Hi,

I'm riding a borrowed FXSTC (99) that has not had great maintenance, but enough that it runs and rides well. The engine oil was black as night so I figured the other fluids were over due as well.

The trans oil did not register on the stick, instead of changing it I added Formula + just to see how low it was..Took over half a quart just to get on the stick. The primary oil was dirty but not awful and not much metal on the magnet but it was overfull with the bike level!!!???

Questions:

Can the trans oil leak out into the primary? That would explain the low trans level and overfull primary..The bike is dry..

Got a new Derby cover gasket, looks like a small frisbe, old one was an "O" ring. Tried to re-ue the ring and it seeps a tad. Do I discard to O ring when I use the new gasket..(saw this answere on here but can't find it).

Someone want to run chain adjustment by me, or how loose is too loose.

Thanks
Doug,

PS: No book, not my bike (yet), just trying to keep it up, hate to see a fine machine neglected.

 

Sounds like it has a tranny out seals leaking. Yes tranny fluid can leak into the primary. No you don't keep the "o" ring on when you use the other gasket. To adjust the chain, you need to raise the rear wheel up, pull out the spark plugs and put the bike in 5th gear. rotate the tire untill the chain is at the tightest point on the top, you want to have about 1/2 inch of play in it at.

 

99?...

The only way the trans fluid can get over to the primary is if it were filled stopper full and ran thru the clutch release rod bore. (that's where the primary vents, back thru the trans.) and then it'd only get a little - not enough to ever know.

It has a serious transmission leak. The main seal will leak it out to a rather low level and hopefully that's it. Not a hard fix, just a lot of labor. The fluid would leak out behind the front pulley. If it's leaking out the mainshaft seal, there would be fluid all over the backside of the primary and front of drive pulley. And in that case it would take a longer time to leak it out to that low of a level. (but since it's dry, it could be leaking somewhere else)

The over full primary is caused the main engine seal leaking putting engine oil into it. That's the only way. Again, cheap fix other than labor.

The trans leak would be easily addressed while into the main engine seal job. Remove the inner primary and remove the front pulley and you're there.

You do not use the clutch cover o-ring with the updated cover gasket.

Primary chain adjustment will be easy as you go back together with the other repairs.

 

Thanks for the replies

Thanks for the gasket and chain info.

Doug

 

Hey Doug,

The info in my long-winded post was all correct, generally speaking. Also, the primary fluid will most often migrate into the engine oil with a bad main engine seal, rather than oil into the primary.

However I didn't give thought to the possibility that someone simply serviced the bike incorrectly. Thank goodness my enthusiasm in offering information didn't alarm you into disassembling anything

Considering there are no leaks after properly filling everything, regular checks on all the fluid levels is the sensible course of action.

 

t150, thanks for taking the time with that "long winded" post..LOL, all info is welcomed. I'm just learning, don't even own a bike yet, but I read through this and other sites regularly. I hope to buy this bike but if not I'll have a good idea of what to look out for on the open market.

There is a good chance he serviced it wrong but I think it's hard to under fill the trany, we'll see..

Doug

 

Since the engine oil is pressurized and the primary isn't, it would seem possible (at least to me) that the oil would leak into the primary.

 

True and not true.... The oil is pressurized in the journals but moving freely in the crankcase and cam side, partly as liquid and partly vapor.

First, realize the flywheel and cam sections of the engine case are separate, and though not sealed, are only connected by the openings at the breather gear and the pinion bearing.

When the pistons come down, reducing the area inside that side of the engine, the breather gear opens and vents the displaced air/oil mix to the cam side. When they are on the upstroke, the breather valve closes and by the pistons upward motion, creates a vacuum on the flywheel side which pulls oil vapor up onto the cylinders and underneath the pistons for lubrication of them, as well as the wrist pins. Granted, gear-driven breather timing is a bit more complicated and I do not have the degree figures in front of me, that's just the general principle....

There is seldom more than 1/2 pint liquid oil on the flywheel side and it is connected to the primary via the sprocket side of the flywheel which is much higher than the liquid oil level ever is in the engine. When the seal fails, the vacuum created by the piston upstroke will draw a tiny bit of whatever amount of oil that will leak by that seal because primary fluid is constantly thrown everywhere by the chain. That's why the seal is installed what would appear to be backward (lip/spring out) on a wet primary bike. A dry primary bike is another story........

 

Good technical discussion. You guys know your motors. One possible piece to this puzzle, if I put in the recommended amount of transmission oil as specified in my 2006 softail manual (22oz), the oil will not register on the tranny oil stick. So now I always put in 26+ oz, screw the manual on this one.

 

Are you checking the tran fluid on the jiffy stand? My manual says to check tran with bike straight up. That would make quite a difference.
Just throwin it out there.