CLUTCHES 101-Part 1: the 400/550/600s with pics

Well, as long promised, here we go--

CLUTCHES 101: Part 1, the 550 and its brethren:

First item of business: a quick note on the differences between the 400, 550 and 600s and their world-market cousins. They seem to differ a bit in the number and placement of "clutch boss springs" which is covered in detail here: http://xjbikes.com/Forums/viewtopic/t=22927.html so we won't repeat that discussion here.

Suffice to say, this article was done with a North American-market XJ550. If you're working on a Euro or world market bike, or an XJ400/4 or 600, yours will be slightly different.

ALSO NOTE: MOST of what is presented here also applies to the bigger bikes. Their clutches are actually easier, because they do not have the "tabbed" plain plates or clutch boss springs to worry about.

So let's get on with it.

We'll start with the exploded view, annotated as discussed above:




PUT THE BIKE ON THE SIDESTAND, put a pan under it, and let's get the cover off. Putting it on the sidestand means you'll lose little or no oil in the process. On the 550, you'll need to remove the brake pedal and RH rider footpeg to pull the cover.

PRECAUTIONARY NOTE: Any crud or other debris you might dislodge that falls into the bottom of the clutch cavity will end up in the sump. Shove a couple of shop towels in under the clutch basket before you do any gasket scraping, etc.

Here's what I found when I opened mine up for the first time:



What's wrong with this picture, boys-n-girls? Hardware-store bolts and washers. NOT a good idea in this application, those will be replaced.


LOOSEN THE PRESSURE PLATE BOLTS gradually and in a criss-cross pattern:




And DISASSEMBLE THE CLUTCH: Remove all of the pressure and plain plates and the clutch boss spring.



YOU CAN STOP HERE, there's no real need to remove the clutch hub, unless you will be replacing it.


IF YOU DO NEED TO REMOVE THE HUB, the best method of holding it to loosen or tighten the nut is a set of clutch holding pliers:



Be sure to fit a NEW TAB WASHER upon reassembly.

ALTERNATE HUB HOLDING METHODS: You can use a "strap" wrench but be careful of the basket ears; or you can screw or pop-rivet an old plain plate to an old pressure plate, slip that assemblage in, and put the bike in gear. Chacal carries the pliers and they are widely available on-line as well.

NOW THAT IT'S APART: We need to inspect the hub and basket for real wear versus "polishing:"



Note the "wear marks" left by the plates on the hub and basket. Run a fingernail over them, you should not be able to feel any sort of indentations, and your fingernail should not catch.

MINOR indentations can be smoothed out with a polishing stone; but only minor ones. Any major wear means the hub or basket will need to be replaced otherwise the plates will hang up and the clutch will drag or be erratic.

These parts are fine, with the exception of needing to smooth out the "nicks" left by the clutch boss spring on the hub (visible at the left of the pic.)

NOW INSPECT THE PLAIN PLATES: Usually, they just have "etched memories" of the friction plates thay sat next to for so many years, and can be cleaned up and reused:



The plate on the left is as-removed, the one on the right has been cleaned up with Scotchbrite and is ready to be reused.

Inspect for "mushroomed" teeth, or excessive wear/rotational gouges, etc. Don't re-use any plain plate that can't be cleaned up with Scotchbrite to look like new.


WATCH FOR SIGNS OF OVERHEATING: Here is a classic example of a truly burnt clutch plate, this one should NOT be reused:




CHECK FOR WARPAGE: Lay each plate on a small sheet of glass, and make sure it's flat. While the factory allows for "some" warpage, I personally don't re-use warped plates at all, there's no reason to.

Get your (good) plain plates all scrubbed fresh and clean and let's proceed.

INSPECT THE PRESSURE PLATE: As long as it's not burnt, or "torn up" and doesn't have any nasty rotational gouges in its working surface, it will just need to be cleaned up. This one's going to be fine:




After we PREP it: Use Scotchbrite (I use my Dremel, but you can do it just as effectively by hand) to put a nice "non-directional" finish on it, like a new brake rotor:



I also like to polish the area where the throwout washer rides but it's probably overkill.


MORE ABOUT THE HUB: As I said above, there's usually no reason to remove the hub for a "normal" clutch rebuild.

It has a "plain" plate attached to it; if it's loose or gouged up, it will need to be replaced, otherwise DO NOT DISASSEMBLE.

However, you do need to know about it. The plain plate is attached to the hub by means of a wire retaining ring:




Here's a closeup:




If it does need to be removed, the wire ring is released by squeezing the end "loops" together enough for them to pop back out the hole:



**NOTE** If you do need to remove the wire retaining ring, always replace it with a new one. DO NOT RE-USE the wire ring!


REFINISHING the hub's plain plate can easily be accomplished by sticking your finger with Scotchbrite wrapped around the end, (or the tip of your Dremel) in between a couple of the arms on the clutch basket, and then spinning the hub while you "attack" the surface.

It does not require removal of the hub.


Now let's CLEAN UP THAT COVER, and carefully inspect for any cracks, and inspect the throwout shaft gear teeth for chipping. Now's also a good time to take a handful of q-tips and clean out the oil level sight glass.



Use this opportunity to replace the oil seal at the top of the throwout shaft if it's been leaking. Otherwise, leave well enough alone.


Now's a good time to get a gasket ready; I like High-Tack Spray gasket, applied to the "cover" side only.




Round up all of your new and refurbished parts, and DREDGE THEM IN FRESH OIL:



I HIGHLY RECOMMEND using NEW factory bolts and washers, and NEW SPRINGS of your choice.


AND LET'S GET READY TO REASSEMBLE: First thing that goes in is a friction plate:




FOLLOWED by a PLAIN PLATE; notice that this first "tab" is straight up:




Then ANOTHER FRICTION PLATE, followed by a plain plate, note the orientation of the second tab:




Then another friction plate, followed by a plain plate, this is the orientation of the THIRD TAB:




CONTINUE ASSEMBLING, FOLLOWING this diagram for the tab orientation,




Until you get to your SIXTH FRICTION PLATE, which is the "special" one with the larger ID and the clutch boss spring:



(This belongs in the 3rd position from the outside, which is the sixth plate as you reassemble.)

NOTE: Bikes other than North American Market 550s may have two clutch boss springs and special friction plates as in the original exploded view.


I'm never sure exactly what to do with the FINAL TAB, since the book only goes to 6; so I position it at 180 degrees to #1:



FINISH WITH ONE MORE FRICTION PLATE, then it's time to:


REASSEMBLE the THROWOUT BEARING:



The wafer bearing goes on the "pull"rod, then the hardened steel washer to protect the aluminum pressure plate from the bearing;


And INSTALL in the PRESSURE PLATE:




And get it READY TO REINSTALL on the clutch pack:




Be sure to ALIGN THESE DOTS cast into the hub and pressure plate when reinstalling:




INSTALL your SPRINGS, BOLTS AND WASHERS, and gradually snug down in a criss-cross pattern:






Now let's carefully TORQUE them to specs, which on the 550s is ONLY 5.8 ft/lb:




REFITTING THE COVER:

-"Glue" your gasket to the cover;

-completely remove the throwout lever and spring from the end (top) of the throwout shaft.

-position the teeth on the throwout "pullrod" facing to the rear, in approximately this orientation:



And wiggle-fit the cover back on; snug and then torque the cover bolts.


THEN, rotate the top of the throwout shaft CLOCKWISE (viewed from above) until it STOPS, and reinstall the lever, return spring and clip.

The lever should end up so that when pressure is applied from the rear it STOPS as indicated here:




Screw your top adjuster (at the lever perch) in about halfway.

Reinstall your cable, and "raw" adjust it at the bottom, "fine adjust" at the top so that you have 1mm-3mm free play in the cable, and you're good to go!


So, that should cover the basics of a clutch overhaul on any XJ, and the granular specifics of doing a 550/600.

As always, let me know if I missed anything you'd like to see in better detail, or if you have any questions or need anything clarified.

COMING SOON: In the next chapter of "Clutches 101" we will pull apart the clutch on my ratty old 650 Seca and see what we find.

Happy wrenching--- Fitz

 

I have a question about the orientation of the pull rod.
When you took off the cover the teeth were facing almost 9 oclock.
When you put it back together the teeth were facing about 1 oclock.
My stupid question is. Does this turn?

 

Yes and no.

Until fully reassembled (cover back on) it not only turns but is free to pretty much "flop about" in the pressure plate.

Once the cover goes back on, its "D" shape effectively traps it in one position (in relation to the cover) so the teeth can stay engaged with the throwout shaft, and the pressure plate spins "around" it.

Go back and look at the very first pic; that's how it sits when the cover is on, in that pic the cover had just been popped off and the pull-rod was pretty much undisturbed.

 

Thanks, I know more dumb questions will follow. : )

 

They're not dumb questions at all. I had a heck of a time figuring out exactly how the whole thing worked until I took one apart for the first time.

It doesn't help that Yamaha calls the throwout stub a "pushrod."

 

Big, do I need an oem gasket to put this clutch side cover back on or can I use rtv? Just trying to find out if I need to order one. I have a new set of clutch plates and springs and I'm ready to do this per your how-to, but don't want to start until I know I'm ready.

mac

 

It's a pretty complex gasket, and the clutch cover is part of the crankcase breather system; plus because of the way the throwout mechanism works, the cover itself bears a load when the clutch is pulled in.

Because of all that, I highly recommend the correct gasket. Len has 'em.

 

Will do, thanks!

 

Fitz, I followed your guide to the tee, or so I thought, but once everything is back together, bike stalls whenever I try to put it in first gear. Tried to start it in first gear and it just lurches, any ideas? I did notice that the new plates stuck out farther than the old ones, figured that was wear, same number of plates and correct parts. Did put heavier duty springs on it and when putting the bolts with the springs on, towards the end of tightening them all I hear a loud pop like something was seating, is that normal? Sorry for all the questions, hoping it's something simple.

Mac

 

Mac, did you remember to adjust the clutch cable after the install?

 

I adjusted it the best I knew how to, but I imagine that it could be off. It seems right, pulls and releases like it did before from what I can tell, any pointers on what to look for?

 

http://xjbikes.com/Forums/viewtopic/t=2 ... cable.html

Just check out Rick's clutch adjustment procedure there. If you need pics then I can take some tomorrow afternoon after it stops raining.

 

Reading through it now, thanks a bunch!

 

Did you make sure the DOT cast into the pressure plate was aligned with the DOT on the hub? The "pop" concerns me; although it may have just been the bolts and springs seating.

The stalling and not going into gear, etc., means the clutch is dragging. Did you adjust the throwout lever as illustrated?

 

So I followed this instructions Bike runs great. When i took off the plates all mine were lined up with the dot. but your pic does it different . my bike is a 81 maxim xj550 so is it the last guy did it wrong or was it me?

 

You mean all of the tabs on the plain plates were pointed at the dot? That is most certainly wrong; they have to be "staggered" as in the article (per factory instructions.) The only thing that the dot is for is aligning the pressure plate with the hub.

 

do you know the torque spec for my '85 xj750 maxim x? specifically for the springs?

 

what is the torque spec for the large nut holding the hub in place as well?

 

Tell me if I've got this right. To adjust the clutch throwout:
Remove the lever, rotate the shaft clockwise, hold it there and re-install the lever, aligning the lever where it travels when the clutch lever is fully depressed.

Questions: What do I use to rotate the shaft with the lever removed? A string or shoelace a la Briggs & Stratton? Pliers? Can anyone tell me what to align the lever with on 750 Maxim? Maybe a pic?

Thanks

 

Almost. You can rotate the throwout shaft by hand. You want to reattach the lever at its best starting point, NOT the position of "full throw." You cannot, even with pliers, turn the shaft with enough force to actually operate the clutch. By turning the shaft CW until it stops, you've brought the "pull rod" up against the wafer bearing on the inside of the pressure plate. That's the point at which the lever needs to start pulling.

Make sense? If not, ask more questions. The whole thing muddled my head until I took one apart. Now, having done it over a dozen times, it seems really simple (to me.) It will all make much better sense once you take it apart and actually see how everything relates.

 

Thanks for the detailed write up! I followed your instructions and adjusted my cable accordingly but I'm having the stall when trying to put it i gear too...

When I got the bike (550) the plates were stuck together so I cleaned them up really well - now I've adjusted the tension on the throwrod / cable to the point where even in first gear (with engine off etc) I can turn the rear wheel without engaging the clutch (with resistance, just to see if I'm fully engaging the mechanism and if I could get a free spin like it should)...engaging the clutch then lowers the resistance but not enough to freely spin the wheel like in neutral

Any suggestions?

/edit - I found another thread where you were helping another member with this issue and it turned out to be incorrect assembly of the boss spring and special plate...mine didn't have either of those when I took it apart...just 7 metal and 8 black grabby plates

 

Great write up Fitz...............

Question.......

What purpose does the clutch boss spring serve?.... Release/take up wear/smoother engage?
Never have ran across that item before.

For what its worth my 82 550 came from the original owner.....Clutch cover has never been off it till I went in for a look see......Its like new! Friction plates and steels all measured out the same thickness,pressure plate could pass for NOS and the hub splines have shadow marks but nothing that will catch on a inspection probe/point......23,000 miles PO was not a hole shot type, just used it for transportation..............

The more I get into this XJ the more I like what I see. ...........

 

i think there is something wrong with my pressure pins? my bike will run great until i pull back hard on the throttle. when i do this, the RPM's soar but there is no output in speed. I just changed the oil in it today to make sure the previous owner hadn't put regular car oil in it. put in 10W-40, because yamaha doesn't make 20W-40 like the manual calls for. My friend thinks i should check the pressure bolts, and tighten/lossen them. (Bike also takes a while to shift between gears.)

Do you guys think this might fix the problem with the RPM's also?

 

Hey Fritz.........did all the "right stuff" but when I got it all back together I turned the throw out rod clockwise, connected the clutch cable and all. When I pull on the lever, it's locked solid and wont move. Did I do something wrong with the pull rod?

BTW, my bike is a 750

Regards,
Mike

 

My guess would be that you forgot to line the dot on the plate up with the dot on the basket and the pressure plate is stuck.

When you turned the shaft, prior to installing the lever, could you feel it moving the pull rod?

It sounds like something's jammed.

 

Yep..you guessed it.....didn't line the dots up. Right after I posted I went out and drained the case and pulled it apart. Sure enough, I didn't align the dots. Working fine now, just have to charge the battery from her long winters sleep.

Thanks for taking the time to post this here, it really helps us newbs to motorcycle maintenance.

 

You're welcome; the "dot thing" was covered, you know. The pressure plate and hub are not quite symmetrical; that's why it matters. The pressure plate only fits the hub correctly in one position, hence the dots.

I try really hard to plug as many "gaps" in the books as possible; glad it helps.

 

Yeah I got back in the house and jumped online to see if it was covered.......and i quickly found out I didn't follow one important thing.

Again........thanks for the help and info. Next I need to figure out what's going on with my Speedo, but that's a different problem all together.

 

Yeah I got back in the house and jumped online to see if it was covered.......and i quickly found out I didn't follow one important thing.

Again........thanks for the help and info. Next I need to figure out what's going on with my Speedo, but that's a different problem all together.

 

Very helpful write up Fitz. I pulled the plates out yesterday and noticed that the plain plates don't have any tabs on them as pictured. I'm assuming these are aftermarket plates because they look way too pretty to be 30 years old. So I'm wondering if some brands of aftermarket plates don't have the tabs and will this affect my clutch operation?

 

The "tabbed" plain plates are only used in the 550/600s; a 750 should have just "normal" round plain plates, and no "clutch boss spring inside a special friction plate" to worry about.

 

Thanks! I read about it not having the clutch boss spring but didn't see anything about the tabs. Good to know they aren't the wrong ones.

 

I'm not sure what "wiggle fit" means. I'm having a tough time getting my cover back on. The bolts are torqued down on my 750, gasket is "glued" on, and I turned the pull rod to 9 o clock.

The cover just gets stuck about a 1/4" off of the face of the engine.

What am I doing wrong?

This was a great write up, and I thank. I always screw up some mundane detail.

 

Thank you, and it doesn't sound like you've screwed up.

Take the throwout lever OFF if it's still installed. It's nearly impossible (and entirely unnecessary) to reinstall the cover and get the shaft to engage with the pullrod in the same "mesh" it had before. The lever could be stopping the throwout shaft from rotating as it comes into mesh with the pull rod.

The other possibility is that one of your dowel pins (the short, thin "sleeves" used to help locate the cover) is hanging up. There are two of them, located at about the 7:00 and 4:30 positions on the cover. Make sure they're fully seated. The screws don't locate the cover, they hold it on; the dowel pins do the locating. Sometimes they stay with the bike, most times they come off with the cover. (Oh, and POs sometimes lose them.)

 

Wow, you reply fast! Thanks.

I quit too soon. It felt tight, but it snugged down once I threw the allen wrench on it. I didn't want to force it, but I tried, and it worked.

Back off to, "rotate the shaft clockwise until it stops"

Damn, I need a laptop for the garage.

 

Only sometimes. Just got home, figured I check my PMs, etc., then I'm going for a ride.

Glad I could help.

 

Alright, I know cars, and this is my first venture into motorcycles.

I had the throw out shaft lever disconnected, and the throw out pull rod in the 9 o clock position.

I said that the cover felt too tight going on, and it was. I kept hearing a click as I tightened it down, and apparently that was the teeth of the pull rod and shaft gear jumping one another. I could never spin the throwout shaft by hand ("clockwise"). I tried to take the cover off, and the shaft gear and pull rod were hung up. I popped it off with a screw driver. I know that was wrong, but I was frustrated.

The pull rod is fine, where should I go for a new throw out shaft gear?

Any idea why I had to force the cover on, and it got all jammed up?

 

When i disassembled my clutch,I found that I have 7 plain plates!! What gives here?.,,, Mark

 

OK ,sorry ,my bad.There is supposed to be 7, I was just unsure of the position of the 6th and 7th tab,but I see what you were saying.Thanks... Mark

 

Yeah, the manual seems to have left the position of that last tab up to "mechanic's discretion."

Choices are to start over in the rotation, or go to 180 degrees.

I honestly don't think it matters. I'm not so sure the tabby plates achieve anything different than if they were just round; the Barnett's plain plates have no tabs and I've noticed no difference between it and the Yammie clutches.

 

:idea: Hi all , It seem's from looking in the 550 workshop manual , and having stripped my clutch that there is no spring that goes in the middle of the clutch plates !! Is this UK spec or has mine been lost over time ???

 

In the USA-market bikes, there should be ONE. Some of the Euro-spec bikes had two, as in the diagram before I corrected it.

Look closely at your friction plates. There should be one with a slightly larger ID, which is where the spring was supposed to be. If not, it's possible that somebody has already replaced the stack with aftermarket parts and eliminated the spring and its special friction plate. More likely it got lost along the way.

How necessary is it? I honestly don't know. The bigger bikes don't have any, and their clutches work fine. I suspect it and the tabby plain plates are anti-rattle measures rather than function-improvers.

 

Fitz,
Great tutorial; thanks for posting. Not sure if I'm just seeing things, but in the early disassembly pics, it sure looks like the alignment dots on the hub and pressure plate were 180 degrees out. Were they? If so, did the clutch function properly? And if so, was the culprit the same guy who used the hardware store bolts? Thanks again for all your help here.

 

No, he had that right. By the time you see the dot in the disassembly pics, the hub had been rotated.

The clutch wasn't working correctly; but it was due to the hub being LOOSE (thank you Yamaha for the tab washer) and 30-year old plates.

 

So, i took on the job of replacing the friction plates on my maxim after going through this how-to and everything was going perfectly until...

I had one of the five pressure plate bolts break off!

I was using a star pattern to tighten everything evenly, a torque wrench so that i didn't go to far, and had not had any problems up to this point. Now, i've got half of the bolt stuck inside the whole it screws into with no idea how to get it out!

Does anyone know a way i can get myself out of this blunder!?

Any help would be greatly appreciated

 

Sure. Take it back apart and unscrew the broken-off piece. The screws don't bottom out, it should turn freely.

If it won't easily back out, hit it with a small reverse drill-type screw extractor. As soon as it gets a "bite" the screw will back right out.

Hindsight always being 20-20, this is why new bolts are recommended.

The type of extractor I'm referring to uses a reverse-drill bit: http://www.sears.com/craftsman-7-pc-dri ... 952157000P

 

Thanks! I'll give that a try! Guess i was a bit over zealous in getting to work on the friction plate replacement to wait again for new bolts. Now, i know better.

 

see i always wondered, cause when i replaced my friction plates and bolts, i actually got the bolts from the yamaha dealer for 1.75 each, even though the old ones looked brand new when i pulled them off. makes me come to remember how the old ones were bright zinc looking silver color and the new ones were black/dark brown colored.

 

Well, I got the bolt extractors and got the old bolt out. Came out without a problem! Once the new bolts and washers came in i put everything back in the way you described, oddly enough though i had the same thing happen with a brand new bolt from the yamaha dealership. Yep, that's right, for some reason the brand new bolt cracked. I do have a good accurate torque wrench and all of the other bolts tighted in a star pattern at the right force, but when it came to this same spot i felt the bolt start to break.

I was able to back it out before it broke completely, but just barely. I tried using another old bolt and had the same problem. It wasn't until the third bolt of the night that i had one go in, all be it at about 1 ft./lbs less than the recommended torque.

After the second bolt broke i took a light and examined the threads; they all seemed to be in good condition. So, needless to say, i am quite confused as to what caused this problem. I have everything put back together now, with a new gasket and oil back in place, but have not started it yet.

 

What spec where you tightening it to?

I noticed when doing my clutch for my turbo seca, chacal actually sells a higher grade bolt that what I pulled out of my bike (w/ 6k miles, it's safe to assume it was factory).