Tachometer Drive Housing Gasket(s)?

[gfeher]

I've searched the forum quite a while for a direct answer to this question. I'm pretty sure I know the answer using common sense, but I'll ask it anyway given I haven't seen a direct answer. You just never know.

I'm aware that the generator/alternator shares it's gasket (p/n 36100, now 652072, also Superior p/n SA36001) with the tach drive housing. It's shown as item 9 in Fig. 18 (p. 32) of the C-145/O-300 IPC (Continental doc X30014), with the upper triangular portion for the tach drive housing.

But in Fig. 10 (pp. 18-19) of the same IPC for the engine, it shows another gasket (Item 32, p/n 641538 - still available/not superseded) for the tach drive housing. I assume that's a mistake in the IPC, and that only the joint gasket in Fig. 18 should be used. Would someone knowledgeable about this issue mind confirming whether or not this is a mistake in the IPC?

[gfeher]

Never mind. I now see what's going on. Fig 10 of the IPC shows the "new style" crankcase cover assembly (accessory case cover). Figute 8 on the previous two pages shows the crankcase assembly cover with the same gasket (p/n 36100) for the tach drive housing as for the generator in Fig 18. So there's no inconsistancy, at least between Figs. 9 and 18. That's the trouble with looking at these documents electronically. I didn't page back far enough to get the real picture.
Sorry for the confusion.

[Kurt Aichele]

If you are replacing the gasket for the alternator/generator and tach housing, you may want to consider replacing the oil seal for the tach drive, since you will have it off already.

[gfeher]

Thanks Kurt. That's what prompted my question. I was putting a list together of the replacement parts I might need (including for replacing the tach and alt/gen oil seals while at it), when I saw those different gaskets in the engine IPC.

[GAHorn]

Anytime that gen/tach drive gasket is replaced the tach drive oil seal PN 642714 should also be replaced. IMO