Clutch, Gears, and Power after Oil Change

Hello everyone,

Just got done last night with an oil change on my 81 XJ650. I had gas in my oil from the PO: http://xjbikes.com/Forums/viewtopic/t=37126.html
I put a new Fram CH6003 (gotta say I love the rings that came with, and for $5 quite a bargain) and some Castrol 4T 20W50 Motorcycle Oil (which is on sale at AutoZone right now BTW...3 liters for $9.75)

I ran the engine for a while and let her warm up after the oil change and went to bed.

This morning I fired it up and noticed that my gears were VERY difficult to shift. I figured the oil probably just needs to cycle through a bit more. Left it running, and all worked out pretty smoothly with shifting eventually.

At a stop light, I noticed that I had the red light creep all of a sudden. I pulled over and looked a bit and my clutch grip bolt had fallen off somewhere. Wasn't too far from home and PO gave me a bunch of spares, so I turned around and slapped one on. Clutch pull feels a bit different now though and feels like the tranny doesn't start pulling the bike til about 60% of the clutch handle is released...odd.

After getting back on my way, I noticed some occasional 'slipping' once getting into 5-6k RPMs where engine RPMs would keep rising when throttle was applied, but no speed increase. This is definitely new.

I am wondering if the oil needs to 'settle' a bit more or should I say more fully saturate the gears...OR if the gas that was in the oil caused some issues with my clutch plates. I already know I need a clutch cable adjustment and lubriaction for sure.

Where to go from here?

 

You probably need to rebuild that 30-year old clutch; the gas in the oil didn't cause the problem, ~30 years' worth of sitting did.

By all means get it adjusted; but if it's both dragging and slipping, (what you described above) it's new clutch time.

 

I can see how that may definitely be the case, but it's hard for me to ignore that these issues didn't start happening until I drained and replaced the oil. No more than 12 hours ago I had full power range all the time with no slip.

But I agree that regardless, it is probably time for some maintenance on that clutch. Lord knows the PO didn't love her like I do and will.

Recommend a full kit or just friction disks for startsies? Any good sources?

 

At the very minimum, friction plates, SPRINGS, and a new gasket.

For parts, I'd recommend XJ4Ever.

 

You rock Fitz. Thanks!

 

Put the other oil back in

 

Hahaha! :lol:

 

I just wanted to put this link here for anyone else that stumbles on this thread with similar problems:

http://xjbikes.com/Forums/viewtopic/t=29541.html

A great write up on clutch inspection and overhaul by bigfitz52.

I plan on using it this weekend to at least see what is going on in there and report back. 8)

 

It's all making sense now. The old oil likely had some 'grit' to it. With removal of that old gritty oil and adding new, the worn clutch components are showing their true colors and the silky new oil is making slippage easier.

Looks like I'm going to be hitting Chacal up soon.

 

Does he need a spring? He has a 650. Are you talking about the external spring? I hear spring on these forums in regard to clutch and my mind immediately goes to that boss clutch spring I am so thankful that I don't have.

 

I'm pretty sure Fitz is referring to the compression springs (5 total) that connect to the pressure plate. No boss spring on the 650.

 

Still torn. I loosened the clutch cable a little for my ride home, and it made the slipping worse! To the point where I had to pull over because I was going too slow. (my thinking was that maybe the clutch wasn't disengaging and loosening it a bit would help)

I pulled over, and tightened it back up and it became driveable again.

I'm probably stretching, but I'm hoping more adjustment on the tighter side may solve this?

 

NO, rebuilding the clutch is going to solve this.

Clutch friction plates are a collection of little tiny brake pads bonded to a metal ring.

When an XJ is standing still, the clutch is half in/half out of the oil (ok, maybe 1/3~2/3) but part of it is sitting in oil, part of it isn't.

When a bike sits for a number of years, the friction "pads" that were oil soaked but no longer submerged dry out, becoming little squares of petrified linoleum. The pads that were submerged become oil-pickled and lose any material cohesion they once had. The little friction pads also tend to "weld" themselves to the plain plates, leaving behind a "memory" of them once they're broken free.

If you take a close look at the pictures of the "pre-refinished" plain plates in my article, you'll see what I'm talking about.

Then we come along and put the bike back in service with no consideration given to this horribly deteriorated clutch pack because we can't SEE it. After a few heat cycles and some nice fresh oil, those 30-year old petrified friction plates are NOT going to grip very well any more.

The clutch springs also tend to "sag" after all that time; fitting new springs just ensures that your new clutch won't slip.

The clutch (friction plates and springs anyway) is one of those things, like brakes, that simply have to be rebuilt to attain reliable operation from a 30-year old bike. In most cases, the original friction plates are far from worn out; they're usually just AGED out. The little friction pads get all black and crumbly at the edges and simply need to be replaced.

If you want the "brand new bike" feel, treat yourself to a new clutch cable at the same time.

 

Alright, so I am taking the advice and ordering my parts to get this thing overhauled.

What should I expect when I get this thing done? Should I take it easy for a bit on the throttle in the beginning?

 

It might be a little more grabby than you're used to. Be a bit ginger to start.

 

x2, we rebuilt the clutch on a buddies suburu sti, and for like a week after, it was like he never drove a manual in his life before, haha

 

Just be sure you soak the friction plates in fresh motor oil for at least an hour before beginning to assemble;

and be sure to "dredge" all of the parts in clean oil as you reassemble.

Take your time and be sure to align the dots on the pressure plate and hub. Use a torque wrench on the bolts, they don't go very tight.

Unless yours has been slipping horribly, you shouldn't notice much difference. You will need to re-adjust the cable after a few heat cycles and a couple hundred miles.

 

Thanks Fitz. She was slipping only briefly in the 5k-7k RPM range...just for a moment before catching again...that is until I adjusted the cable which I assume must have tightened the cable too much because in every gear it slipped ALL THE TIME giving me very low power. Rode like that for about 60 seconds before I said the hell with this!

I really need to learn the proper way to adjust the cable at the handle bar level and at the throwout arm, and I am guessing getting in there will give me a much better understanding with how the clutch system works.

I am guessing that pulling in the clutch disengages the clutch by pulling the pressure plate and compression springs outward which in turn seperates the friction plates and drive plates. If the cable is too tight then the clutch remains partially disengaged creating a loss of power and more slippage. If the cable is too loose, you don't get enough throwback and the clutch doesn't fully disengage when pulling in the handle...causing hard shifting, creeping, etc... Is this correct? How far should the throwout arm swing when pulled?

By the way, I am absolutely loving this. Any excuse to wrench is a blast, and in turn makes my bike perform better...which makes me even happier! Thanks everone!

 

You are correct in the operation of the clutch.

There is a spec for the freeplay in the clutch lever. Mine Seca's even got a plastic cover with a window that shows where the clutch and front brake lever should fall when released. If you put it in that range, and it slips, you won't be able to adjust it, you need to dive in.

When reinstalling the cable, you adjust at the bottom first, with the adjustment nut in the handle bar in a middle position, and get the freeplay close. Then you adjust the handlebar nut to fine tune. If you can't get the proper freeplay, adjust at the engine and then fine tune again.

 

Glad I am beginning to understand it!

In regards to the throwout lever, if all tension is released will it move pointing further down the case toward the rear of the bike? Or is it pretty much "home"? Also, how important is the spring around the throwout arm? Mine is apparently broken...I am guessing it is just a guide, but I want to be sure.

And just to clarify, I am asking not to adjust the cable as a solution as I have ordered the parts for the overhaul. But I am going to need to know this when the clutch parts and new cable arrive

 

OK.

The throwout arm can very much rotate "the wrong way" as far as it wants to.

Proper adjustment is to rotate the shaft clockwise (as viewed from above) until it stops, then reinstall the lever so that the little protrusion on the "heel" lines up with the dot on the case. When you rotate the shaft, it brings the pull rod up against the back of the pressure plate. You want the lever to "start" its pull there. Depending on how everything "stacks up" in the clutch, it may be necessary to back the lever up by one spline-tooths' worth to get a good throwout pull.

Yes, you need the lever spring, it keeps the cable/lever taught so that there's no "flop" in the mechanism. Len carries those too.

You have the clutch "theory of operation" correct. The throwout shaft rotates, and "drives" the gear teeth on the "pull rod" so that it can lift the pressure plate off the "pack" thus allowing the friction and plain plates to release their grip on each other.

Ideal clutch cable adjustment will give you 3mm free play at the lever with the bars straight ahead, and approx 1mm with them turned to full lock either way.

If you've had clutch-related problems, the difference once it's fixed will indeed be noticeable and immediate. But you do need that stupid little spring or adjusting the cable properly will be a challenge.

 

Fitz, do you have a picture of the spring?

Here is a pic of my spring, and it is hard for me to tell how much is munged on it as I have never seen what a "normal" one looks like. I don't know how much of that other arm is missing...



I have no problem getting a replacement, especially being that it is probably no more than a couple of bucks. However, the bulk of my parts will be here either tomorrow or the next day and I am getting the mini-van blues! 8O

Is this spring usable?

 

Problem may be solved. Local bike shop has what they think is the equivalent part to the spring. (Part#: 90508-16459-00 Torsion Spring)? It looks slightly different...anyone know if this will work the same?

 

It probably looks slightly different because it still has the hook on the end that's broken off yours.

That is indeed the correct spring, according to the fiche.

 

Haha! Probably!

 

Alright, started to get to work on the clutch tonight and I have a question about the plain plates. Mine are pretty black. I took some 1500 grit sandpaper (only one I had laying around right now) and the black does come off with quite a lot of elbow grease. No bluing, mushrooming, or warping. Other than the black baked on oil, they seem in tip top. Any better way to get this baked on oil off?

Here are some pics:

Before taking 1500 grit to one:




And after:



I want to be sure that these will be alright to use. I still have a bit more buffing out to do on the after pic, but I wanted to be sure before I continue.

They all look just like this. Are they going to be alright to use?

 

They should be. Get some Scotchbrite and they'll clean up even better.

Give 'em a "non-directional" finish, as in the pic below from the "how-to."

(This is a pressure plate, but the technique is the same.)

 

Thanks so much fitz! As always I really appreciate your help. Not looking to take shortcuts with my baby, but if I can save $60-$80 I'm sure the Mrs. would keep me in her good graces a bit longer...until the next project

 

Alright fellas. Got the clutch pack put back together properly, and new cable on.

Digging into the clutch, and having a better understanding of how the clutch assembly works is awesome. The cable and it's adjustment however, still giving me problems. The clutch is working, and working well I might add (after a pretty late joyride last night), but I'm not very happy with the clutch cable's adjustment appearance...just doesn't look right even though it works...which is half ass in my opinion and I'm not ok with that.

Here are some pics of how I have the cable currently:



The lower adjusting nut is mounted on the top of the bracket instead of the bottom. (this is the part that I really don't like) This is where it seemed to need to go in order for the throw out arm to be stopped before disengaging the clutch.




The adjustment nut is already several turns out.

Question: Should I turn the adjustment nut at the clutch handle out even more to bring the cable in more so that the nuts at the throwout bracket are 1 on top, 1 on bottom? Seems like it would take several more turns to do this...

 

STOP.

Loosen the upper adjuster lock ring, and screw the adjuster in to about half way.

Remove the little throwout arm, and "back it up" (counterclockwise) by ONE SPLINE TOOTH on the shaft.

Reattach the arm; at this point you should be able to put the cable into the bracket so one locknut is on each side of the part that holds the cable.

Then use the two locknuts to take most of the slack out of the cable.

Fine-tune up top.

Your little throwout lever is starting to engage too far into its arc. You need to back it up so it starts its actual "work" sooner, which will also give you the "sheath length" at the bottom to properly mount the cable.

One last item: You DID LUBE the new cable, right?

 

That's what I needed fitz, once again. And now it makes total sense! Damn, I feel retarded now. :lol:

Yes, sir...I lubed the cable very well til the lube made a nice mess on the paper towels I had bunched at the bottom of the cable. Slick as snot.

It is quite amazing how WONDERFUL the response on the bike is now. She just eats up those RMPS and the acceleration is SO FUN!