KX Riders
Maintenance & Technical => KX500 Original => Topic started by: kawdude on February 22, 2004, 04:14:37 AM
-
How do replace the oil seal on the rear shock. I have the instructions that were post on changing the oil but I need to know how to change the seal. How does the seal come out of the plunger thingy (technical term)??? I'm also making the assumption that the seal is inside the thingy and not at the end. The piece on the end looks more like a crud scraper.
-
DOH! I got it. Whole piece has to be replaced...
-
Kawadude,
I found a pdf on how to get the seal off. It was on motoproffessor.com. They grind off the welds that hold thepiston on, uncrew the piston, replace the seal and locktite it together. If you cant find it send me a note and I can email it to you. Cam.
-
That would be an interesting read. What's the website. I can't get motoproffessor.com to go anywhere.
-
Mine was seeping oil also and only had about 45ps nitrogen pressure left in it. White Brothers has the complete seal head for around $38.00(considerably cheaper than Kawasaki's $90+). That is where I got mine. I figured since I had it torn down that far I am going to try the Race Tech Gold Shock Valve(backordered) and set it up myself.
John
-
That is a lot cheaper!!! I'm there.
-
Here is a word of caution.
As you look at the end of the shock shaft, you will notice that the end of the shaft has been riveted against the the nut. In order to get the nut off, you have to ruin most of the nut by grinding the nut and end of the shaft at a 45 degree angle. After you grind a little, try and gently turn the nut. If there is still resistance, grind a little more and try the nut again and again until you have removed just enough material to get the nut to thread off the shaft. You will also need to have puchased a new nut before you begin, as the old nut will be unusable. If you remove all of the riveted section of the shaft, you have ruined the shaft, so be very careful. If you have access to a lathe, you will be able to maching the edges of the riveted section without any risk, but most folks don't have access to a lathe. Remember to locktite the nut on installation.
You may also be able to remove the shaft from the bottom fork by unscrewing the shaft (only after you disassemble the shock). The seal would then just slide right off and the new one on. However, I have never installed a seal by removing the shaft, so can't say for sure, but believe it will work. All of my shocks are revalved, so the shaft has already been modified for easy removal.
You also want to avoid damaging the seal when you slide it over the shaft past the threads, so wrap the threads with tape before you install the new seal, and lube with oil. This is the same process as when you install a new fork seal over the lower leg, but in that installation I use the corner of a sandwich bag to ensure the seal is not damaged.
As you can tell, there is some risk in this process, so be very careful. I have used the White Brothers seals before, and they work just great for a lot less money. While your in the shock, check the bladder and make sure it is not damaged. Once you install the seal, follow my old post on shock rebuilding and you should be in good shape.
One additional note. If you grind off the nut, it is critical that the shim stack on the shock valve be kept in order. Once the nut is off, push a philips screwdriver into the shaft hole a little, and slide the shims and valve onto the screwdriver all the way to the handle. Place a zipty on the screwdriver shaft to keep the shims from falling off. Once the seal is installed, put the scredriver back into the shaft hole and push everything back in place. Use spray carb cleaner to flush the shims and valve once on the shaft in order to remove an debrise. Blow down with air to help the cleaner flash, and continue with the installation.
Good Luck, and let us know if you get stuck.
Rick
-
Thanks for the caution. I took it apart and discovered that the shocks been apart before. The nut was already ground down and reused. Thanks for pointing out that I should inspect the bladder. It has a nice 1/2 tear in it. I have ordered the WB seal and bladder but the seal is on bo. Anyone know who else sells the seal head?
-
Kawasaki.... $$$, but better than not riding. Might also check with Race Tech.
-
You can get the seal head from Race Tech for 38 dollars plus shipping.
-
Thanks! I use them instead. Their site lists 3 sizes.
SHK KYB SEAL HEAD 40x14x22mm
SHK KYB SEAL HEAD 44x14x23.5mm
SHK KYB SEAL HEAD 46x16x24mm
Anyone know what size I need? I think it's the 16, but not sure.
-
Give them a call and tell them the year of your machine. I'll bet they can figure it out just with that information. If not, they can tell you how to measure your current seal.
Good luck
Rick