[Lake Marine]

When I slide a stick of 1/8 TIG wire through the primary filler plug and down behind the chain to the bottom of the case to check primary oil level Im only getting ~1/8" on the stick. Im quite certain getting all the way to bottom of case and checked it before and after a ride this morning and its the same. I rebuilt my clutch a month ago but I do not remember pulling the 71-1072 breather baffle plate so I dont think I could have pulled that oiler line off (assuming it has one). I also just noticed my 71-1072 Breather Baffle Plate doesnt have an oil "tray" like online replacement parts which show it but as mentioned (see photo) mine doesnt have one nor do I see a hole where the oil would come through even if it had the tray.
My parts manual shows what appears to be the tray and all replacement parts online show it. (I also looked in the '79 parts book and it shows it as well)
Anyway, should the plate installed on my bike have a tray or at least a hole in that vicinity for that brazed tube to flow oil through into the primary?
If not how/where does the oil flow into my primary?
Any ideas as to why it only measures 1/8"?
(Maybe Im looking at this breather plate all wrong... i seem to do that a lot lately...must be the damn heat here!)

Since I lapped my primary cover and installed new gasket I have not had any leaking or oily mess anywhere under the primary, rear rim, chain/sprocket and left muffler area as before and all are clean. 20 miles out on ride today I fueled up and looked for any signs of leaks on the concrete pad at the pump and not a drop. About every ride where I can I'll sit at a stop for a few then roll back and look for leaks and nothing noted so I don think i have any massive leakage while under way.
Thanks for any help. LM

 

[newsh]

The purpose of the little tray and tube is to catch oil drips from the top run of the chain and feed it directly to the front sprocket. Nothing to do with keeping the primary topped up.
Your bike doesn’t have this feature and never did, as the small boss on the inner casing has not been drilled and tapped for the clip which holds the tube.

When you rebuilt the clutch did you pour the correct amount of oil into the primary?

 

[Happyfeet]

Here's a pic of my 1979 T140E. Ditto to what newsh just said. The engine oil is shared thru the bearing and 3 little holes below the stator mounting studs. I believe the holes are intended to somewhat maintain the level. You fill the primary with the specified amount from the workshop manual and then it travels between the primary and crankcase. My suspicion is there isn't really a large amount of exchange between the two. Someone with more knowledge might correct me....

 

[rambo]

Its a self topping up primary. Put too much in and it will drain back into the engine fairly fast until the level is right. Oil level in there is something i rarely check as i have no leaks and know it tops itself up. Same with gear oil, if no leaks, no need to check level as long as half a litre was put in.
I would be very surprised if a lot of oil went through that bearing and returned back through the three holes. Just mist is what i would expect to be blowing into the primary. You would not want a lot of that primary clutch dust getting back into the engine oil. Pic shows an engine with the sprocket oil pipe

 

[Lake Marine]

When you rebuilt the clutch did you pour the correct amount of oil into the primary?

I put 12 oz in the primary (manual says 5/8 pint (350cc) on initial fill) I did a complete oil change when I finished the clutch so I considered that an initial fill. Ive probably got 1000 miles on the clutch now.
Ahhh... I thought it was a feed line on the other side since I couldn't see it. Interesting how the 77, 78, 79 parts manuals show the tray on the plate and all of the ones i saw on the web have it. Curious as some have and some dont and/or it was discontinued and manuals were never updated.

The engine oil is shared thru the bearing and 3 little holes below the stator mounting studs.

So oil flows through the left main bearing and back over through the 3 holes not seen as they are behind the chain adjuster.

Im still kind of stumped as to why im only measuring 1/8"...as I understand it should be ~1/2" roughly measured.

 

[TR7RVMan]

Hi Rick, My ‘73 has the oil cup. I thought the kept the oil cup until the new version adjuster came out in 80 or 81. Obviously I was wrong!

The cup was for the chain oil tube. It was determined by factory to not be needed.

It is said the 3 little holes played an important part in chain oiling.
These holes are well above the oil level in primary.

I do not know how oil level is maintained. I just know that it is. I’ve checked several bikes. They all run about 1/2”.

Before ‘76 the primary cover did have drain plug. You had to drain via chain adjuster plug. I stared suctioning primary out through filler hole as adjuster plug is a pain to access. Finally I started siphoning oil into a baby bottle so I could easily measure what I drained out. Put same amount back in.

So I use 1/4 tube for dip stick. I marked it at 1/2”.

Maybe for some reason the welding rod doesn’t read the same? What do you get if you pull drain screw on side?

I’ll have to get to pc to post photo of the tube down filler hole.
Don

 

[StuartMac]

Hi LM,

I put 12 oz in the primary (manual says 5/8 pint (350cc) on initial fill)

You're reading the wrong manual ... '78 Triumph Owner's Handbook, . pdf page 8 or paper page 6:-

CAPACITIES
...
Primary chaincase (Initial fill) - c.c. ... 150[my stress]

... I appreciate the workshop manual says 350 c.c. but:-

. Owner's Handbooks were reissued every year (albeit misprints weren't always corrected ... );

. otoh, Workshop Manuals were updated with corrected pages certainly for several years, depended on a human fitting the corrected pages;

. the liquid oil in the primary is only to lubricate the primary chain and the clutch rollers.

Interesting how the 77, 78, 79 parts manuals show the tray on the plate

Common. Parts listings are produced by manufacturers to help dealer staff find parts for customers; certainly before the advent of CAD, what they never were always was accurate illustrations of parts - they were produced and printed as cheaply as possible, printing plates for illustrations were the most expensive so, if the same illustration could be used for parts either superseded or differentiated by listed part number, it was.

all of the ones i saw on the web have it.

Because around forty years after the original manufacturer closed, the parts supply industry tries to make as few different parts as possible.

So oil flows through the left main bearing and back over through the 3 holes

No. As your bike's engine is 'dry sump', by definition there shouldn't ever be much liquid oil in the crankcase at any time. So no reason for it to go into the primary; in any event, you absolutely do not want liquid oil "flow[ing] through the left main bearing" when the engine's running, it would sap power and heat up the oil for nothing.

All triples and '70-on twins, the crankcase vents through the primary so vented oil droplets can condense in the primary, rather than being vented to atmosphere (pre-T140E twins) or into the airbox. In addition, the oil tank (separate or frame spine) vents into the primary. On '70-on twins, the three small holes between primary and crankcase - visible behind the alternator stator and chain adjuster - are specifically to prevent the primary oil level ever reaching the main bearing, for the reason in the previous paragraph.

I put 12 oz in the primary (manual says 5/8 pint (350cc) on initial fill)

'78 Triumph Owner's Handbook

CAPACITIES
...
Primary chaincase (Initial fill) - c.c. ... 150

Most of the 350 cc. is in your bike's frame spine ...

Hth.

Regards,

 

[Lake Marine]

Maybe for some reason the welding rod doesn’t read the same? What do you get if you pull drain screw on side?

Hi Don - I tired it with a thin blade screwdriver first but that was showing an 1/8" so thought possibly wasn't hitting the bottom and that's why i went to the rod. Ive checked and re-checked and I can clearly see ~1/8". I pulled the drain plug prior to pulling the cover when I rebuilt the clutch but hardly anything came out due to the gasket blocking the drain I guess. When I popped the cover off I'd guess I had 6 ounces (just guessing by memory). I could maybe try to drain it next week (I did trim the gasket a bit in that area but unsure if enough). Another thing to note is I am on the center-stand and with my forks she does sit high in the front so maybe more oil is pooling to the rear and the measurement isn't really true. I don't know.

You're reading the wrong manual

Hi Stuart - Well that figures. I have two original handbooks and have it electronically but for whatever reason I always forget and look at the other workshop manual.
I've always been impressed by Triumphs quality pre-cad illustrations but maybe they could have at least updated the parts list as it clearly shows and gives P/N's for tube, clip, washer and bolt! I'm sure this isn't a common part needing replacement (unless someone lost it) so I see what you mean about keeping a design with tray verses two parts to be manufactured and stocked.
Someone mentioned oil flowing through a bearing in that region so I assumed that was the one they were referring to. I'm not sure the path of the vented then condensed droplets but it doesn't seem to be adequate to maintain the remaining amount of the 350cc i poured in and I don't have any primary leakage.
By me adding too much (350cc) at initial fill and if that over abundance reached the three holes it would have drained back to the OIF spine leaving the remainder which seems like would be more than the 1/8" that I'm measuring.This bike has had a slow drip for the ~37 years it lay dormant (like the USS Arizona) and after lapping the sump plate and bottom case face along with the primary cover with new gaskets on those and the outer gearbox cover its finally not leaking. (Well that's a lie as I am getting some weep around the head bolts and rocker shafts).
Unless the primary level is catastrophic...I'm not going to worry about it too much...and will try to measure amount next time I pull the cover at some future time TBD.
Thanks for everyone's input!
LM (Ricky)

 

[newsh]

I think you might be on to something with the centre stand, if the front wheel is off the ground then the oil will pool at the back of the primary.

 

[Lake Marine]

I’ll try to check it off the stand Monday.

 

[TR7RVMan]

Hi Rick, The 1/2” is with a stock bike sitting level on its wheels.

I’ll say this. Back in the day we installed 6” over forks on occasion. 4” was more the norm. This was on ‘70-72 bikes with primary breather. Caused no problems with motor, clutch, primary chain.

We drained primary. Put 350cc in primary. Left frame to about low line on dip stick. Road 10 miles. Topped oil.
Pretty common to overflow frame next time we checked oil. Back in early 70s we didn’t have a clue on these bikes like we do now.

Might be hard to get bike level to check oil level by yourself.
Don