Mystery of transmission fluid

[Dark Horse]

My 2013 Fat Bob is now 'losing' just over 100ml (3.5fl.oz.) of transmission fluid for every hundred miles.
There isn't the slightest sign of a leak under the bike , nor any drips on the garage floor !
Checked primary drive fluid level and it's always the same , so it's not finding its way into there ! HD dealership are mystified too !
It's NOT 'human error' coz it's happened four times now !
Any suggestions as to what's going on would be greatly appreciated guys !

 

[joel]

Can it get in the engine oil somehow?
How about a vent hose from the transmission?
If there is 1 take a close look at it maybe use a qtip to push inside the hose to see if it gets wet.

 

[TQuentin1]

How are you measuring that?

Cheers,

TQ

 

[Jeff Klarich]

Impossible to lose that much in only 100 miles of riding without 1 heck of a leak or it's going somewhere else.
You may want to drain the tranny and fill it with Redline heavy, it's pink (pepto bismol) color should be a little easier to trace not to mention it's a great product.

 

[tourbox]

Good suggestion from Jeff. The tranny can only leak from the left side(2 seals), right side(trap door and clutch release cover), top cover gasket, gasket to oil pan(mounts under tranny) and a gasket between tranny housing & motor, that started in '06 for Dynas. And the vent hose. That's all I can think of.
tourbox

 

[Dark Horse]

Can it get in the engine oil somehow?
How about a vent hose from the transmission?
If there is 1 take a close look at it maybe use a qtip to push inside the hose to see if it gets wet.

Can it get in the engine oil somehow?
How about a vent hose from the transmission?
If there is 1 take a close look at it maybe use a qtip to push inside the hose to see if it gets wet.

Good suggestions , but I don't think transmission fluid can reach the engine. They're different compartments. Engine oil level remains constant anyway.
The breather tube is off at the moment because I'm waiting for a new one (old one perished!) but there is no sign of leakage there.

How are you measuring that?

Cheers,

TQ

I measured a set quantity into a measuring jug then recorded how much fluid was required to bring the level back to normal.

 

[TQuentin1]

Does that mean you are draining your tranny every 100 miles? Are you replacing the fluid or reusing it?

Good idea that Jeff mentioned above to use a fluid that is easy to identify by color. See where that shows up. You might change the engine oil and Primary fluid so that they are clean and will show the contamination with the colored fluid you put in the tranny. But that is a lot of fluid to be loosing without some other fluid reservoir just overflowing!

Cheers,

TQ

 

[dolt]

Who checks transmission fluid levels every 100 miles? One of my bikes has about 35k miles on it and I have never checked fluid level, even after a change. No way a tranny leaks that much without leaving some physical trace of the leak no matter what tranny fluid the OP uses. Tourbox identified all the locations where tranny fluid can leak out and if there is no physical trace of a leak at one or more of those locations, the tranny is not leaking; tranny fluid does not evaporate. The OP should stop checking every 100 miles and put 500 miles on the bike, check and report.

 

[Dark Horse]

Good suggestion from Jeff. The tranny can only leak from the left side(2 seals), right side(trap door and clutch release cover), top cover gasket, gasket to oil pan(mounts under tranny) and a gasket between tranny housing & motor, that started in '06 for Dynas. And the vent hose. That's all I can think of.
tourbox

Could transmission oil possibly find its way into the oil pan ?
Thing is , oil level remains constant !

Impossible to lose that much in only 100 miles of riding without 1 heck of a leak or it's going somewhere else.
You may want to drain the tranny and fill it with Redline heavy, it's pink (pepto bismol) color should be a little easier to trace not to mention it's a great product.[/QUOTE

I've heard it's good stuff !

 

[Jeff Klarich]

If your oil level stays the same then no it's not seeping into the motor oil.
According to your 1st post you said you had to add 3.5 oz about every 100 miles, it's gotta be going somewhere.
I would suggest you use a dye in the tranny fluid or what was suggested in post #4 to try and see where it's going.