2002 harley fat boy
on my fagbnoy I have a leak I cant find. Itgs not the transmission cause the fluid is red.Its not the shifter cause again the transmission fluid red,Its not the primary cause it right up.. Its the motor cause the oil is 50 weight and its clear. I have looked every where but I cant find where its leaking from Its leaking on the shifter side cause its on the trike axle (It has the frankenstien kit installed on ot) Igts not the rear end cause its only on the front of the axle where there are no seals and it doesnt have oil in it just grease. Any help would be appreciated.
How are you sure it's an engine oil leak, if you can't find a source...??
Oil, regardless of original color, and after being left on a surface for any amount of time, will attract dirt and road grime which changes its color.
If you are sure you using engine oil, when you add oil, where on the dipstick do you bring up the oil level to? Halfway between "add" and "full"..?? Three quarters between "add" and "full"..?? All the way to the "full" mark?
Once at that level, how many miles do you ride before the oil level drops to the add mark on the dipstick?
The general procedure when an oil leak is suspected, is to clean the entire engine and bottom of the bike, Then inspect frequently after riding, in an attempt to find the source of the leak, before it's spread all over the bottom of the bike.
Good luck and keep us posted...
Oil, regardless of original color, and after being left on a surface for any amount of time, will attract dirt and road grime which changes its color.
If you are sure you using engine oil, when you add oil, where on the dipstick do you bring up the oil level to? Halfway between "add" and "full"..?? Three quarters between "add" and "full"..?? All the way to the "full" mark?
Once at that level, how many miles do you ride before the oil level drops to the add mark on the dipstick?
The general procedure when an oil leak is suspected, is to clean the entire engine and bottom of the bike, Then inspect frequently after riding, in an attempt to find the source of the leak, before it's spread all over the bottom of the bike.
Good luck and keep us posted...
I am pretty surer it is engine oil .Its all over the rear end axle of the trike. The trany oil is right up to te full mark and the primary oil is right up to where the manual says its supposed to be I ride aboit 1000 miles before it goes down . I fll to the K mark which is a little bit under the 1/2 full mark but not much under..Yesterday I washed the bottom of the engine and trany real good. I also washed the top of the engine and tomorrow I will ride the trike to see if I can see where it is leaking from
Well I found my leak after washing the bottom of the motor ant trany. Its leaking from the primary out of the clutch seal behind the front pulley. Any one know if you can take the pulley off without taking the whole trike kit off? Can you just turn the adjusters on the belt and lossen iy enough to get the belt off the front pulley? Its a pain to get the trike kit off but it can be done if nesasary. I know the inner primary has to come off to change the seal but am wondering if you have to take the trike kit off also?
Well I found my leak after washing the bottom of the motor ant trany. Its leaking from the primary out of the clutch seal behind the front pulley. Any one know if you can take the pulley off without taking the whole trike kit off? Can you just turn the adjusters on the belt and lossen iy enough to get the belt off the front pulley? Its a pain to get the trike kit off but it can be done if nesasary. I know the inner primary has to come off to change the seal but am wondering if you have to take the trike kit off also?
Not sure how the trike kit fits into this whole scenario, but on a normal 2002 Fat Boy....
That seal (#13 first pic) can be replaced, but you need to remove the primary cover (#21), and the primary housing (#24). You don't need to remove the trans pulley, or the belt, to do it. That Inner Primary Seal is in the housing (#24).
While it's apart, you can check the inner primary bearing (#11 pic above) and its race on the trans shaft (#5 pic below) to see if they need replacement also.
Might as well check the shifter shaft seal (#17 pic below) as that is also a chronic leak issue.
I hope this info translates to the trike kit, and you find it useful.
Good luck with the leak repair.
Last edited by hattitude; Jul 27, 2025 at 11:24 PM.
tanks for your aadvice. got it fixed today, no more leaks. but it cost me $1,282.00.didnt have to remove the rear end
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He told us in #5....
But after re-reading it, and seeing the cost, I'm wondering if it was the inner primary seal as I thought, or the main trans shaft seal behind the front trans sprocket?
Last edited by hattitude; Jul 29, 2025 at 08:34 AM.
Wow, $1,282.00 to replace a $7 seal...... Makes me glad I do my own work..
I'm curious, was it the inner primary seal, or the main trans shaft seal behind the front trans pulley?
Anyways, I'm glad you got it fixed...
Last edited by hattitude; Jul 29, 2025 at 08:37 AM.










