Clutch push rod seal and worm gear install w/ pics.

[TwoManyXS1Bs]

Been following this fellow for awhile.
From Japan:

 

[Vlad]

Wow!!! That long rod has almost no play! I just changed the bushing and seal on my SG and the short outer rod on mine has way more play than that. Looks like I'll have to change to the longer rod for sure!

 

[Vlad]

Just wanted to follow up on this specific piece of information:

If you do the seal replacement right I seriously doubt you will be at these again before the cases are split. I've been using sil-glyde on the clutch push rod seals with no problems with leaks on any that I've done, (8-10???) at least one has 5K miles on it so far.

Yes any lube should be fine. A nice warm seal wouldn't hurt either. I have sheared the little ridge off the outside of a seal or two while driving it in, but it made no difference, no leaks!

So, I was working on my brake calipers and after seeking out some info about re-assembling them, I have learned that grease and rubber are not friends!! Your recommendation of Sil-glyde is definitely specifically important as silicone based grease will not degrade the rubber. I don't think it would be okay to use any lube as other greases could break down the rubber over time which is especially bad for seals that chronically leak. Using a silicone grease like sil-glyde is a very important detail. So if someone's reading this thread and plans to use any type of grease on these seals, or perhaps on the outside of the pushrod itself, make sure it is a silicone based grease, something like sil-glyde, to ensure that the rubber will not degrade over time.

 

[MaxPete]

good info Vlad - thanks!

2M - that is a neat video - very useful.

Pete

 

[gggGary]

Vlad; brake parts rubber is a very special animal; it is brake fluid proof but hates greases. The rubber used in engine transmission shaft seals etc is designed to be in constant contract with petroleum products. Never hurts to be safe but I doubt any normal shop grease will bother those seals.

 

[MacMcMacmac]

I wonder if someone could machine a new worm gear with a slightly steeper pitch to get us those last few critical millimeters of travel to fully disengage the clutch.

 

[retiredgentleman]

I have found 2 things that improve the clutch operation:
First I modified the worm gear operating arm. Originally it measured 1.781". i drilled a new hole, so that it now measures 1.438". That is the distance from centre of the arm out to the hole that pulls on the arm.
Secondly, when I adjust the screw on the left side cover, I do not back off any amount at all. Same with the lever on the handlebars. I leave no free play when engine is cold.

I get more clutch plate separation this way.

 

[JayR]

Hey all. Finally got around to the push rod seal. Glad I bought two because my first attempt above was a fail - I pinched and sheared the seal edges. The reason is that I was a wuss with my first pass at deburring the edge. Could have use some lubrication too.

I removed more material on the 2nd attempt with my edging tool. Lean into it. Used the backside of a 17mm socket and some gentle taps with a rubber mallet - and the thumb press as well to seat it properly. I did not use any grease or yamabond, I just forgot really (I was supposed to be doing something else lol). So it went in as a dry fit.

 

[devildrums]

Clutch pushrod seal replacement how-to with pictures,


Remove the LH footpeg, shift lever. Before removing the cover' pop the small chrome cap off the clutch adjuster, there is a slot at the bottom, use a flat bade screw driver in the slot to pry the cap off, protect the aluminum cover to prevent scratching it. if you have an air wrench put a 12mm socket on it (13mm on 70-73) and loosen the nut with a quick burst of the air wrench. That nut is usually really snug. Remove the clutch cable from the ramp lever to free the cover, remove the chain from the sprocket. This would be a good time to clean the chain.

Check that the sprocket nut is tight, even with the folded washer the nut is often found loose, this is another common leak causer. A loose sprocket lets oil get past the output shaft seal.
Clean as much of the gooey crap off the case and cover inside as you can stand to do. I like paint thinner in a spritz bottle, paint and tooth brushes. A tub to catch the crap is a very good idea.
At least the area around the seal must be spotless. You don't want dirt in your engine.

Remove the push rod.
Use a screwdriver against the sprocket and pry the old seal out. This will take some effort and it will trash the old seal. Get the screw drive in far enough that it catches the metal washer inside the old seal, it will distort, bend and finally pry out. Remove the remains of the seal from the retention groove in the engine case.

View attachment 28137

Bevel the outside of the seal bore with a sharp hard tool, grinding a bevel on the side of an old screw driver would work fine to do this. I don't know where I got this carbide cutter but it works perfectly for this job.

View attachment 28139

Use a q-tip or three and get any aluminum chips out of the bore. The rod will be a loose fit in the bushing, it was loose when it was brand new, I don't worry about this, but new bushings are available from mikes if you feel the need.

Clean and polish your rod. It will have a groove in it where the old seal and dirt has worn into it. To smooth it, chuck it in a drill, round off any sharp edges with fine sand paper and then buff it, chrome cleaner on a rag will have it shiny smooth.

View attachment 28138

The bevel completed and ready for the seal.

View attachment 28140

I love syl glide and use it in lots of places, lube the seal, and with a q-tip put some in the bore too.

A 3/8 drive 17mm deep socket makes an excellent seal driver, the flat drive end should face towards the seal. Place the seal on the rod, more syl-glide, the flat side of the seal faces out.
Place the rod with the seal on it into the bushing. The end of the rod with a reduced diameter faces out. Use a hammer and lightly and evenly tap around and around the socket, keep the seal straight and even as it goes in, until it is flush to the case.


View attachment 28141

New seal in place.

View attachment 28142

Replace the chain.

Note the correct orientation of the ramp lever then remove, clean, and lube the ramp.

View attachment 28143


Check that the nylon isn't cracked. Loosen the nut on the adjuster screw, this is usually really tight, placing the ramp in a vice helps. See above, it's best loosen the nut BEFORE you remove the side cover or after you have reinstalled it. there is no good way to hold the worm to loosen the nut once it's off the cover. the round stamped metal seal holder is soft and very easily bent.



Check that the ball bearing is still in the ramp gear.

Missing

View attachment 28144



The bearing is 5/16" or #10 available at any hardware store. If needed you can restamp the stake marks so the bearing stays put, the rod still needs to fit past them. A dab of grease will keep the ball in place also. Some aftermarket worm gear assemblies are "over staked". Check that the rod fits past the stakes and touches the ball!

View attachment 28147

ball in place and restaked.

Comparison of early and late arms, the longer, early arm makes for an easier pull but it's fussier about adjustment and clutch wear. The late arm could be drilled for the early attach point.

View attachment 28145

View attachment 28148

Use lots of grease before reassembling, this is a nasty environment, you are trying to keep dirt from getting into the ramps.

View attachment 28146

Reinstall, adjust and test ride!

I may have missed it somewhere, but what kind of syl glide lube do you use? I have seen many different types.

 

[gggGary]

Whatever they have on the shelf at NAPA is what I've been using.

 

[DogBunny]

The proper spelling is Sil Glyde, and I'm pretty sure that the same stuff is inside all of the different packaging.