First published in the January 2003 issue of Street Machine

Grease it right

Wheel bearings usually go about their job with little or no fuss, but like all moving mechanical parts, they don’t last forever. A good rule of thumb is to replace them every 100,000 kays – 70,000 if you’re running wide tyres.

Additionally most mechanics recommend changing wheel bearings if the old ones need to be swapped over when installing new brake rotors.

Bearing installation is a fairly straightforward operation – any good workshop manual will show you how. However, there is one area that can bring you unstuck and that’s correctly packing the new wheel bearing with grease. Grease on the outside of a wheel bearing does very little, it’s the grease on the inside that matters most. That’s why it’s called packing, rather than greasing, as you need to completely fill the interior of the bearing.

Starting with clean hands and clean high-temperature bearing grease, put a generous dollop in the middle of your palm, then working on a small section of the bearing at a time, push the edge of the bearing down into the edge of the grease dollop. This forces the grease up into the bearing.

Nibble away at the dollop bit by bit. You’ll know when the section you’re working on is full as the grease will squeegee out of the top. Once one section is finished, rotate the bearing and start working the grease into the next section. Don’t cheat, keep working the grease up into the interior of the bearing until you physically see grease squeegeeing out of each section of the entire circumference.

Note: Never wash and repack old bearings, as it’s impossible to stop some of that nasty grunge on the outside ending up on the inside of the bearing where it will quickly wreak havoc.

Bush survival

Ever spent a weekend replacing all those old, flogged-out suspension bushes in your streeter with high-quality units, only to find that after a minimal amount of kays they’re not much better than the 20-year-old units you just yanked out? According to the various suspension bush manufacturers, this is a common customer complaint. However, the problem can be a simple matter of not properly reading the instructions.

Like the factory originals, the centre sleeve in most replacement suspension bushes is not designed to rotate within the bush. Rather the outer casting and centre sleeve are bonded together via a rubber/urethane membrane. It’s the flexibility of this membrane that allows the suspension to move up and down.

So if you jack up the car and tighten up the bolts with the suspension sagging at full droop, the bushes will twist to nearly the full limit of flexibility when you drop the car off the jack and the suspension moves back up to static ride height. A few miles down the road, when the suspension tries move up over a bump, there’s no give left in the bushes and they start tearing themselves in half.

Try liberally greasing the face of the bushes (rubber grease is usually supplied) then wait until the car is sitting back on the ground before finally tightening the suspension mounting bolts. This way the bushes are not pre-stressed or deformed at static ride height and have plenty of give in them to allow the suspension to move through its full range of travel without tearing those spanky new bushes to pieces.