I just changed the fork oil on my '02 Ultra and I'm glad I did. I had Race Tech service my forks and put their gold valve in during my first fork oil change. Ever since then my forks have felt like they were bottoming out a little too easily. I measured the fork oil level before I dumped it out and found that both forks were running 2 inches (about 3 ounces) low on oil. I don't know if this was a big problem or not, but from everything I have read, it can't be good running your forks low on oil.

This was my first time servicing forks and I would do it again. You don't need all of the special tools they call for in the manual. I made a fork clamp out of a wood clamp (or you can buy one on E-Bay) and I bought a Motion Pro Fork Level Gauge to ensure I was putting the proper amount of oil in them.

The only special tool I couldn't find or easily put together was the Damper Rod Extension Tool. You only need this tool if you have the cartridge in your left fork, which mine does. I think Road Kings have two conventional forks. This tool, which Harley says is "commercially available", is a coupling nut and a threaded rod. You screw it to the top of the cartridge (damper) rod and use it to pump the old oil out and the new oil in. The forks are made by the Japanese (Showa) so it is a metric thread size. You may be able to find the coupling nut and rod in your area but I couldn't. I was able to get away with using SAE sizes without messing up the threads but I would NOT recommend it. I believe the appropriate size is 10 mm, fine thread. I think I used a 3/8" X 32 but I had to be very careful. I think this rod will work http://www.fastenermart.com/html/RD196-5222.html but I can't find anywhere that sells the rod and coupling nut. Some places sell what I think is the correct size but they will only sell in bulk. If anyone has found the appropriate hardware to fashion this tool I am anxious to know where I can get it.

I service my forks according to the service manual; every 20k miles. The oil was dirty but it wasn't disgusting. I did take the time to flush as much of the old, dirty oil out as I could before I reassembled everything.

I have read the thread about changing the fork oil with the forks on your bike but I wouldn't do it or recommend it. With the forks on the bike you really can't tell what your oil level is. If you drain the oil and put in as much as you took out you will end up with the same level, but if the fork oil level was low when you began, you will only refill it to the same low level. Also, with the forks on the bike I don't see any way you can get all of the old, dirty oil out of them without spending a LOT of time putting oil in them, pumping them a lot, and repeating the process. Besides, it doesn't hurt to pull your forks every couple of years. It gives you a good chance to take the front end apart and look everything over.

But, then again, everything I just wrote could be wrong.

 

my manual says 50,000 i have 21,000 on them now i think i will change them at
25,000 to be safe -ride safe

 

Do like I did! At 20,000 miles have chrome forks put on the bike and you get a free fork oil change!

 

+1, I agree.