TR6 Engine rebuild

[joe90]

Yes me again, still trying to get my 1970 TR6P back together!  This engine has the breather on the rear of the primary chaincase and I am told that the engine breathes through the crankshaft main bearing and hence you do not fit the oil seal behind the crankshaft sprocket, oil returns through 3 small drillings in the side of the crankcase, is this correct?  Presumably therefore the chaincase should contain similar oil to the engine as it will mix, what is the best oil grade to use?

[L.A.B.]

This engine has the breather on the rear of the primary chaincase and I am told that the engine breathes through the crankshaft main bearing and hence you do not fit the oil seal behind the crankshaft sprocket, oil returns through 3 small drillings in the side of the crankcase, is this correct?

Yes that should be correct for a 1970-on model. (although some early ones may have kept the seal and breathed through larger drain holes?).

Presumably therefore the chaincase should contain similar oil to the engine as it will mix, what is the best oil grade to use?

Any good quality 20W/50 multigrade oil.

[joe90]

The 3 crankcase holes are tiny so I think I will leave out the oil seal.  Thanks again for a timely reply as I intend to start rebuilding the clutch and primary drive tomorrow morning 8.00am sharp!

[TBS]

I only use Silkolene Chatsworth 40 which is a straight oil, which is perfect for Triumph roller bearings etc. Never had a problem, but as L.A.B says a good, and I mean a really good 20/50 oil, (never synthetic) is fine.

[joe90]

Thanks for the oil information, I have another question!  Is it advisable to use gasket cement on the cylinder base gasket, just use grease, or nothing?  The Haynes manual says "no gasket cement".  After going to all this trouble I am hoping for something reatively oil tight.

[TBS]

I always use Wellseal jointing compound on the base gasket and gearbox sprocket cover plate gasket, but nothing on any other gaskets.

[joe90]

Thanks, just off to do it now!