Valve Adjustments

[Lewis]

Interesting aside- this set up is called bucket tappets and they were designed by FIAT in the 1960's. My first 1970s era VW rabbit had them. It required 2 specialized tools to adjust the tappets- a depressor to get at the discs and a removal and insert tool to get the discs out and reinsert new ones with the proper clearances. The big problem is the expensive set of discs with a variety of thicknesses you need to be able to do the work in a garage. I used to take two days to do it on my VW- one day to measure the clearances and remove the discs with bad clearances- and the next day to trudge down to the dealer to buy the individual discs (the VW dealers parts department always had every size disc in those days)i n the sizes needed to get the clearances corrected. Then they had to be reinserted. There never was any need to remove the overhead camshaft on the FIATS and VWs to do this service and I doubt there is now for our Toyotas - unless you lack the correct tools.

Come to think of it there was a third and fourth tool you needed to do it right- a micrometer- to measure the discs thickness of the removed disc because the embossed # would almost always be rubbed off by the camlobes and of cause a set of feeler gauges to test the clearances.

My guess is the this set up really doesn't require maintenance nowadays- it is a much more stable setup than the screw down adjusters from the old days (reflected in the fact that the proceedure went from every 3K miles to every 20K miles even then) and with modern metallurgy the parts just don't wear out like they used to. Also what wear does happen is often offset by carbon deposits on the valves which tend to close off the distances as the wear increases the distances thus pretty much ending up a wash.

I frankly doubt that many dealers even invest in the giant trays of discs needed to actually do this job- but knowing modern dealers they'd be most pleased to charge you for the service they literally can't even perform.

Only old guys like me (62) would know all this junk!

:-)