Triumphrat

dorkingbonny · 10-28-2006

I have a 1970 T120R with the breather that exits at the rear top of the primary chaincase, and am confused about the conflicting advice from Haynes and the Owner's Handbook.

Is the oil level in the primary case kept topped up from the engine oil?

If so, when do I need to refill the primary - if ever?

What is the best oil to use? - same as the engine if it is kept topped up from the engine, presumably?

I intend to use it through our winter in UK (only on dry, frost-freee days) - can I still use SAE40 oil?

Thanks for any help

Mark

dorkingbonny · 10-28-2006

I forgot the other question - if I have to refill primary, do I use 350cc as Owner's Handbbok, or 150cc as Haynes specify for Year 1970 onwards?

Confused!

Thanks

Mark

peintremondain · 10-28-2006

150cc are enough!350 cc is a mistake!!!!
ben

OzBloke · 10-28-2006

DorkingBunny,

The primary uses the same oil as the engine. When you change the engine oil, dump the sump oil, and the primary chaincase oil as well. Lubricate the primary chaincase with 150mL of standard engine oil. When the engine is running, oil vapour is passed to the primary chaincase from the crankcase via the breather holes in the left hand crankcase. This vapour keeps the primary "topped up", and you should only need to add/replace oil in the primary chaincase when you dump it for maintenance.

Lot's of opinions on the forum about the best oil to use. Personally, I use Penzoil 20W50 for air cooled 4 stroke engines -red stuff - never had any issues with it. Up to you.

dorkingbonny · 10-29-2006

Thanks Guys

Just to clarify, when I empty the engine oil, this will not also drain the primary as well will it?

Thanks

Mark

quagmire · 10-29-2006

NO, the primary needs to be drained separately. You should have two bolts on the right side of the primary cover. The upper one is the oil level plug, the lower one is the drain/ primary chain tensioner plug.

dorkingbonny · 10-29-2006

Thanks Guys - changed engine, gearbox and primary drive - beautiful!

One other thinG

Can I use SAE 40 "straight" throughout a "winter" - in the south part of UK?

Mark

DAGAD · 10-30-2006

Hi mark, NO don't use a straight 40 for winter, use a 20/50 mineral oil and a Straight grade sae 20 for the primary oil. No time to give explanations now, got to go to work, will come back to this soooooon.
Roy.

Mecchanica · 10-30-2006

Don't put the 20 wt in the primary for the 70 and later engines IF you still have the factory arrangement in place where the engine and primary are connected by virtue of eliminating the left main bearing oil seal and drilling three small level holes in the case. This allows the engine to breathe into the volume of the primary case, but means that the engine and primary oil mixes. So use the same-o oil. This argues for a non-energy-conserving oil, as these have solid additives which can imbed in the clutch friction surfaces, and it argues for a thinner oil, such as 10-40 synthetic or 10-30 in winter. I use 10-30 all the time here in the tropics as it moves faster and therefore stays cooler at the load points and minimizes shear. The oil film strength nowadays is more due to chemistry than viscosity. The clutch also works better in a thinner oil. I use synthetic ATF in the primary of my 68. Flawless clutch action. "Thick" is the noise I get upon engaging first from neutral.