Fork Oil Change
My 2013 Slim is overdue for the fork oil to be changed. I need to know the capacity for each leg and also what weight fork oil I need. I'm asking for the specific weight as I will be using aftermarket oil not Harley Davidson oil which probably uses their own weight code. TIA.
On the 2001-2006 it is 13 oz or 384 ml for dry forks of 10wt.
But if you are not taking the legs apart and are only taking the top bolt off and the drain screw and pumping the forks to drain you will not get it all out. The safest way is measure what comes out and replace with the same amount. if you over fill because you add the full amount and your forks were not empty you risk blowing the fork seals.
Ive replaced all of my HDs (XL1200r, RKC, FLSTFI, FLTRX) fork oil with SE Fork oil I believe it is 15 or 20 wt and progressive springs (on the fatboy Ive used monotubes and now springs and race tech emulators). Also in my experience unless you are doing something else -springs- race tech gold valve emulators - monotubes etc. changing the oil alone wont make any difference in performance.
But if you are not taking the legs apart and are only taking the top bolt off and the drain screw and pumping the forks to drain you will not get it all out. The safest way is measure what comes out and replace with the same amount. if you over fill because you add the full amount and your forks were not empty you risk blowing the fork seals.
Ive replaced all of my HDs (XL1200r, RKC, FLSTFI, FLTRX) fork oil with SE Fork oil I believe it is 15 or 20 wt and progressive springs (on the fatboy Ive used monotubes and now springs and race tech emulators). Also in my experience unless you are doing something else -springs- race tech gold valve emulators - monotubes etc. changing the oil alone wont make any difference in performance.
I'm OK with the forks as is, I doubt if the fork oil had been changed on this bike since it was new so it it is probably past due. After 7 years that oil has to be pretty black and dirty.
You probably ought to buy the Factory Service manual if you're doing your own wrenching.
Its hands down the best vs any of the other versions...
When I changed mine, (also added Intiminators) I got two Harley fork rebuild kits
and used Amsoil #10 Shock Therapy.
To set the correct oil height, I used the MotionPro fork oil tool.
https://www.motionpro.com/product/08-0121
hth,
T.
Its hands down the best vs any of the other versions...
When I changed mine, (also added Intiminators) I got two Harley fork rebuild kits
and used Amsoil #10 Shock Therapy.
To set the correct oil height, I used the MotionPro fork oil tool.
https://www.motionpro.com/product/08-0121
hth,
T.
Last edited by WKNDS; Jan 17, 2020 at 09:19 AM.
I have stacks of shop manuals for all sorts of bikes including twin cam Harley's but at the moment none for a 13 Slim. I really hate to go out and buy one just for simple jobs like fork oil or brake pads, jobs I've done many times over when all I need is oil weight and capacity. Eventually the time will come when I pick one up when someone has one used for sale at a good price.
So has anyone came up with the correct amount to put in these babies? I can’t find it anywhere. Harley doesn’t help either.. atleast the dealership near me!
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Yes, you are correct and I don’t usually wrench on everything, however they couldn’t get it in the shop within a reasonable timeframe. I am also too cheap to spend the 200.00 on the manual for just for one job. I just had the sliders powdercoated after 9 years of wanting it done.






