Fork Oil Change - How to question
Ultimate HDF Member
Joined: Feb 2010
Posts: 8,039
Likes: 1,305
From: Jayhawk Country
Just did mine on my 11 RKC. I developed a leak by reusing the old bolt and crush washer. I had to do it again. Do yourself a favor and get the new bolts and crush washer at the dealer and replace them. Cheap insurance. I too had to use vise grips to remove the old bolt.
Extreme HDF Member
Joined: Sep 2005
Posts: 11,615
Likes: 50
From: Baton Rouge, LA
Hey all,
I have a 2012 Ultra Limited. I see it suggests not changing fork oil until 50K miles. Is that realistic? Also, in HD factory shop manual, it talks about taking the fork legs completely off to do the change. I thought you could just remove the lower drain bolts, remove the upper fork tube plug and just do it that way? But, the manual goes into the whole process of removing the fork legs from the bike, removing the fork spring and turning the fork upside down to drain the fluid out, ya-da ya-da.
Do you really have to go through all that? Any how-to posts would be greatly appreciated.
I have a 2012 Ultra Limited. I see it suggests not changing fork oil until 50K miles. Is that realistic? Also, in HD factory shop manual, it talks about taking the fork legs completely off to do the change. I thought you could just remove the lower drain bolts, remove the upper fork tube plug and just do it that way? But, the manual goes into the whole process of removing the fork legs from the bike, removing the fork spring and turning the fork upside down to drain the fluid out, ya-da ya-da.
Do you really have to go through all that? Any how-to posts would be greatly appreciated.
I'm not sure why HD changed the procedure from changing the oil every 12k, as per the procedure in the tutorial, to every 50k by disassembling the forks. All I know is that at 21k the oil was so foul-looking and malodorous that I would not have wanted to leave it in any longer. I'm now changing every 10k, as it only takes about an hour and costs very little.
I assume HD changed the maintenance interval to force owners into checking the bushings and other components inside the forks, which may wear over time. But until I hear or otherwise sense some indication that I need to tear them down, I'll continue with the 10k oil-change ritual. I put 100k on my old RK before tearing one shock apart to replace a leaky seal, and the bushings on that fork were still good, showing little wear.
I would heed KCFLHRC's advice about the crush washers on the top plug. I didn't replace mine for the first and second change and had no problems, but did for the third. Like he said it's good, cheap insurance.
Last edited by iclick; Jun 20, 2012 at 10:32 AM.
Cruiser
Joined: Mar 2011
Posts: 120
Likes: 1
From: SoCal
Yes it will
Extreme HDF Member
Joined: Sep 2005
Posts: 11,615
Likes: 50
From: Baton Rouge, LA
I've managed to get mine off without vice grips (so far) using a #3 Phillips bit and a ź"-drive ratchet. I doubt if a large Phillips screwdriver would work, as you can't get enough pressure on the screw. I replaced the Phillips screws with regular źx20 hex bolts on my old RK but haven't done that yet with my SG. I may do that next time around. That worked fine, but you must be very careful not to over-tighten them, as the bolt is steel going into short aluminum threads, which I suspect is why HD uses Phillips screws since it's hard to overtighten those.
Last edited by iclick; Jun 20, 2012 at 11:21 AM.
Road Captain
Joined: Jul 2005
Posts: 642
Likes: 3
From: Southern California
I've managed to get mine off without vice grips (so far) using a #3 Phillips bit and a ź"-drive ratchet. I doubt if a large Phillips screwdriver would work, as you can't get enough pressure on the screw. I replaced the Phillips screws with regular źx25 hex bolts on my old RK but haven't done that yet with my SG. I may do that next time around. That worked fine, but you must be very careful not to over-tighten them, as the bolt is steel going into short aluminum threads, which I suspect is why HD uses Phillips screws since it's hard to overtighten those.
I have a really nice inch pound dial torque wrench so no worries of over torquing.
Take care,
Dave
Last edited by Taildraggerdave; Jun 20, 2012 at 10:44 AM.
Ultimate HDF Member
Joined: Aug 2007
Posts: 9,486
Likes: 4
From: Hico, TX (once home to Billy the Kid)
Are the crush washers copper? If so you can re-anneal them with a small torch. That is if you forgot to go get new ones.
Heat till red - let cool = Like new.
Heat till red - let cool = Like new.
Ultimate HDF Member
Joined: Feb 2010
Posts: 8,039
Likes: 1,305
From: Jayhawk Country
Yes, they are copper.
Extreme HDF Member
Joined: Sep 2005
Posts: 11,615
Likes: 50
From: Baton Rouge, LA
That źx20 spec is based on memory and HD doesn't show the spec in the parts manual. Until someone verifies this it would be best to check the thread size of the stock screw first.
IIRC HD doesn't give a torque spec for that screw, but when I had the hex bolts on the old RK I would simply snug them down with very little elbow grease. I would guess I tightened them to about the same torque as you would an outer-primary or derby cover bolt, about 100 in./lb. I also put a chrome hex-bolt cap on them and they looked great.
Last edited by iclick; Jun 20, 2012 at 11:32 AM.
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