Check your wheel nuts

[renewablejohn]

Just had my rear twin wheels collapse on my Merc 814. Made the mistake that because the wheel nut indicators were not unscrewing then the wheel must still be secure. The studs have produced slots in the wheels which eventually have worn through 75% of the studs until they snapped. Fortunately I was on a minor road when it happened if it had been a day earlier on the motorway I dread to think what would have happened. The wheels were only fitted by a professional tyre company 3 months earlier so I am shocked about the amount of wear.

[treequip]

This just goes to show the value of a walk round inspection which should be done at the start of each shift. It should also have been picked up by your scheduled safety inspection which ought to be every 6 weeks or so. Speak to whoever does them and ask why it wasn’t, I would also be asking them for a contribution to recovery and repair costs.

 

Any wheel fastener should be checked after fitting, most tyre companies put a big caveat on the paperwork and or a sticker in the cab.

 

For the kind of wear you are talking about I would have expected to see rust trails on the wheels which are a dead giveaway.

[renewablejohn]

Treequip

 

Wheels are inspected at the start of each day because Merc 814 are notorious for losing their front wheels due to the silly split washers which they use. The outer wheel showed no sign of movement and the 'z' band connecting each pair of nuts had not moved. When I recovered the outer wheel 2 of the 3 'Z' bands where with the wheel and the nuts and studs still firmly attached in the 'Z' band.

 

Garage had only inspected the truck on Monday and picked up a gear linkage that will soon need replacing.

[treequip]

Can’t understand how they missed the fact that a wheel was about to fall off

[PeteB]

I would have "felt" that something was wrong if I was the driver. A slight waywardness in driving should have been apparent if they were that bad surely.

[Highland Forestry]

could somebody have tampered with them after checks etc??

[renewablejohn]

I would have "felt" that something was wrong if I was the driver. A slight waywardness in driving should have been apparent if they were that bad surely.

 

Front wheels yes you can feel it through the steering but rear wheels are different especially twin wheels. I once had the inner tyre wall collapse but only noticed it while filling up at a petrol station. Even knowing it had collapsed you could not tell any difference in the truck cab.

[liamjordan]

a mate of mine had some of his nicked and some slackened by some ****** from down the road... could have ended badly

[TRADITIONAL LOGGERS]

I checked with Mertrux and the Mercedes "Operating Instructions" Part Nr. 673 584 10 96 Order Nr. 6550 6487 02

 

Wheel Nuts:-

 

709-914 = 250 NM Torque

1114-1524 = 300 NM Torque

All wheel drive versions = 300 NM Torque

 

As the threads are right handed then the kerbside is a possible issue on these wheel nuts if people are not careful. After changing wheels ALWAYS check after doing 50km/31miles!

 

New/Repainted wheels need to also be checked again after 1000-5000kms/620-3100 miles.

 

Do check the spare at the same time. Pressure/Tightness.

 

I would also check the bearing and seal if you had a problem with the wheels. I have a MB914 AK-31 and it is a nice reliable work vehicle.

Edited January 21, 2011 by TRADITIONAL LOGGERS
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[robbo 110]

Treequip

 

Wheels are inspected at the start of each day because Merc 814 are notorious for losing their front wheels due to the silly split washers which they use. The outer wheel showed no sign of movement and the 'z' band connecting each pair of nuts had not moved. When I recovered the outer wheel 2 of the 3 'Z' bands where with the wheel and the nuts and studs still firmly attached in the 'Z' band.

 

Garage had only inspected the truck on Monday and picked up a gear linkage that will soon need replacing.

 

you are right, 814 & atego both suffer with this, the split washer is a spring washer & needs replacing as soon as it has no spring left!!!! the wheels also need to fit reasonably tightly on the hub, (hubcentric fit) the hub will of worn over the years, ive built up the hubs using a mig welder, make sure your not using worn rims when this repair is carried out though!! with regards to this not being noticed an an r&m inspection, the inner wheel, if worn will move slightly whilst the outer wheel appears tight, over time it gets worse, unlikely a driver will notice this until its to late, vosa find these easy pickings as the split washer doesnt close completly if they are rusted slightly, PG9 for insecure wheel nuts evan thou they may well be torqued up correctly,

 

the spring washers for the wheels are very cheap, replace any worn studs an check the wheel nuts, they do wear out!! hope you get it all sorted

Edited January 21, 2011 by robbo 110