Finally got to rebuild my DR650 forks, they have about 13,000 miles on them. The seals were worn and leaking, and the fork tubes had significant play in them. After installing the new bushes, all the play was gone, and the fork cycled smoothly. Here are the parts involved:
All Balls fork seal kit and fork bushing kit, $55 from E-bay. The All Balls seals have a double seal lip, and the kit is quite complete: upper/lower bushes, seals and dust seals, brass washer, fork cap o-ring, and seal retaining clip.
Here are the new bushings in front, the old bushings in back.
This is the fork disassembled with all the parts layed out:
Here is the worst offender, the plastic cap on the end of the damper. It is critical to assemble the fork properly to not have the fork "lock down."
To start the rebuild, we made a very high-tech special tool, to hold the damper assy while loosening the allen at the bottom of the fork leg:
While you can make a special tool using a 1 inch nut and some smaller nuts, we got inventive!
So, take the fork apart by pulling the fork tube out. The seals and upper/lower bushes will come right out. Then, clean the fork legs out, there was a lot of grit and fine particles in the oil. I used solvent and compressed air to clean the forks out.
Then, put the new lower bush on the fork tube:
Lather up the fork tube, damper and fork leg with clean fork oil. HERE IS THE MOST IMPORTANT PART: when slipping the damper back into the fork leg, make sure the plastic spacer on the end of the damper protrudes from the fork tube.
Then, slide the fork tube in, and just snug the allen bolt tight on the damper. Cycle the fork tube up and down to make sure its free, and not bound up. Insert "special tool" and tighten allen bolt. We just tightened by feel.
Next, install the upper fork bush, using the old bush and a drift to tap it in place. Next, the large steel washer on top of the bush, the fork seal, and the dust seal. Lastly, the clip to hold everything in place.
Gently tapping the dust seal in. Make sure all the seals completely seat in the fork tube.
Lastly, add 10wt fork oil, should be filled to 6.5 inches from the top with fork springs removed. Make sure to cycle the oil through the fork several times to ensure the oil is flowing through the damper and there are no air bubbles. Then install springs, preload spacer, and top cap.
Now the forks are ready for a big ride this Spring through New Mexico!
IMO it is always a good idea to replace fork bushings if the fork seals are actually leaking from wear and not just dirt trapped under them. The looser the bushings become the less amount of time you'll get out of your new seals before they start puking again.
