threadlock will prevent this. Another way, if the studs are long enough, is the use of a locknut. I have in the past found broken HGV studs at the side of the road. Such studs are about an inch thick. Perhaps these components should be regarded as having a "lifespan" in a similar way to aircraft parts. Of course the problem could still be the slap-happy air-wrench-monkeys or potholes. At major car factories wheel nuts are robot tightened by computer. The computerised nut wrench actually plots a Hookes Law graph in its memory so to speak and the nuts are usually tightened up to the yield point. Not so easy to do in the field unfortunately but as the wheels are hubcentric they never fall off. Perhaps lugcentric needs to be relegated to the history books.

[Breezeblock]

New nuts and studs should be a good investment.

As to wheel loss it is more common than you'd think. As to why it happens look up Bolt Science. Basically there are two ways of fixing wheels to hubs. "Lugcentric" is where the weight is carried by the nuts and studs and "Hubcentric" where the wheel locates accurately on a centre spigot. Major car manufacturers now use Hubcentric as it is more secure. One disadvantage is that rusting can make the wheel exceedingly difficult to remove. As to the broken studs, overtightening is probably the culprit. Wheel nuts should be tightened manually preferably with a torque wrench, NOT hammered up as tight as the air wrench will go. As to the offside wheel coming off this is very unusual as precession (the reason why cycle pedals have opposite threads) will try to tighten the nuts on the right. On the left hand side precession tends to loosen the nuts. Trailers that use 3/8" UNF wheel studs can be rather problematic on the left hand side as when loaded to the limit the nuts can loosen. Threadlock will prevent this. Another way, if the studs are long enough, is the use of a locknut. I have in the past found broken HGV studs at the side of the road. Such studs are about an inch thick. Perhaps these components should be regarded as having a "lifespan" in a similar way to aircraft parts. Of course the problem could still be the slap-happy air-wrench-monkeys or potholes. At major car factories wheel nuts are robot tightened by computer. The computerised nut wrench actually plots a Hookes Law graph in its memory so to speak and the nuts are usually tightened up to the yield point. Not so easy to do in the field unfortunately but as the wheels are hubcentric they never fall off. Perhaps lugcentric needs to be relegated to the history books.

 

translated this means the set up has a poor design the wheel should not have a big gap on the spigot it should be a snug fit:thumbup:

[Treegeek]

Mate of mine had the same thing whilst he had his 20k winch challenge landy on the trailer going down the motorway he's verry good at his maintance and took the local dealer to task over the faulty thay where shocking ended up in a shouting match funny.

In all seriousness there seems to be an issue with these trailers and the i shudder to think that there could be incidents out there where the out come was not so good carrying landys plant all big bits of kit scary to think:confused1:

[robbo 110]

i was called to a 7.5 tonne truck today, noise coming from back axle, maybe had the driver done his daily check he may of noticed loose wheel nuts???? threadlock is in no way a neccesary means of keeping wheels on a vehicle, if you think that threadlock is the forwards i would ask you to change an o/s wheel whilst on the hard shoulder of any motorway!! both hubcentric & lugcentric systems will work if maintained properly, dirt/rust is the biggest factor wheels falling off, mercedes trucks have used both systems together, but they still come loose if they not fitted correctly,, takes minutes to carry out a walk around check first thing in the morning, regardless of whether its series 3 landy or an 8 wheeler,, far easier than watching your own wheel causing a fatal accident?

[Gareth Dalzell]

Always a problem when haven't had control of what's been on the trailer all its life. Other companies/people often don't have a clue what things weigh and often overload. Best ever I saw was a piece of quarry plant being towed by a guy I know who'd been told it only weighed 2.5t when he got to the quarry weighbridge it came in at 4.6t - thats a lot of stress.

 

Studs shear often when the nuts come loose, so that could have been a problem in a previous life for the trailer.

 

Definitely check/test/replace the other studs and worth getting the axle mounting brackets checked and the hitch system for wear - there are normally wear indicators on the hitches.

 

Worth giving the trailer a good check over - maybe even a quick service by an Ifor dealer as they've seen it all before and at least then you have a good paper trial if something goes wrong.