Changing Fork Oil on a '08 Heritage Softail

Discussion in 'Softail Models' started by Bikergeek, Aug 15, 2012.

  1. Bikergeek

    Bikergeek Active Member

    I am looking for simple but clear instructions on changing the fork oil on my '08 Heritage Softail. I see so many different methods and none of them refer to my specific model. Someone here must have the "best" method to perform this service on my bike.

    I have a bike lift and hopefully all the tools necessary.
  2. 89stroker

    89stroker Active Member

    Do you have a service manual for the bike? The process would be spelled out in the service manual.

    Softails are generally quite easy to change oil in the forks.
    Lift the bike up, locate the drain screw on the backside of the fork near the bottom of the fork. Remove the screw, of course have a drain pan under to catch the oil. To remove the screw, you need a well fitting bit (any ones I have ever done were phillips head) and I always use an impact driver on the drain screw. If you don't have an impact the bit must fit nice an tight or you will damage the head.
    Next remove the large top nut on the very top of the fork, I can't remember the size off the top of my head right now. Be warned that when you take this nut off you will introduce air into the fork so the oil will generally shoot out of the drain hole in the bottom. Knowing this, I use a drain pan that is large enough so the oil doesn't spill all over the place. The top nut on the softail is not under spring pressure so you don't have to worry about a projectile flying past your head when you turn the last thread. Not knowing what handlebars you have on your bike, you may have to remove them to be able to get the top nuts all the way out, just lay a towel on the tank and remove them from the risers and let them lay on the tank.
    Once all oil has drained, check over the sealing washers on the drain screws, service manual will tell you to replace them but I have always used the old washers unless damaged. I use a small amount of thread sealant on the treads and re-install. This is where a manual is good as it would give you the torque spec on these drain scerws, they are small and stripping out the drain hole would be quite easy if over torqued, I only have a manual for a '99 at the moment so I am not sure of my spec is right for your '08.
    Once drain screws are back in and torqued, pour a measured amount of fork oil in through the top, again a service manual gives you the exact amount of oil for each fork. I use a funnel with a piece of tubing on it to get the oil in the forks, especially when the bars are on.
    Re-install top nut and torque to spec.

    Repeat steps for the other fork, reinstall bars (if you had to remove) and your good to ride.

    Hope this helps:s
  3. Bikergeek

    Bikergeek Active Member

    Yes, I have a Clymer service manual for my model . It has the specs;

    Fork oil Type: H-D Type E
    Fork oil quantity: 13.4 oz. each side

    Torque values:
    Drain Plug: 52-78 in. lb.
    Fork Cap Bolt: 60-70 ft. lb.


    Your instructions are good except; I would remove the fork cap first before removal of the fork tube drain plug (as per the manual's instructions) because I would rather be down there by drain hole with drain pan in hand ready to catch the oil as it pours out. Interesting though, the Clymer manual suggests applying front brakes and press down on forks several times to help "pump" out the oil. I suppose this gets it all out.

    I wanted member's opinions on how they do their oil change to see if there are easier methods. Apparently this bike is rather easy to do. Thanks.
  4. tourbox

    tourbox Senior Member

    One other thing I do if removing the handle bars is to use a black sharpie pen to mark the handle bars to the risers.You can use tape to mark on or just the mark the riser/handle bars with a straight line to realign where you had them,if you were happy with their original placement.
  5. softailhog

    softailhog Active Member

    You might want to consider switching to a heavier oil when you make the change. The type E oil is very light. HD has a couple of heavier Screaming Eagle oils that are heavier and I have found they work much better in my Heritage. The forks don't bottom out and the handling is much better, especially in cornering. I believe the type E is a 5 wt. oil and the SE oils are 10 wt. and 15 wt. if I remember correctly. I personally like the 15 wt. Several others have tried other brands with great success. Unfortunately HD doesn't print the viscosity anywhere on the product, I am going by what others have found and personal experience. Just my opinion.....
  6. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    I am right now in a project to change out the forks on my '03 UC to get rid of the cartridge on the left side, and end up with the '06 and above configuration. So the procedure that 89Stroker descibes above is the one for my bike after the change. This is already the procedure for my little bike ('91 Dyna). I would add the step of stroking the forks a few times once the oil stops flowing out of the drain holes.

    Additionally, I would measure the amount of oil out of each side, and put that amount back in if you know that the levels were right and even to start with. The only way to know that is to have followed a procedure to measure the air gap above the oil and to have set it per the HD spec, or as adjusted to suit. What I did to determine that for my new forks is the following:

    • With the forks off the bike, drain the oil out by removing the spring keeper nut, removing the spring and invert the fork into a container
    • Pump the tube a few times to get the rest out
    • Turn the fork upright and put anything back that came out except for the spring
    • Remove the drain plug and drain out all that will come out
    • Pump the tube a few times to get the rest out and replace the drain plug
    • Collapse the tube as far as possible
    • Measure the tube
    • Extend the tube as far as possible
    • Measure the tube
    • Calculate the difference and write that down (mine was 3.500")
    • Measure the spring keeper nut from the shoulder to the top and write that down (mine was 1.125")
    • Collapse the tube all the way
    • Add the recommended amount of shock oil (mine was 350ml)
    • Remove the excess oil to establish the specified air gap (mine was 4.88" or 4 7/8")
    • Insert the spring in the tube (dense end down)
    • Measure the air gap with the spring in and tube all the way down and write that down (mine was 2.125")
    • Add up the figures you wrote down - this is now the air gap that you will want with the fork fully assembled (mine was 6.750")
    • Assemble the fork and check the air gap
    • Mount based on Factory Service Manual procedure
  7. 89stroker

    89stroker Active Member

    I have never gotten much oil othere than a few drips by pumping the forks up and down, that's why I didnt include it. Now if you had a touring rig then it is a different story for changing oil.

    Great tip!

    I did bump up to a #10wt in my softail and it made a great improvement.

    Very detailed! I do measure as well what comes out when I drain the forks 'cause I am very picky with my bikes.
  8. Bikergeek

    Bikergeek Active Member

    I did it...I changed the fork oil in my garage. I went to the H-D dealer and asked about the oil. They only had the Screamin' Eagle fork oil on the shelf. When I asked about the regular H-D oil the service guy told me that is the only oil they use when servicing bikes so I bought two pints @ 5.95 each.

    I bought a six piece jumbo combo wrench set from Harbor Freight that included the 1 3/8" box wrench needed to remove the top fork cap. That was very easy to remove (proper tools). The lower drain plugs were a bit more difficult since Harley used phillip head screws. Why? Why not use hex head type screws? Safer and easier to remove I would think. So I want to look around and see if I can replace the stock drain screws with a hex head. Anybody do this? And if so, what thread is used?

    The old oil was really gross; very dirty and discolored. I measured the amount of drained oil in each fork to match my refill amount. I got out 13 oz. The book called for 13.4 oz. so I tried to keep it close to that figure if not a bit less. Oh yeah, the H-D service guy told me that the amount of oil "must" be exact to the specs. Huh? "Exact". Yeah, right!!

    Took bike for a road test and it road very nice around town. On the open road I felt the bike was a bit stiff and felt shakey like the bike was feeling every little road defect. I guess over time it will relax. Otherwise my refill was a success and worthwhile doing.
  9. yellotang

    yellotang Member

    I am of the camp that if you go changing out the oil, one should go ahead and change out the fork seals as well.
  10. Alter

    Alter Member

    I've got 2 pints of fork oil sitting on the shelf waiting to be put into my 04 heritage. I just haven't had the time over the last few weeks to neither ride nor maintance my bike.
    The tips are a great read and will help me on my virgin flight in changing my fork oil. It seems not to be difficult as I just got to find the time. I changed my brake fluid and if the brake fluid color is any indication of what the fork oil is going to look like then I'm looking at some well spent time in changing my fork oil.
    Here is a couple pics of the pretty purple Dot5 brake fluid I pulled out of my heritage, I never thought what heat and friction does to brake fluid untill I refreshed my brake system and saw this.