by Kristian #562, 15 October 2001
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attempting any work in this FAQ.
Last Updated: 17 July 2006, by Winter #1935
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This FAQ also answers the question: I can pull my Clutch in, but it disengages slowly or is "sticky" when it disengages.
Here's a little recommendation for those of you who are removing the clutch cover for a Water Pump Replacement or for a clutch or Clutch Springs Replacement (see below under “Other Modifications/Repairs”). IF you have problems getting the cover off, it is possible that your clutch lever arm (PINION, Vertical Rod with a fine spline at top end that exits the casing and has a coarse "spline" at the bottom end) and your clutch release arm (horizontal rod like a RACK with teeth, that releases the clutch cover plate) are worn. These two, rack and pinion, which mate inside the LHS Engine (clutch) housing, on my bike were so badly worn and the splines bent to the point that the Pinion would not easily rotate off the rack. See Clutch Arm Close-up, Clutch arm. It should rotate OFF clockwise, i.e. when you are removing your cover. Anti-clockwise when it goes back on. I resorted to taking the gear shifting lever which fits exactly and has longer lever arm, on the fine Clutch spline and using that to rotate the pinion and thus lever off the casing. I only did this because mine was REALLY stuck, due to the bent splines on the rack. It is not NOT recommended but is a last resort.
I ended up replacing the rack, pinion and the bearing which sits inside the clutch pressure plate cover. It went on and came off (tested it) like a dream with the new parts. IF you get the thing off OK, I would recommend marking with a big marker, on top of the clutch Pinion, the third of the pinion spline that actually gets used to release the clutch. You will be able to see on the splines which are worn. On replacing the cover, you will then need to rotate the pinion BEFORE the rack mates with it, so that when the clutch engine cover is FULLY on, the pinion splines will operate on the rack only on the splines that have not already been used. This is possible because the pinion only rotates a third of turn when you operate the clutch. You will be able to see the location from your marked-up top of the Pinion. This assumes you've checked your rack and it too is OK, otherwise replace that too. btw They're not cheap parts to replace, I got a used Pinion, because there are still two thirds of that spline which are good. (But half of MY old one was shot). I suspect someone already had a play with the rack position on my bike, because the bearing race that holds the rack was NOT fully inside the clutch basket cover, but about halfway in. Perhaps this was from the factory, however it would allow the pinion splines to operate on a different part (the far end, closest the casing) of the Rack. I thus also replaced the bearing inside the clutch basket cover. (It was notchy) The Bearing Number is 6002. (Part 13 in the diagram). If you do replace this bearing, which should NEVER wear unless it is misaligned because it really doesn't get much load, be careful you properly heat the clutch basket plate it fits into AND you freeze the bearing or you will break the cast clutch basket plate, which looks like both a quite fragile and expensive item. My bearing just dropped in. Do NOT hammer this plate.
I also replaced the bearings that the Pinion fit into, the two smaller ones inside the left engine cover housing, Numbers HK1210 (Upper) and HK0808 (Lower-I think, sorry I lost the original). I only did this because I though they might have been affected by the mangled pinion and rack. I'm surprised my clutch worked at all and I must admit I had been having problems with it before my water pump failed. They are a ROYAL PITA to get out especially the lower one, because it is deep in a blind hole, and hard to get out unless you have a proper tool. As I couldn't see the need for an expensive bearing puller for this size of bearing in future, I couldn't bring myself to buy one so I ended up using (a) Heat and (b) a Hilti-Bolt. Those of you in Construction will know a Hilti Bolt is normally placed in a drilled hole in concrete and comprises a normal bolt with a Nut on the threaded end and in lieu of a hex head it has a tapered head. A shell goes on the outside of the bolt from the tapered head to the nut. The shell has a split part way along the head. On tightening the nut the tapered head expands the shell and grips the hole. I put this in my bearing to get a grip on the bearing, then gently tapped against the nut to drive out the bearing. Heat is important!
Lastly I got to wondering, Was the reason for these bent splines was the dodgy garage who changed the clutch before I got the bike or those stiffer clutch springs I put in ...? I did all my own work after that. Second one failed anyway, so must have been those springs.
BTW, another thing to watch. Before you remove the Clutch Engine cover, you have to remove the clutch cable connection to the aluminium clutch lever arm that sits on TOP of the clutch cover, on the fine spline of the Pinion. I thought I could do this by slackening off the cable as much as possible at the clutch handle on the handlebars, line up the slot on the knurled adjusting screw at the handlebars and release the cable until I had enough slack to release the lower end of the cable. I was wrong, there just wasn't enough slack. What I had to do was actually take the aluminium clutch actuator arm OFF the spline, (after slackening off the screw at the clutch lever on the handlebars) Reinstallation was in reverse order. If there is not enough slack to get the cable back into the slot at the lever end, I'd recommend DO NOT NOT NOT grab a pair of vice-grips and try to rotate the clutch lever to get the cable on. It is soft aluminium and may break. You CAN move it forward by hand to take up the slack in the thrust washers and may be able to get it on that way OR Put on the clutch handle end of the cable with a completely slack setting, and WITH the cable in the aluminium lever, place the whole lever and cable arrangement on the spline, rotating the arm with respect to the spline before tapping it on, to get the minimum slack. After everything is back on place, don't forget to adjust the rest of the slack at the clutch lever with the knurled screw. Line I don't say this from experience of a broken clutch lever but of prior experience with Cast Aluminium Dinky Toys. :-)
I am replacing my left engine cover due to play in the water punp shaft bushing and was wondering what the process is to install needle bearing in the new cover. I did read Kristians warning about removing them in the faq. I assume the cover will come naked without the pinion bearings being installed. Steve#417(in,us)
I also replaced the LHS Clutch Cover Gear Shifter and Clutch Shifter Seals while I was at it. They are Seal #s (Gear Shifter 12x28x7, Clutch Pinion 12x18x4.5). They didn't have a 12x8x4.5 for the Clutch Shifter (Pinion) so they gave me a 12x18x5 (But half a millimetre thicker works just fine). If it was one of the diameters it would be a problem. I packed all my seals, except the water pump seal facing the impeller (to avoid contaminating the cooling circuit), with grease, to protect the spring on the seal from corrosion and to provide further lubrication, even if it was only to install the cover. (Oil seals are pretty much self-lubricating, a thought I had when I was wondering the reasons for the water pump seal failure, apart from the soft shaft. Eureka, water is not as good a seal lubricant as oil. Seals are cheap, easily available from any bearing shop and you don't have to worry about them for a while. Actually the clutch and gear lever arm seals are both seals you COULD do without emptying out the oil, but it's messy and my philosophy with seals is "while I'm in there". Actually if you are VERY careful you can save the LHS Clutch/Engine Cover gasket too. Bearings are remarkably cheap too.
Refer both Part Number Bearing Schedule and Detailed Bearing Information & Resources for further information.
