Drivers changing a trailer wheel on their own is fraught with all sorts of dangers, if they’re not sure what they’re doing
Many truck drivers are expected to change a trailer wheel, but many don’t know how.
This has obvious health and safety as well as chain of responsibility (COR) implications if things go wrong.
Yet there is very little formal advice out there for drivers on how to change wheels properly and safely, or for managers on what to bring to their driver’s attention.
One of the few sources is the Australian Trucking Association’s (ATA) Advisory Procedure Commercial Vehicle Wheel Security, available on the internet.
The advisory doesn’t have photos though, so ATN thought we would try to complement it with some of our own.
Tips for using a truck jack
Following are some of the key pointers from the ATA’s advisory on wheel security and vehicle jacking:
- Position vehicle in a clear area, safe from traffic and on a level surface suitable for jacking
- When changing wheels on road verges, always use safety warning equipment
- Apply park brake
- Ensure the vehicle is adequately secured by use of chocks
- Position jack under vehicle in a suitable location (refer to vehicle manufacturers recommendations on jack placement)
- Raise jack until wheel is clear to remove. The use of axle stands is recommended
- It is advisable to deflate the tyre to be serviced before removal
- In a dual situation, the second tyre should be inspected for signs of damage, and deflated before removal if damaged
Disc Wheels
Most new trailer wheels these days are discs, be they 5, 6, 8 or 10-stud.
Removing Disc Wheels
The vast majority of 10-stud disc wheels worked on by Southern Tyre Service are ‘hub-piloted’ discs. Basically these have one set of nuts on the outside.
The ATA has the following advice for removing these types of wheels:
- Remove all wheel nuts taking care not to damage the thread on the studs
- Remove the wheel from the vehicle avoiding contact between the wheel and the studs
- Apply correct manual handling techniques
- If a wheel has become stuck onto a hub assembly, use a rubber mallet and strike the inner rim flange to assist in removal
Replacing Disc Wheels
This next section of advice relies on the advisory’s recommended tensioning sequences, which it illustrates for the different type of discs. Basically it involves starting at the top and going diagonally opposite for the next nut.
Because drivers aren’t going to have an accurate torque wrench though, it gets really tricky judging just how tightly to do up the nuts. The ATA advisory has an appendix on how much lever length is needed for different manufacturer’s recommendations.
- Ensure all hub/drum mounting faces are clean and allow a flush fit with the mounting surface of the wheel
- Ensure that the wheel mounting surfaces are clean
- Clean all studs and threads
- Lightly lubricate between the nut and flange, and on the outer end of the stud threads
- Mount the wheel on the hub using correct manual handling techniques
- Ensure a flush fit between the mounting faces of the hub/drum and wheel
- Take care not to damage threads while mounting the wheel
- Install flange nuts finger tight at the 12 o’clock and then at the 6 o’clock positions. The remaining nuts may then also be fitted finger tight
- Using the correct tightening sequence, apply an adequate amount of tension to the wheel nuts to effectively seat the wheel onto the hub
- Using adequate wheel brace length recommendations tighten the wheel nuts to recommended manufacturer specifications, using the correct tightening sequence
The driver then needs to check the nuts with a wheel brace 50km to 100km on.
Spider Wheels
As the ATA advisory cautions, with these older style of wheels there is potential for “serious injury” from dislodging the rim clamps, which are also called wedges or dogs.
In fact drivers have been killed from wedges firing off like hand grenades.
Removing spider wheels
- Loosen the hex nuts until they are no longer in contact with the rim clamps (wedges)
- Ensure that the hex nuts remain fully on the threads of the studs
- Tap the wedges with a hammer until loose. (Caution: Stand to side of assembly out of possible trajectory of wedges)
- Wheel nuts can now be fully removed once wedges are dislodged.
- Remove the outer wheel using correct manual handling techniques.
- Remove the spacer band from the cast spoke using a side to side pulling motion.
- Remove the inner wheel using correct manual handling techniques
Replacing Spider Wheels
The ATA advisory continues:
- Ensure all rim clamps wedges and cast spoke mounting surfaces are clean and allow a flush fit with the mounting surface of the wheel
- Ensure wheel mounting surfaces and spacer bands are clean
- Clean all stud and threads
- For dual assemblies, mount the inner wheel on the cast spokes, positioning the location indicators between the spokes, using correct manual handling techniques
- Take care not to damage threads while mounting the wheel
- Then place the spacer band over the cast spoke using an even pressure on both sides
- The spacer should sit against the inner rim and fit snugly over the cast spokes
- Mount the outer wheel on the cast spokes, positioning the location indicators between the spokes, using correct manual handling techniques
- Take care not to damage threads while mounting the wheel
- Secure the wedges into position
- Using the correct tightening sequence, apply an adequate amount of tension to the hex wheel nuts to effectively seat the wheel onto the cast spoke mounting surfaces. This must be done in a gradual and even manner to ensure that the wheels and spacer band remain properly aligned on the cast spokes
- Using adequate wheel brace length recommendations, tighten the wheel nuts to recommended manufacturer specifications using the correct tightening sequence.
Spider nuts generally don’t have to be tightened as much as discs, but they still have to be checked 50km to 100km down the road.
The ATA advisory doesn’t mention it, but most old-timers will tell you to spin a spider wheel beside something straight to check that it’s running true and won’t wobble its way down the road — which can cause all sorts of problems.
The catch is that the brakes to this wheel need to be off to be able to spin it, so you have to be really sure the chocks are going to hold, preferably on flat ground.
Ideally you would have someone else sitting in the driver’s seat ready to whack the brakes back on if need be.
Final Thoughts
Cheney is a sales rep with Southern Tyre Service, and has been in tyres for more than 20 years, much of that time as a tyre-fitter.
He has a handy piece of advice for tightening spider nuts: tap the wedges after you’ve already done the nuts up as tight as they will go, and you’ll find you get an extra bit of turn.
He advises against jumping up and down on a bar to loosen tight disc nuts, having seen a bloke smash his chin on the side of a trailer after slipping off a bar.