Torqueing Nuts - The Trade Side

The issue of the correct torque settings for wheel nuts raises its head from time to time. One popular motoring magazine suggested that a majority of tyre depots did not correctly torque wheel nuts and that this created, at best, a nuisance for drivers, at worst a safety issue.

To be fair torque setting is not just an issue for the tyre trade: it is an issue throughout the motor trade and is exacerbated by the increasing use of air wrenches for every nut and bolt task. The issue is less one of training, but rather one of monitoring. Companies may train their staff all they wish, but at the end of the training many staff go back to their depots and carry on doing it the same old way. We have all been sitting in on training sessions and said, or heard said, "That's all very well in theory, but in practice..."

Question?

How can the tyre trade improve its performance in this field, monitoring the effectiveness of the training, and ensuring that the lessons taught in the classroom are followed up in reality? That applies equally to jacking up cars, repairs, fitting, balancing as well as torque setting the wheel nuts.

It is worth noting that in the caravan sector many of the specialist service centres will mount wheels on the caravan and manually tighten the wheel nuts, but will not release the caravan to its owner until he/she has personally tightened the wheel nuts. Thus relieving the service centre of liability should the wheels then fall off!

Is there a need for industry backed performance monitoring?

Mystery shoppers are all well and good, but if the customer doesn't know that the quality of the work being done is inadequate, how can he tell? How can the mystery shopper tell? If a nut is over-torqued by the air wrench in the first place, checking with a torque wrench afterwards will only give a minimum reading. The wheel nut could be 10-15-20 Nm over tight, checking with a torque wrench will not readily show that.

Dave Smith, Chief Training Officer at Michelin's Stoke Training Centre agreed that it was his job to train to the highest standards in the classroom, but out in the field it becomes an operational management issue. Asked how checks could be run at depots he suggested that following the policy of one particular chain the fitter who mounted the wheels would set the torque and fit the wheels but the job had to be signed off by a senior technician or depot manager.

James Bailey handled our enquiry at Hi-Q and he agreed that monitoring was difficult but added, " Hi-Q has a national policy of checking torque settings but always recommend that the motorist checks the wheel nut torque setting after a few hundred miles."

On the truck-side Hi-Q use a Torque Right gauge to ensure that wheel nuts are tightened to the correct setting. It is something that could be looked at for the car market too.

ATS Euromaster, as one might expect, train staff to the highest standards, but once again when the staff leave the classroom how do the standards get monitored?

At the depots wheel nuts are run-on with an air wrench and the torque settings, taken from a wall chart guide, are set by torque wrench. It is policy at ATS Euromaster that the senior technician at the depot should check the torque setting of the wheel nuts on every vehicle before it leaves the depot.

However, in reality it may well be that this ideal is not always attained. There is though a further check in place. There are quarterly competency checks run by the depot managers on all staff in all areas of skill application. For truck fitters there is a specialist five day training course designed to ensure that they are fully competent in mounting tyres and wheels to commercial vehicles under all conditions.

National told Tyres Online, "National Tyres and Autocare has strict procedures in place to ensure that any work carried out, including tyre fitting, is performed to the highest standard. Any branches or individuals identified as not following these procedures could face disciplinary proceedings."

All the fast fit people we spoke to were adamant that they were doing their best to check settings. However, the one question that no-one could adequately answer was, if the settings are too tight, how can the supervisor be aware of this? Also, if the nuts have already been over-torqued by as much as 50 per cent the threads will already have been damaged and the studs stretched. Will the retailer then replace the studs and nuts free of charge? Will they offer redress for potential damage to alloy wheels?

In any event, how does the client know what the correct torque setting for the wheel nut should be? It isn't in any owner's Hand Book Tyres Online has seen. One suggestion is that the torque setting for the wheel nuts should be displayed on a sticker on the door pillar alongside the tyre pressures guide. Then again, would that not just be another piece of information for the motorist or the mechanic to ignore?

There is no denying that this is a tricky question. It is also a wider subject than just wheel nuts. If the tyre trade can find a workable monitoring system to ensure that the correct standards are being met then it may well be taking a lead for other automotive servicing sectors to follow.