GSX-R 750 Pictures of how I changed the fork seals on my 1985 1986 1987 Suzuki GSX-R750 motorcycle.

I have leaky forks. Maybe I should see a doctor, but I decided to ignore that and work on my bike instead.

This is going to be a long page. Lots of pictures. Let's get started.

But first, lets pay some bills:

  1. Took off plastics - pics of that in "Fairings" in menu on left.

  2. I supported one side with wood blocks.
    got wood

  3. I jacked up the other side
    jacked up

  4. The day before, I put WD-40 on everything:
    • Brake bolts
    • Fender support
    • Axle Nut
    • Pinch Bolt
    • Triple Clamps, upper and lower
    • Handle bar hex bolts and hidden screws underneath
    • PDF dapmer bolts too


  5. The brake bolts were frozen yesterday, today they came off easy.
    brake bolts

  6. The fender support bolts were beat up where they had been treated rough by the wrong size allen wrench or an improperly seated one. So I was careful and no strips or losses.

  7. This is the exploded diagram of the GSXR front axle. Note that number 2, the aluminum spacer, is shown here backwards. The thick rim of the spacer has to go on the inside of the axle.
    front axle diagram

  8. Big wrench
    Big Wrench

  9. Breaker bar
    Breaker bar

  10. Speedometer gear. Greasy.
    Speedometer gear

  11. Upper triple clamp bolt. Socket extension and long socket used for leverage.
    triple clamp

  12. Lower triple clamp bolt. Same thing.
    triple clamp

  13. Handlebar bolt. No leverage necessary.
    Handlebar bolt

  14. I marked the alignment of the fork, triple clamp, and handlebars. This helped during reinstallation. There is a screw under the handlebar that screws into the upper triple clamp, and will only let it line up in one spot. I had to skip this screw and use my alignment marks on one side to keep the handlebar from hitting the fairing at full lock. Something must be bent somewhere. Dammit. Time to get out the measuring tape and steel ruler and go to town.
    alignment marks

  15. When all that is loose, the forks just fall out. I almost dropped the first one. I put the brakes up on a box to keep the weight off of the brake lines.

  16. I laid out the forks on the workbench. Shiny.

  17. I almost forgot the pinch bolt and that spacer from the right fork.

  18. With those out of the way, I could put a big allen into the bottom of the fork and grab the damping rod. With the springs still compressed, I was able to loosen one of them.
    loosen damper rod

  19. The other damper rod just spun and I could not loosen the bolt. So I used my impact wrench.

    wrench + impact = impact wrench.
    impact wrench

  20. I was worried the caps would be on too tight and I would have to reinstall them in the triple tree to get them off. Luckily I was the one who put them on last, and they were just snug. Easy to get off.

  21. So now the springs come out, and I flip the forks to drain them. While they are here, I measure the tube diameter so I can try to get some kind of seal driver for later. The tubes have a 41mm Outer Diameter.

    If I were just changing the oil, I could stop here. I could even have skipped loosening the damping rod. But I am here to change the oil seals. So I must press on.
    drain oil

  22. Pressing on, I remove the dust seals.
    dust seals

  23. Then this wire snap ring on the inside of the outer fork tube.
    snap ring

  24. With that snapring popped loose with that same small screwdriver, this big washer is let loose.
    snapring and washer

  25. As long as the damper rod bolt is COMPLETELY removed, not just loose, a few mild yanks pulls the inner fork tube out of the outer fork tube. Along with it come the fork oil seal, another washer, and the teflon coated slide metal bushings.
    forks apart

  26. I turned over the inner fork tube, and down fell the damping rod and spring.
    Damping rod and spring

  27. To do a good cleaning, I removed the PDF Positive Damping Fork oil damper units.

  28. Two little o-rings seal the oil damper to the fork. Sorry I didn't take a better shot of it, but turning the adjuster on the top moves a plunger which makes the lower opening bigger or smaller, controlling oil flow through the unit. I don't understand how it works.

  29. This little piece of aluminum was stuck in the tube. A small allen through the damper hole popped it out easily.
    popped out

  30. Here are all the parts. Left to right we have the:
    • dust seal
    • washer
    • internal wire snap ring
    • oil seal
    • washer
    • slide metal bushing
    • some kind of aluminum thing from the bottom of the tube.
    • a bunch of washers and wave washers.

    laundry list

  31. Oh, and here are the spring preload and junk from the top of the springs. Follow the Fork_Oil link in the menu on the left for more info on these.

  32. There's the bottom of the inner fork tube, scarred from rubbing on the bushing for the last 30k miles.
    outside of inner fork tube

  33. There's the inside of the bottom of the inner fork tube. That holds in the damper rod and spring.
    under inside of inner fork tube

  34. There's the inside of the outer fork tube.
    inside of outer fork tube

  35. Well, now that everything is disassembled, I gave it a good cleaning. And I laid out the parts and did an inventory. In one fork there were two little washers under the damper rod. In the other fork tube there were four and a half. This is a problem. There should be a wave washer, then a flat washer, then another wave washer. All these on top of that little piece of aluminum on the far right. The copper washer goes outside the fork, underneath, between the fork and the damper rod bolt. I need to go to the hardware store again, so I will take a break, and continue this with the reassembly on the next page.
    long confusing sentences

  36. Next I sold out to make 02ยข so I can fulfill my lifelong dream of owning a 1986 944 with blown head gaskets.

    But no minivans!

  37. Then I finished my beer.

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Disclaimer: The technical information in these documents is provided without any warranty whatsoever and at no cost.   All information is in general terms and is not meant to apply to your particular situation, be current at the time you read it, or even be correct in the first place.   Improperly maintained vehicles can lead to serious injury, death, or unavoidable accidents. The author is not responsible for any errors on this site, and does not make any claim at all about the validity, safety, or veracity of the information contained on this website. Any work you choose to do or not to do on your vehicle is done at your own risk. The information on this site is not intended to serve as a replacement for professional advice, professional workmanship, dealer service, union labor, or psychological counseling.   The author disclaims any and all liability directly or indirectly arising from the application or use of any information or idea contained on this or any other web site.   By opening this page, you agree to never sue anyone ever or allow anyone to be sued on your behalf.   The appropriate professional should be consulted regarding your specific condition. does not take responsibility for the information posted on other sites to which it links.

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