Thought I'd do a quick write up on how to disassemble the forks on a late model CL77 since the manuals I've seen have nothing about these forks.
Best reference is the parts diagram.
You can leave the forks in the triple trees if you want. This makes seal replacement easier.
1. Remove the drain plug in the lower part of the aluminum slider and drain the oil. Pump the slider to make sure you got as much as possible out of the slider. Saves making a mess, later.
2. Slide the rubber boot up and off the bottom aluminum slider. I used a small plastic clamp with rubber pads clamped to the fork tube to hold the boot out of my way when I worked.
3. There is a threaded ring with two holes on top of the aluminum slider. I tapped mine out with a small steel punch. The correct method is to use a 2 pin spanner wrench, which I later made for reassembly and future disassembly purposes. The ring is about 1/4 inch thick.
4. With the ring removed, you have two methods for removing the slider. One is to slide the slider up and then pull it down sharply to drive the seal out of the slider. Or, using a small piece of hardwood and a hammer, tap on the edge of the slider until it you see the seal coming up (my method). At this point, unless you have a lot of corrosion in there, you can now just use the slider as described above to tap the seal out the rest of the way. Hang on to the slider because it will now be free. Slide it down the leg and off. The fork spring will follow right behing it as it slides out of the upper fork tube (pipe).
5. Now, with a pencil and your parts diagram handy, look at the rings that hold all the valve parts in place on the upper steel leg. Each retaining ring is a little different and writing down which one goes where will help in the reassembly process. I suggest you right it right on the parts diagram with a little line pointing to each retaining ring.
Here is the order, starting at the bottom of the fork leg.
Bottom - Flat, wide width ring
Second - round thin ring
Third - Flat narrow width ring
Fourth - Round thick ring.
Note that the second ring, the thin round one, is not visible until you remove the piston (sleeve).
6. To disassemble, remove the bottom ring first, and slide off the piston. Note the position of the counterbore inside the piston bore. It faced upwards. Note this on the parts diagram as well.
7. Now remove the second round thin ring. This will allow the valve (narrow sleeve/ring) to be removed. Note the position of the chamfer on the ID of one end of this ring. The chamfer faces down when the ring is installed. Note this on the parts diagram.
8. Remove the third ring, which is the narrow flat ring and the fourth ring, the round thick ring, which will allow you to now remove the aluminum fork pipe guide.
9. Between the bottom of the flange on the fork pipe guide and the counterbore in the top of the fork slider (where the fork seal fits) is an o-ring that seals that area. When you removed the slider, the o-ring may have stuck to the slider or it could have remained on the aluminum fork pipe guide. Make sure you find that o-ring.
10. You can now slide the old seal and threaded oil seal retaining ring down the steel fork tube. It will stick in the various grooves on the way down.
11. You should clean out the fork tube before you reassemble the fork. I used a shotgun cleaning rod with a simple jag on the end and a big chunk of cotton rag. First I soaked it with mineral spirits and shoved it up the tube and swabbed it out. Do this until it comes out clean. You might have to change your swab a few times depending on the conditions inside the tube. Then repeat with a dry swab. Do this before you do any other work, so any remaining min spirits has time to evaporate.
12. Clean all the parts in mineral spirits or your favorite parts cleaner. Don't forget to remove the fork boot and clean them inside and out at this time. There is no need to remove the bolt from the bottom of the lower slider to remove the damper tube inside. It is not even shown on the parts diagram. It however, your slider is a gooey mess, you might want to in order to properly clean it. If you do this, you need to do a couple of things upon reassembly.
a. Anneal the copper sealing washer under the bolt head by heating with a torch until it is red and quenching in water. I then light sand each side until it is flat using 360 grit wet/dry paper and a plate a glass. Sand in a figure 8 direction to keep it flat and parallel. Do both sides.
b. When you reassemble the damper tube to the slider, I suggest you use an impact gun and just give it a short burst. Rat-a-tat-tat is all you need. There should be no need to hold the tube. Friction between the mating aluminum surfaces should hold it still once the bolt is initially snug.
13. Inspect the threaded seal retaining ring for corrosion. It is a steel ring with a cadmium plating. Mine had some areas of severe rust. I ended up putting it in phos acid to remove all the rust from the pits. Unfortunately, it also removes any remaining plating, but I knew that going in. We will protect it a couple of ways on reassembly. First, once clean, paint it with your favorite aluminum paint. I use Duplicolor caliper paint. It is very durable and dries fast. I use a hair dryer to quickly dry it. The second protection step comes in the reassembly process.
14. With everything clean and dry, you can now begin the assembly process. Coat each piece with fork oil or light engine oil before you install it. Make sure the area is clean so you don't get any dirt or grit on the oily parts. Also put a light coat of oil on the fork tube all the way up the chrome section.
15. I put a light coat of outboard motor waterproof grease on the upper portion of the fork tubes, where they are covered by the boots. I'm anal about corrosion protection. Just put a light smear on with your hand. You can get this grease at any marine supply store. Mercury is one of the brands.
16. Slide the fork boot on and slip over the headlight bracket tube. Put your clamp (clean pads) back in place to hold the boot collapsed and out of your way.
17. Lubricate fork seal with fork oil. First slide the threaded retaining ring up the tube followed by the fork seal. Be very careful and patient as you work it past the grooves on the fork tube. Once past the grooves, the seal will stay in place on the tube and hole the ring up there as well.
18. Now starting with the parts in reverse order, install the fork pipe guide with o-ring, two retaining rings, the valve, another retaining ring, the piston and the final retaining ring. Make sure to orient the chamfer in the valve and the counterbore in the piston in the correct positions per the notes you made on your parts diagram.
19. Now coat the entire seal retaining ring and the outer diameter of the seal with anti-seize. This will make the next seal change that much easier and prevent corrosion. Lightly oil the inside of the lower aluminum slider, insert the fork spring into the fork tube and then slide the slider up the tube. While holding, you should be able to press the seal into the top of the slider. It must be straight or it will bind. Go slow and just pull the slider down if it binds and start again. Once the seal is in, you can now push it down further with the threaded seal ring until the threads engage. Make sure the ring is straight and square to the slider and then with your fingers start the ring into the threads. A turn or two and you can let go. Now take a short breather, let your arms rest, and then go back, push up on the slider and screw the seal reatining ring home. I made a wrech from 1/4 alum plate on my bandsaw and used two roll pins to engage the holes in the ring. If you did not do this, then with a small punch, just tap the ring tight. No need to go gorilla here. You don't want to distort the holes or make it impossible to remove the ring in the future. If you make a wrench, then put a the wooden handle of a hammer between the studs for the axel clamp in the bottom of the slider to keep it from turning and snug the ring with your wrench.
20. Now the last step in protecting your seal retaining ring from corrosion. Using the same outboard motor waterproof grease, smear a liberal coating on top of that ring. Push it down into the wrench holes as well. Every so often, maybe at the beggining and end of each riding season, pull up the boots and clean the area and put a new smear of grease on those rings.
21. Now just slide the boot over the top of the slider and you are good to go.
I hope you found this helpful.
regards,
Rob
1967 CL77 Front Fork Disassmbly Guide
Re: 1967 CL77 Front Fork Disassmbly GuideHow ya get the front high enough for he slider to clear the tube?. ....lm
Good question, LM. I assumed everyone has their own way to jack/support the bike. But it can be tricky due to the balance points of the bike.
First, I use a lift table from Harbor Freight. Too old to bend over and still smile all day. I use a racing stand on the back swingarm to give the bike a solid and stable base. I put a strap on both sides from the frame to a tie downs on the lift. Straps are vital for this. I also put two straps on the handlebars down to tiedowns on the lift so I end up with 4 points (straps plus another 3 (jack and racing stand) as the support for the bike. The front is the tricky part to lift because the CG of the bike is just about anywhere under the engine. By that I mean if you jack anywhere under the crankcase, you end up lifting the entire bike. So, I cut a small piece of 2x4 that slides up under the curved yoke at the front of the frame where the lower portion of the frame meets the front downtube. Of course, skid plate is removed. The block is cut at an angle so that when it lies flat against the front of the crankcase, the bottom of the block is parallel to the surface of the lift table to provide a horizontal jacking surface for the jack. I suppose you could use the center stand instead of the racing stand, but my bike had a 4.00 rear tire (to be changed back to a 3.50) which made the stand too short to use for this. Plus, the stand could fold up on you, if you ever rocked the bike fore and aft and that would result in major heartburn. Attached is a sketch showing both side and front views of how the block is positioned. Block is shown outside the frame tube just to provide a view of how the wood block is positioned. I've since removed the racing stand so I could work on the swing arm. I jacked up the front of the bike with the jack as shown until I could put a stack of wood blocking under the engine, towards the back of the bike. I then lowered the front back down and the bike came off the racing stand and onto the wood blocks so I could then remove the stand. This is how I was able to remove the swingarm. Block is shown in the same attached sketch should somebody want to do this. A note regarding jacks. I use scissor jacks with a wide plate welded to the base for added stability. I would not use a scissor jack without such a baseplate because it is too easy for the bike to fall off the jack. regards, Rob
fork pistonsI am rebuilding my front forks, 67 cl77 and am having trouble getting off the fork pistons. This writeup says to slide the pistons off after removing the retaining ring. Mine seem quite stuck. Any advice would be appreciated. Thanks
front forksI know this thread is old but I just used it to take apart the front fork seals on my CL77. The attention to detail is perfect. The only things missing are photographs. When I put it back together I will see if I can add some photographs.
Thank you for your time and effort.
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