Fork Oil
Harley Shocks & Harley Chassis IssuesDiscuss Fork Oil in the Harley Tech & Harley How-to forums; My Harley Ultra has over 60,000 miles on it and I don't think the fork oil has even been changed (I bought it with 40,000 on the clock) and wanted ...
My Harley Ultra has over 60,000 miles on it and I don't think the fork oil has even been changed (I bought it with 40,000 on the clock) and wanted to know what opinions are here for best fork oil and for how often it should be changed.
BD,
Go Bel-Ray and go often. My two cents is if you ride hard and live somewhere that has big seasonal swings (MN, WI, MI etc) do it every or every other year. Yeah, its likely overkill but its cheap insurance from getting a bunch of condensation in there and your forks are so much more consistent with fresh oil. It all just works better.
__________________ Ding. 69 FLH 72 XLCH All Men Die - Few Truly Live
I believe it is every 20,000 per sevice manual. I did mine at 10,000 and 18,000. Both times the oil looked good. So in the future I will go every 15,000. As long as your seals are in good shape you should have no problem.
The only problem with that is you do not know if your seals are letting in the elements until you drain and look at the fluid.
Geez now I guess I will do every 10,000. Talk myself right into it. Harley fork oil is just fine unless there is some miracle oil that gives you a better ride.
The stealer told me I would need special tools and so forth. About $200 bucks. $170 is for labor. A couple bucks shop fees and a few buck for Oil.
Took me about 45 minutes. Thats only cuz I dropped a bottle of oil and had to clean it up.
my 07 FLH shop manual show some fairly extensive work accessing the caps on top of the forks. Unlike my old FatBoy I could just unscrew the top caps and put the new shock fluid in. With the bat wing fairing in the way I have not found a way to get in their short of taking off the fairing. If that is the case I'll just take it all apart at 50,000 miles and do the steering head and the entire front suspension. Can anyone give me a short cut as to how to get the fork caps off w/o tearing the fairing apart? Thanks.
Hd must have changed this area, to afford access to the cap nuts. I've not looked at the newer bikes. On my '94 ultra there's no way no how unless you remove the outer and inner fairings. Good for you if they have, cuz it's a real pain. Takes about 1/2 of the day on the ultra, and about 1/2 an hour on the heritage.
How much concern should we have for exacting measurements of fork oil? I have seen statements that we should pay attention to the oil level in the fork with a dipstick and such, right up to and including a fancy suction tool to precisely drain the level to make both forks equal? I am looking at putting Amsoil in mine and that is kinda giving me pause.
I use a mix-rite measuring cup. Once the bike is off the ground, I remove the fork caps. Then drain the fork legs, maybe overnight. I then measure each side's drained oil, check what the manual says, and I come up with how much I'm gonna put back in. Equally in each side. Don't just put in the 1st figure you come to in the manual- they give wet and dry capacities (dry as in new and clean of oil. Another figure is given for wet, that is, drained forks) to keep from overfilling. I've done my flhtcu and my wife's flstc several times with no problems. I think after the first change, there's a heavier fluid that can be used to keep the seals from leaking too soon. Don't know about the amsoil, though. Just don't have experience with it.
quick check for water, which is not always visible.
350 F hot plate, or throw away pan.
A drop of oil.
Does it crackle or sizzle?
It it does, you have more than 500 ppm water. (.05 %)
In general, 500 is not an issue, but it does mean your seals aren't perfect.
Of course, try your new oil too, that way you have a comparative baseline.
Remember, climate will affect it too, and seasons.
Disclaimer: 500 may be normal. Generally, I don't care about anything undt 1,000 ppm (0.1%) and I won't change an oil even then unless something else is evident)
Fork Oil 
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