Just after buying the 4runner I had to replace the two front tyres, they were bald on the outside. Now if you have just bought a car and it has prematurely worn the front tyres don't just replace them, find out what caused it and fix the problem so it doesn't happen again!
I jacked the front up and started grabbing and wobbling all the ball joints. The only one that moved was the chassis-end of the steering idler arm. It wobbled a lot.
My local Repco auto shop couldn't do me a new one, but they did a "bush kit". Nah I thought with 3-5mm of wobble no bush is going to sort that out.
After a quick call to Toyota and pricing a complete replacement at AUD$180 I decided I'd take a punt with the $10 bush kit from Repco. I could roughly see where the bushes went and once I'd worked out that the tin hat on the top of the mount (removed in the photo) popped off revealing a nut it was all over. Undo the three bolts holding the arm onto the chassis, undo the nut on top and the whole assembly comes apart.
Sadly the shaft through the guts of the arm was badly pitted - obviously water gets trapped in and does it's damage. I took to the shaft with emery cloth and smoothed it up, but it is pretty far gone. None the less I put the new bushes in and bunged it back together and it didn't wobble anymore - we'll see how we go.
+2 years: The bush is still nice and tight. A recommended job.
+7 years: The bush end is a little bit wobbly, but the ball joint end is stuffed. That end cannot be fixed with a bush, so I had to get a replacement unit. Fortunately you can get aftermarket ones, this one set me back about $AUD100.