Bearing up
It was service time on the Discovery V8 once again and a check of the front wheel bearings revealed a lit tle too much play in the front left and needed to be remedied. Wheel bearings are one those things we tend to ignore until the wheel collapses or we jack up the vehicle to physically check them as they do at WoF time. At the time I had just returned from a weekend outing where the vehicle had been subjected to some deep wading and water holes which is one sure way to contaminate wheel bearings. Wheel bearings generate heat and wading into deep cold rivers and streams gives that sudden cooling aspect of the hubs and creates a vacuum behind the hub seal and can suck water into the hubs and bearings. Another factor to impact on the wear of wheel bearings are the large tyres we fit to vehicles, especially when we use increased offset rims to accommodate these tyres which increases the side loading on the wheel bearings.
Handy hint #1
Overtightening or loose ( under tightening) wheel bearings will lead to the ultimate failure of the bearings so it is important to know how to set them up correctly. Rather than knock at the bearing nuts with a hammer and chisel or screwdriver, invest in the proper sized tube socket for your vehicle. For Land Rover the nut is 52mm which is the same size as the hot water cylinder element, and sockets for these are readily available in the plumbing department at your local hardware store such as Bunnings, Mitre 10, etc. On removing the hub, I had indeed had water contamination inside the hub so it was going to need closer inspection of the bearings rather than a simple adjustment – so the brake caliper had to be removed and tied up out of the way. The lock washers are then undone to allow the first of the nuts to be removed, followed by the lock tab and second nut. Once the hub was removed the other bearing was showing signs of corrosion so it wasn’t just from this latest dunking, and new bearings and hub seals were going to be required. The stub axle was showing the first signs of wear but time spent ‘polishing’ it with very fine wet and dry sandpaper had it suitable for continued service. When it comes to replacement bearings the advice is don’t buy cheap, ever! If you have to save money, do so by fitting a cheaper sound system, as wheel bearings play an important role by ensuring your wheel doesn’t fall off; sort of important if you think about it! With cheap bearings, any bearing in fact, it’s all about the metallurgy and the manufacturing process and materials used to make the bearing, and cheap bearings do not last. It is best to buy good quality Japanese or European bearings such as Timken, SKF, etc. I fortunately had a SKF bearing kit in stock which comes complete with new hub seal ( genuine Land Rover in this case), drive flange gasket and new locking tab. The hub was thoroughly cleaned and the bearing shells knocked out and the new ones fitted. It is extremely important to properly pack grease into the bearing and if you don’t have access to a packing tool it is best done by putting grease into the palm of your hand ( preferably with gloves on) and pushing the bearing into the grease, forcing the grease into the bearing. Work around the bearing and keep adding grease until it is coming out the other side.
Handy hint #2
Fitting the hub back onto the vehicle it is important to get the bearing tightened correctly. A tip I was taught was to temporarily fit the wheel back on and spin the wheel giving it a couple of ‘ thumps’ to settle the bearings into place. This is best done with a steel rim or at least one that you can torque up the nut with your tube spanner through the centre of the rim. Once done, fit the lock tab and second locking nut or a replacement stake nut if you have a later type vehicle hub and don’t forget to fold over the locking tab. All I need to do now is check the other side as chances are that it too will be contaminated, even though at this stage there is no excessive wear or play in the wheel.