Convert/Cal II Auto drive system logic question

[brider]

I (mentally) committed myself to removing the tranny on my Cal II Auto to replace the TC-to-tranny input O-rings that I've convinced myself are leaking. I've written about the symptoms recently; basically, the TC is losing fluid, (lack of) fwd motion becomes intolerable, while all else (pump, drive key, hoses, fluid level) has been checked and found to be good.

Without re-hashing all the symptoms and what I've done to pinpoint the source of the problem, can anyone tell me WHERE the hyd fluid goes if it DOES leak by the internal O-rings?

What would help me here is a diagram of the fluid flow in the system, and the function of the "return" hoses.

There is a banjo bolt connection at the bottom of the cases that I believe returns to the fluid tank, and there is also a drain hose that would just drain to my garage floor.

Q: If fluid was leaking by the internal O-rings, would it be returned to the tank, or would it drip out onto my garage floor?

I've seen no evidence of leakage on my floor.

[rodekyll]

If the internal o-rings fail the leak would return to the tank.  If the t/c was not centered or is missing the nose bushing, or if the t/c seal fails the leak would be external.  If the bearing seal fails the leak would be to the clutch cavity.

Here is the flow diagram:

tank -> pump -> upper banjo (rt side) -> T/C -> lower banjo (rt side) -> cooler -> tank
                                                     -> drive shaft O rings and bearing -> bottom banjo under transmission -> tank

Notice two things:  First, the two different flow circuits through the transmission.  Second, only part of the returning fluid gets cooled.

As fluid enters the transmission via upper banjo it has two routes back to the tank.  The routes are holes drilled through the fluid drive housing casting and through the drive shaft sleeve.  This is why there are four wrong ways to install that sleeve -- you want the holes to line up and they only align one way.

[brider]

If the internal o-rings fail the leak would return to the tank.  If the t/c was not centered or is missing the nose bushing, or if the t/c seal fails the leak would be external.  If the bearing seal fails the leak would be to the clutch cavity.

Here is the flow diagram:

tank -> pump -> upper banjo (rt side) -> T/C -> lower banjo (rt side) -> cooler -> tank
                                                     -> drive shaft O rings and bearing -> bottom banjo under transmission -> tank

Notice two things:  First, the two different flow circuits through the transmission.  Second, only part of the returning fluid gets cooled.

As fluid enters the transmission via upper banjo it has two routes back to the tank.  The routes are holes drilled through the fluid drive housing casting and through the drive shaft sleeve.  This is why there are four wrong ways to install that sleeve -- you want the holes to line up and they only align one way.

Ah!!!!! Very good diagram!

So,...the fluid that runs into, and is retained by the O-rings: Is the only purpose of the bottom banjo route to scavenge anything that leaks past these O-rings, or does this bearing you mention get a separate fluid supply that is scavenged back to the tank?

I think my logic for pulling the tranny and replacing the O-rings is still valid by your illustrations. At the very least, I'll eliminate THAT as a source of slippage, and service my swingarm pivot, u-joint and carrier to boot!

Much obliged,

[brider]

tank -> pump -> upper banjo (rt side) -> T/C -> lower banjo (rt side) -> cooler -> tank
                                                     -> drive shaft O rings and bearing -> bottom banjo under transmission -> tank

Just occurred to me: Wouldn't it be a valid check to make sure the pump is actually pumping at a high rate, to remove the upper banjo from the right side, or even the return to the tank from the cooler, and start the bike up and run it and see how "briskly" it pumps out? (into a container, or course...)

[rodekyll]

There are two banjos on the bottom of the transmission.  One is way forward at the bellhousing.  This one drips if you have an external leak.  The other one has a metal pipe with a 90º bend.  This is the one returning to the tank.  It is actively returning fluid.  The bearing needs the lube/cooling.

Yes, by all means figure out some sort of flow test.  You will need to route both returns to your bucket or whatever if you plan a volume test.  I have never done one.  However, I do plan to measure the total volume of fluid in the system one of these days.

Another 'flow test' would be to simply open the cap on the tank and look.  If it's flowing there will be lively circulation in the tank that you can see.

[Vasco DG]

Another place tranny fluid will leak not is the clutch housing. Many people, myself included, have drilled a small hole in the bottom of the housing to allow leakage out. If it can't escape it can foul the plates, well, will foul the plates and cause slippage. It manifests itself as staining around the joint but the wretched clutch compartment can be full of fluid and not drip a lot as it is sealed fairly effectively!

Pete