If you are doing a bearing inspection/regrease yourself, there are a few safety requirements that you need to cover off. You need a dry, clean and well-lit area with plenty of room around the van to work in. The ground must be firm and level.
If possible, hitch up the van to your tow vehicle (with the vehicle’s handbrake on and the transmission in Park or, for a manual, in first gear), because it’ll ensure your van won’t move while you’re working on it. The van’s park brake has to be in the released position, or you won’t be able to take off the brake drums.
Now you can loosen off the van’s wheel nuts, but don’t take them off yet. If you haven’t hitched up your tow vehicle to the van, get something solid such as a block of wood or a brick and chock the wheel not being worked on.
It’s time now to lift the wheel you’re working on off the ground. To jack up the van, find a solid point under the van to lift it from. Either a chassis rail or underneath the leaf spring are usually the best spot. Then support the chassis with an axle stand. Undo the wheel nuts and remove the wheel. Then you’ll see the brake drum, on the centre of which is the bearing dust cover.
Take the dust cover off by clamping it with a pair of pliers. You might find that the cover is difficult to remove: you can try tapping at it with a hammer but be aware that it’s made of soft metal so don’t take big swings at it.
You’ll now see the large castellated nut that holds the drum and bearings in place. The nut is locked in position with a split pin, which you need to remove with a pair of pliers. Grab the ‘leg’ of the split pin bent over the stub axle and straighten it, which should then allow you to pull out the split pin and then undo the castellated nut.
Now you’ll find a large washer loose on the stub axle, which you’ll need to remove before taking the drum off the stub axle. Make sure you have a cloth on the ground, as it’s likely that the bearing will be loose and may fall out of the drum assembly. The inner bearing seal (on the back of the drum centre) should remain secured on the drum.
Clean the stub axle with solvent and inspect it for scoring marks. It’s unlikely that it’ll be scored, but if so you or the previous owner has had some serious bearing problems. If the stub axle is scored, it must be replaced; it’s not a big job and new stub axles are not expensive.
Now take the brake drum and bearings to a clean work surface (you’ll find at this point that if you can work with the drum on a bench it’ll be much easier) and remove the inner bearing seal and inner bearing.
Thoroughly clean the bearings, castellated nut and outer washer and drum centre in a solvent such as kerosene or degreaser. Compressed air is best for removing the rest of the solvent from within the bearing, but using a clean dry cloth to remove the excess and leaving the bearing for a couple hours to dry out will do (making sure you give the bearings a final wipe-over after). Have a close look at the bearing rollers, and if you find a blue haze or discolouration or any pitting then bin the bearings, you’ll need some new ones.
It’s now time to put some clean grease through the bearings (using high-temperature grease – HTB). You can either buy a bearing grease-packing tool or simply force the HTB grease through by hand. That is, put some HTB grease on your palm and push the bearing down on the grease (see photo) until the grease has pushed out the other side of the bearing. Make sure that you do this all around the bearing.
Now you need to wipe out any old grease from the drum hub and make sure that the bearing cups are properly seated in the brake drum – either with a cup seating tool or using a hammer and tapping on a piece of timber shaped to sit in the bearing cup. Then apply a light smear of fresh HTB grease inside the drum hub.
Reassemble the bearings in the brake drum and tap in a new inner bearing seal. Then mount the drum on the stub axle and fit the washer.
Now comes the tricky bit. Proper bearing adjustment is vital – if you want your bearings to have a chance of lasting for 100,000km. Get it wrong and they’ll last for a much shorter distance.
Start off by re-fitting the castellated nut, easing off and retightening the nut a few times and also spin the drum to let grease work its way into bearings.
You need to tighten the nut enough so that the brake drum becomes difficult to spin. Then ease off tension on the castellated nut so that the drum can spin freely for a couple of rotations before slowly coming to a stop.
When you’re happy with wheel bearing tension, lock the castellated nut in place by fitting a new split pin. In the last few years AL-KO stub axles have been cross-drilled, doubling the pin entry points available, thus, reducing the chance of having less than optimal bearing tension. Ensure that the head of the pin is seated and bending one half of the ‘split’ section towards you, along the face of the stub axle. Cut this section of pin where it protrudes past the stub axle with pliers, and cut the other section where it protrudes from the stub axle. Put the dust cap back on by tapping it gently around the edges of the face with a hammer.
Put the wheel back on and tighten the wheel nuts, then drop the wheel down back onto the ground (by lifting the van off the axle stand with a jack and removing the axle stand before lowering the van again).
Now you can tighten the wheel nuts fully to around 130Nm of torque. The wheel nuts should be checked to see that they haven’t come loose after towing for around 100km.
With thanks to Complete RV Services, Unit 3, 85-87 Batt Street, Penrith, NSW 2750, 0423 384 873 for their assistance with this article.