I started getting the bike ready for spring, and found most of the oil had drained out of the tank through the engine into the primary case, Now I know this is two different issues.( check valve and engine seal) but the question is, do I have to change the main seal? would it be fine if I just fixed the oil pump check valve? 84 FLHTC.
TIA

 

You may not need to do anything with the check valve, sometimes the problem is just a bit of debris causing the ball to not seat properly, once the engine runs a bit, the problem may be gone.

Is the primary sealed or still using the hoses to connect the primary and engine lube system together?


If your primary is still original `84 (dry clutch) configuration, the oil in the primary could be from a bad engine seal, or an air leak in the primary not allowing the oil to be scavenged back to the engine, or a kinked or obstructed hose etc.

I would drain the oil from the primary, make sure there is about a quart of oil in the tank and fire it up. Put a drain pan underneath the breather hose to catch the oil barfed out of the breather. Running a few minutes should scavenge the oil out of the crankcases and give you a better idea if there really is a problem.

 

I always thought running engine oil through the primary was a bad, make that very bad, idea. Clutch goo isn't a good fit with engine bearings. so that's one of the first things I changed when I bought the bike a few years back.

 

My first Harley was a shovel with a dry-sump primary, which is what Dan has described. The pump supplied oil to the primary chain and evacuated it. Engine oil change intervals were quite short, which addressed the clutch goo problem!

 

So.. what you guys are saying is the engine seal, behind the compensator, behind the stator, can stay. is fine, I don't have to change it? Cause I think it would be a P in A to do.

 

If I am right about what I said above, the primary should be air tight, so nothing can get in or out. So I suspect that seal needs replacing. Oil should only get in while the engine is running.

 

I'm gonna follow this one, I may have a problem with my '98 engine seal. You guys are really helpful in saying what and how to check for possible problems.

 

Well the primary was tight, I don't know about air tight, it was holding 3 1/2 quarts of oil with no puddle under it. But to recap, it has been changed to ..wet? the oil lines from-to pump are both plugged off. Was reading in another thread about seal being put in spring out vs spring in because engine runs with vacuum in crankcase. So is there any way to test said seal or is the oil leaking out enough of a sign saying change it. As you can tell I'm hoping I don't have to.

 

So the primary is a sealed system, no longer connected to the engine lube system.

Which means the only way engine oil can get into the primary is from the left side crankcase, it could be leaking past the seal and spacer, or maybe one or more of the screws that hold the stator came loose.

Before you get too involved, you might just run it and see if the engine oil is still going into the primary.

If it is, it wouldn't be a bad idea to pop off the primary cover, remove the clutch and compensator, and change out the seal and spacer. Also make sure the stator mounting screws are still there and not loose.

As far as the direction of the seal, the service manual will tell you to put the spring in if you are using the old configuration primary (connected to the engine oil system), and it will tell you to put the spring out if you are running the new sealed primary setup.

I don`t think it makes any difference. I have the spring facing in on my engine (opposite of what the service manual says), and no engine oil has ever gone over to the primary.

 

Check your sprocket shaft seal (behind the rotor). Old cases with steel inserts have tendency to loosen them, I'm not sure if there's a fix for that. For newer cases (from 90 or so), a small pin through the seal side should solve the problem.

If the seal is in place but appears worn out, just replace it.