44 Chief oil seal

[Rowdy]

What stops the oil coming out of the primary side of the crank shaft? I can see something that looks like an oil seal on the engine sprocket, but what stops the oil from coming out from behind the thick washer, next to the bearings And filling up the primary case?

[T. Cotten]

What stops the oil coming out of the primary side of the crank shaft? I can see something that looks like an oil seal on the engine sprocket, but what stops the oil from coming out from behind the thick washer, next to the bearings And filling up the primary case?

Rowdy!

Sorry nobody more knowledgeable replied...
I fear the cork seal is all there is.

Since Indian literature that has survived is pitiful,
I often refer to http://www.jerrygreersengineering.com/catalog.php

Good luck!

...Cotten

[Rowdy]

Thanks for that. I have been using the Greer catalogue to rebuild the Chief and yes it does show just the cork seal. I still can't work out how to stop engine oil going into the primary or worse still primary oil contaminating the engine oil. Oh well onwards and upwards!

[T. Cotten]

We hope, Rowdy,..

That the cross-contamination is minimal.

Apparently it was, or the machines would never have become icons.

And there would be lots of 'better ideas' on the market, for sure!

....Cotten

[Lyle Manheimer]

Rowdy,
Tom is correct, the cork that fits into the machined recess in the engine output sprocket is the seal. Hard to believe right? Keep in mind that the Chief engine is a dry sump engine and that when running it operates with a small amount of oil in the sump of the engine and that is regulated by the return portion of your oil pump. When the engine is running the oil is constantly circulating and that level is kept constant in the sump. It is at best not a great seal but it works as long as the cork is not dried out and is still pliable. I would doubt that oil from the primary would not be drawn into the engine as we are not dealing with a high volume return pump. Both engine and primary use the same grade of oil if my memory serves me well. If you are concerned about that why not add an in tank oil filter, a good idea anyway.
Keep in mind that 20 years later HD used a circulating oil system that lubricated the engine and the primary chain with the same circulating oil and it was all filtered when it returned to the oil tank. Was that a great idea? I guess not as a few years later they opted for three separate systems, but apparently engineers felt it was a good idea at the time.

[cdf6333]

Theoretically, the cork "seal" pushes the thick engine end play control thrust washer against the case bushing so no oil can get thru. Your end play has to be close to the .005" to .010" for the cork to work well. I use an oil ring instead. If your breather valve is doing its job, and if the rings and guides are good there's no crankcase pressure to push oil thru. The left case bearings are only lubricated by the tiny drip hole above the case bushing. Miniscule amounts of oil get down there.
Bad rings or guides allow blow-by which is crankcase pressure, which also contributes to oil leaks. Cars use a PCV valve , which is similar to our breather, to control this.
Plus usually the engine oil and trans oil on a 48 are the same, no problem with oil mixing even if it did happen. Metal filled trans and primary oil getting into the engine oil would be a big problem!
In 1953 when Indian used 10W oil in the primary Indian used a full metal/rubber seal at the case bushing.

[Rowdy]

Thanks for that cdf, I was advised to use automatic transmission oil in my primary, that's why I was worried, it would be a lot easier to use engine oil in my primary case. My bike is a 1944, I presume that it's the same as a 48. What is an oil ring?

[PRG]

Howdy sir,

Recommended primary oil should be taken in context with what type of clutch material you are using in conjunction with whether you have sealed your primary from the transmission as Bob mentions above for later models. About the only app I’d go with ATF is a metal based clutch like the sintered bronze in a Qua and if the transmission was sealed. Harley Sportster primary/trans oil is light enough for the clutch release those recommending ATF are looking for while providing a measure of shear resistance needed for applications where the operator spends a lot of time in 1st and 2nd gear (direct gear to gear) and/or is hauling a heavy chair in a shared primary/trans environment.

You often hear about locating oils having ZDDP content now pretty much eliminated from street formulations to protect catalytic connverters. ZDDP provides scuff resistance for flat tappet motors at the cam/lifter/rocker interface which is far more lightly loaded than the 1st/2nd gear teeth interfaces and therefore I’m not a big proponent of engine oils in our vintage machines when there are more suitable options our forefathers did not have 70 years ago.

Both my 346 and 348 are sealed running the above HD in the primary with Qua’s and then 80-90W hypoid in the trans. And in a nod to vanity - acknowledging the lost efficiency of stirring this higher content at elevated road speed - the latter is filled to just about covering the cluster gear interface with the slider for quieter operation in lower gears.

[cdf6333]

The oil ring is the lowest of the 4 piston rings, if that's what you mean. Don't run ATF in the primary, your trans gears will friggin hate you. You could add an once or two, but the trans gear lubrication is a lot more important than clutch dis-engagement. In Florida I run the 50W in trans/primary, just like the old manual says.

[Rowdy]

I didn't think this was going to get so technical, (thanks Peter), I think my best bet would be to go the 50w in the gearbox and primary and maybe fit a crank case breather and a breather valve off a 52-53 Chief for the primary. What do you think? Im building this bike as a rider and not a 100% original trialer queen.

[PRG]

Howdy sir,

Unlike Vincent’s, Commando’s and a few others that shall remain nameless, requiring breather mods for even moderate riding, unless you’re going to be running down the Interstate on a 4 speed at 75mph for extended periods of time you can keep it even more basic than that. Stock breather on the motor (no need for the variety of aftermarket duck-call sounding contractions replacing your timing plug) and no need for one on the top of the primary if your primary and trans are not separated. The small vent hole on top of the shifter tower is more than sufficient

Unlike many OHV motors of the era sealing a flathead was not really a problem and Indian really had this under control. Most people mistake primary leaks at the generator drive for thermal expansion within the primary or escaping crankcase pressure at this location. Without any form of sealing and using only a reverse spiral in the bushing to draw oil back into the primary if that bushing was worn from mileage or running excessively tight generator belts it will wear and leaking oil would/will mist back coating the battery area and tool box. Greer sells a small modern seal that cures it on new bushings and allows more latitude for wear on old ones.

[gsottl]

it is no fault and easy to use the 52/53 drive shaft seal on a 1944 Chief....just need to use the narrower roller bearing spacer......

[samsmc1]

This thread opens up a new can of worms for me. I have a very experienced acquaintance that advised me against sealing up my primary and trans so I could use three grades of oil and keep them separated. I have already done this on the '48 Chief I'm assembling at this time. I was concerned that I may have screwed up by not researching this further before making the necessary changes. Do any of you have experience with the pro's and con's of this arrangement?
Thanks
Sam

[tfburke3]

I think the factory must have thought that heavier gear oil in the trans had benefits.I never had that set up and neither did anybody else before 1950, and never had trans problems after a rebuild.
I wouldnt worry about it.Save the energy for your first valve job.
Also not a fan of mainshaft seal that uses narrower spacer as it increases the overhang of the sprocket.
Tom

[PRG]

Howdy Sam,

And Indian also fitted a clutch brake, so you can see where that program was going.

Cons? None once done. Sealed 348 89 inch hot rod 22 years, stock 346 15 or so now. This falls under the heading of refinement opportunity, not absolute necessity, and is part of a list of small changes that result in in level of usability/durability the original designers could not have envisioned nor had the resources/materials at the time. I live in a large city and only ride antiques as one would a modern machine night or day. The ability to flick in/between gear(s) quickly on 6 lane streets in unforgiving traffic without clash or resistance due to light primary oil, only 8 springs on the 346 and 12 on the 348 on lighter tension bronze clutches while exhibiting little wear on 1st and 2nd gear over thousands of miles using high sheer hypoid oil is complete upside to the equation.

Unlike Indian back in the day who likely preferred you wear out your machine relatively quickly to get in the mindset to buy a new one, my first custom made bicycle sits out in the shop bought 46 years ago sitting next to one of its brothers, a car still on the road 36 years later. These machines can be made to last while operating far better along the way, this is just another improvement in that quest....if one is so inclined.