An old Bosch cast iron distributor is not indestructable, but we want it to be. I think Bosch initially felt the same way and that's why the Bosch distributor rebuild kit PN 1 237 010 007-000 was made available as a spare parts item. Knowing this part number is sort of the secret handshake that really gives you an opportunity to buy a cool little collection of parts to rejuvinate most of the VW distributors Bosch issued over the years, including the lesser aluminum bodied units. Yeah--I said lesser.
The parts in this kit will rebuild more than just a VW distributor. Maybe you have an old Volvo distributor to rebuild? This will be the kit for you, too. And each of these kits can potentially rebuild more than just one distributor, depending on model and condition of shims. Some of the old versions of this kit include a few more parts than those shown, too.
The 'Holy Grail' of Type 3/34 distributors is the much lauded Bosch ZV/JCU4R3. If you have a nice one on your car, you'll know what I mean. I've even considered putting one of these on my wife's Type 14 (see previous post) to replace the Bosch '010'. These distributors were installed only on the '64 1500S dome top pistoned engines. The engine room in the Nautilus will eventually be appropriately equipped and I do plan to detail the build-out of that power plant in future posts.
If you're in the market, Glenn Ring rebuilds and sells these on occaision, along with many other distributor types. Check here for his stock on hand.
I currently have three ZV/JCU4R3 distributors and may one day restore and sell one of them. As much as I try to not horde parts, keeping a selection of readily available spare parts has bailed me out of so many bad situations that I no longer feel overly guilty about it. An extra distributor is not too out of line--but two spares could be stretching things a bit. Keep checking the 'Parts Bin' for the current stuff I have for sale, as I'm starting to come to some conclusions about which parts will actually be used on my own restoration. The rest will have to go, as my long suffering wife wants to use the basement for something other than auto parts storage.