While changing valve cover gaskets and re-sealing the intake manifold mounts I decided on cleaning the throttle valve assemblies as well. Disassembly is pretty straight forward. Clean everything meticulously and you’ll be fine. I blasted the housings while I was at it, to remove the old yellow varnish. Some seals and o-rings might make it seem impossible the separate housing but they’ll give in eventually.
The only thing you need to be extra careful about are the fingers for the potentiometers inside, these are very easily damaged.
Before disassembly, untouched.
Before disassembly, but cleaned.
In the upper left corner you can see an anti-tampering screw, use a pair of pliers to remove it.
The one on the left has been cleaned with a scotch-brite pad.
You can use a pick to move the brushes back; they’ll stay in place with the help of the same springs that keep pressure on them.
Re-assembled and ready for install!