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Oil Leak

12275 Views 11 Replies 4 Participants Last post by  2002RoadKingCLa
I was wondering if one of y'all would be able to help a mechanical idiot figure out a problem. On my new Road King I've noticed that it drops about a drop of oil per hour it sits and for the life of me I can't find anything loose to give it an excuse for dripping. The bike only has 400 miles on it and it's been babied so far so I can't think of a good reason it should be leaking. Does anyone have any suggestions of what I could do to try to track down the problem? Or is this a normal thing? It's never happened on any of my other bikes, hence the perplextion on my end. TIA for your help.
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How about you tell us exactly from what area of the bike it comes from. If it leaks with the bike parked the most likely leak is from the primary, but you never know. Look at the bottom of the gasket between the inner and outer primary, the inspection cover and the derby cover.

Look under the bike and make sure it is not coming from one of the drainplugs on the gearbox pan, and in front under the oil filter adapter.

Engine oil would be going a little black by now, primary oil would look like engine oil but look clean and gearbox oil has a distinct smell to it.


It is definitely not normal.
Thanks for your help again Hippo! After looking at it with better lighting it seems like the oil is leaking from a little rubber seal behind the primary where it connects to the next part. I'm going to have to take it down to the dealer from the looks of it, but I can't get it in there until tomorrow. Would I be hurting anything if I added a quart of oil and drove it anywhere today? I probably won't anyway, but I'm just curious :).
You still didn't say what kind of oil, but if I had to take a guess from "a little rubber seal" behind the inner primary it might be the jackshaft seal, and it would leak primary oil. Sometimes they also blow a little oil from the gearbox vent if it was overfilled and it is pretty much in the same area.

Adding 1 qt to either the gearbox or primary would be way too much and they are really not that sensitive to low oil level. No way to check primary level without taking the derby cover off.

Just RTS (ride the sumbitch) to the dealer unless you are talking hundreds of miles, which would hardly be the case. May want to check engine oil level just in case we missed something and it's easy enough.
I need to read my posts before I submit them, I forgot to say that it was darker oil (so engine oil right?) that was dripping. I took the bike out for a couple miles to get the engine warm so I could get a more accurate take on what the engine oil level was and when I checked that it showed that it was slightly overfilled..maybe I'll get lucky and that will be the only issue. I'm going to take her down to the dealer tomorrow so we'll see what they say. Thanks again for all your help!
No problem. Dark oil would indicate engine oil, but it would be real strange for it to leak anywhere near the rear portion of the inner primary unless it's coming from somewhere else. I suppose that with Harley fluids the primary or gearbox oil could have turned somewhat dark in 400 miles, so it would be a question of degree.
Let us know what they come up with.
It ended up being a bad gasket in the inner primary. Warranty covered everything so I'm glad I got it checked out. Thanks for your help!
ok so i am gonna ask a really dumb question just so i can clear this up. my 02 classic is leaking from underneath as well. i checked it and not sure where its coming from but my best guess is where the primary case meets the bottom of the motor. i replaces the outer primary gasket but still leaks. how much more trouble is doing the inner gasket and is this something a learn as i take apart stuff mechanic can do himself. thanks for the help
ok so i am gonna ask a really dumb question just so i can clear this up. my 02 classic is leaking from underneath as well. i checked it and not sure where its coming from but my best guess is where the primary case meets the bottom of the motor. i replaces the outer primary gasket but still leaks. how much more trouble is doing the inner gasket and is this something a learn as i take apart stuff mechanic can do himself. thanks for the help
Here's my two cents: before you start opening your cases, make sure your tranny vent tube isn't purging. Sometimes when the transmission case is overfilled, excess gear oil will purge from the vent tube located on top of the transmission case. Depending on the orientation of the tube, gear oil could be venting and traveling down the backside of your primary giving the appearance of a gasket leak. I had the same symptoms and once I was able to confirm that the oil was not coming from my vent tube, I was able to diagnose it as a bad seal in the inner primary (shifter shaft seal); allowing transmission fluid to travel along the main shaft and leak down the backside of the primary. Also, check for oil on your belt. If you determine that it is an inner primary seal, it would be a good idea to have them all replaced while your outer and inner primary covers are off. I was also able to tell that it was tranny fluid because I use 75/140 gear oil in my transmission and it is much thicker than 20/50. Good luck
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Here's my two cents: before you start opening your cases, make sure your tranny vent tube isn't purging. Sometimes when the transmission case is overfilled, excess gear oil will purge from the vent tube located on top of the transmission case. Depending on the orientation of the tube, gear oil could be venting and traveling down the backside of your primary giving the appearance of a gasket leak. I had the same symptoms and once I was able to confirm that the oil was not coming from my vent tube, I was able to diagnose it as a bad seal in the inner primary (shifter shaft seal); allowing transmission fluid to travel along the main shaft and leak down the backside of the primary. Also, check for oil on your belt. If you determine that it is an inner primary seal, it would be a good idea to have them all replaced while your outer and inner primary covers are off. I was also able to tell that it was tranny fluid because I use 75/140 gear oil in my transmission and it is much thicker than 20/50. Good luck

thanks for the help. i know it is engine oil do to the color and smell and i have been checking the level. its slowly dropping. not enough to really cause concern but i am headed to sturgis again this year and i want to make sure we are goog to go.
thanks for the help. i know it is engine oil do to the color and smell and i have been checking the level. its slowly dropping. not enough to really cause concern but i am headed to sturgis again this year and i want to make sure we are goog to go.
No problem... the Needles Highway is the last place you want to loose your top end! If you have not done it yet, get out east to the Badlands and Wall Drug - some great scenery out there. I used to camp out at Sheep Mountain. Have a great trip and ride safe.

Just realized you are from Omaha so I guess you've been by the Badlands. DB
oh yeah. done that cruise. needles is fun but i just hate the traffic during the ralley. plan on doing a trip with my dad sometime when the ralley isnt going on so he can enjoy.
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