Topic: Clutch!!!! What am I missing ? (sunday 4/13)

[greenjeans]

72 CB750K   modified post....read to the end please.

[Tower]

Yes tighten down completely.  Just do it in 1/4 - 1/2 turns cross-pattern to make sure no one bolt is tightened down further than the others (otherwise the lifter plate will break)

"Hook" just means to push the washer onto the splined shaft>  It will "float", as you put it until the clutch centre assembly is in place.

[Tower]

to your third question: After assembling the friction disks and plates, set them with a snap ring.   Place a dial gauge against the end of the clutch assembly and check for looseness. if greater than 0.004" (0.1mm) install a spacer on the inside of the snap ring.  Be sure your clutch plates are oil soaked when taking the measurement, otherwise you will get an overly loose measure - if you then shim to that, you will have a clutch that will not disengage properly.

[greenjeans]

Shims..... there were none when I took apart.  Are there supposed to be some ?  and where to they go ?

[Tower]

There may not have been any shims originally.  They come in three different sizes 0.1mm, 0.3mm and 0.5mm.  They go in right before the snap ring goes on.

Shims are only needed in time, as the clutch assembly loosens against the main shaft, or in original assembly, due to manufacturing variances in the clutch inner.  Although the specs say 0.1mm tolerance, I'll bet as much as 0.3mm is still not a problem.

[mystic_1]

Another thing to watch out for while you're in there is the alignment of the pressure plate splines with the clutch center splines.  It's not obvious at first and is easy to get wrong.  See THIS POST for more info.

cheers
mystic_1

[greenjeans]

thanks Tower & mystic I read that other post as well, and noticed that the friction discs/plates are in first before the clutch outer ring in installed.... I've been stacking the plates/discs in the outer before putting them into their place.  Is that what's tripping me up ?  It came out in one big assemly, so I figured it went back in the same way ?

Ok one last thing - Snap ring ?   I don't see any mention of it in my manual & there was not one when I took it apart.

Should there be one, and where does it go ?

And one more...the last pic in the post shows the orientation of the friction discs, are those backward or correct? (to fling the oil)

[Tower]

This is the usual sequence for removal:
-Unscrew the the four clutch pressure plate mounting bolts, and remove clutch pressure plate and springs.
-Remove clutch lifter piece
-Remove snap ring, shims (if any) and clutch assembly from main shaft (Your clutch may not have a snap ring, instead it may have a lock nut and tongued washer and spring washer)
-Disassemble the clutch discs, plates, and clutch centre from the clutch outer
This is the usual sequence of assembly:
-Install the clutch outer to the mainshaft and then install the clutch centre
Assemble the oiled friction discs and clutch plates on the clutch center, and then, assemble into the clutch outer. Make sure the grooves are facing /// when looking at top left of clutch assembly. i.e. if the shaft were rotated counterclockwise the inside end of each grove should proceed the outer end of each groove going into the turn.  As per my note to zeus87 - reverse to what he has in his photo
-after all the discs are assembled, put shims and the snap ring onto the main shaft (On your clutch it may be tongued washer, then spring washer , then lock nut)
If you have a lock nut, then shims are not required.

[greenjeans]

Ok here's where I am....
I will mention that the clutch DID seem to be working before I ripped into it.  I still have yet to ride it.  It's been sitting for at least 6-7 yrs, so I'd figured I'd take apart the clutch, clean things up and make sure things aren't sticking together etc.  Everything is clean, oiled and lined up. 

I followed the procedure for adjusting the clutch (Honda manual)  loosened cables, loosened locknut and then turned the adjusting screw until resitance was felt, backed it off 1/4 turn and then snugged the cables back up.

It feels like it did before - smooth and how I would it expect a clutch lever to feel....yet it's like it is still compressed
can't get the wheel to turn while in 1st gear w/ the clutch pulled in.

Any ideas ?

[Tower]

First, isolate whether the problem is in the cables or in the clutch.  To that end: remove clutch adjusting cover and manually accentuate the lower clutch lever.  This should disengage the clutch (free up the wheel) indicating the the problem is in the cabling and/or cabling adjustment.

If still not freeing up, then the problem is either in the clutch cover mechanisms or in the clutch basket assembly. (My vote would be the basket assembly)

[greenjeans]

Gotta be the basket assembly...I think.  Cable moves freely and pulls the lower clutch lever so It's not the cable.
Should I be able to move the lever lever easily ?  I've had this thing apart 3 times now and just don't see any other way that it (discs and basket) could go back togother...

If I am understanding how this works.... if there is no tension on the cable - ie not attached... I shouldn't be able to move the wheel in 1st gear correct ?  Meaning that the discs are 1. LOOSE or 2. SMASHED TOGETHER - for lack of better terminology.  Pulling the cable rotates the arm which rolls the little balls out of their slots and pushes the pin on the backside of the lever into the basket assembly (the little hole it fits into) and applies MORE pressure ?

I'm going out to take another look....back in a few

[754]

You have a misalignment on the pressure plate or one of the ther plates..when you put the alumminum piece in, it has to fall in the grooves.. 4 ways to do it & some dont fit..

[Tower]

The lower lever will not move easily - its pushing on 4 springs. With the lower lever disconnected the clutch is "engaged" i.e. all the disks are pressed against each other.

Next test:
Remove the clutch crankcase cover and test it first. With the cover on a workbench so that the lever is up and the adjusting bolt is down, accentuate the lever (this time it will be easy). The entire clutch cover should move up. If not, then the problem is in the cover mechanism.

Assuming its the basket then:
disassemble the clutch inner from outer and take out the clutch plates and disks. First count them. There should be 7 friction disks and 6 plates.  (Some clutches were factory repaired so that they have 6 friction disks and 6 plates - one of the middle plates is a double plate. Some could have been upgraded to K6 longer inner/outer baskets, lifters and covers making room for the double plate as well as the 7Th friction disk. This is a key consideration with issues such as yours)

Measure the thickness of the friction plates
Measure that there is no warpage in the plates

If all checks out, then you could have misaligned the splines on the baskets (180o off)  Reassemble correctly.

[greenjeans]

Lever works fine...I'll take it out AGAIN - luckily I'm stubborn, so I won't give up.
What I'm calling the basket The 2 aluminum pieces that hold the discs/pressure plates and the plates/discs it looks like you just can't mess it up...All the plates (correct number - I counted again just to make sure) are there and it fits together like a glove.   I guess I'm just missing how it installs into/onto the main splined drive...I guess I just haven't seen how it could go on in different directions....looks like you could put it in there any number of different ways and still get it in.  Unfortunately i have a barbeque to go to so I'll have to report back tomorrow.....

Thanks for all the help and suggestions.... stay tuned tomorrow.  With your help I'll defeat this CLUTCH!

[Tower]

A count is sometimes not enough to confirm the correct assembly. 

Counting from the rim of the clutch inner basket it should be:
stock plates:                F P F P F P F P F P F P F Pr
or, stock basket:          F P F P F D F P F P F P Pr
or, K6 parts:                F P F P F P F D F P F P F Pr
F - friction disk, P - steel plate, D - double steel plate, Pr - Pressure Plate
ensure the right combination of plates are in the basket.

Severely warped plates could also cause this problem, as well as clutch slippage while riding.  So, ensure the warpage in the steels is within tolerance.

You may also have a problem in orientation of the pressure plate with the clutch inner (is easy to misalign since there are four positions that seem to fit).  This causes misalignment of the lands/grooves of the clutch centre with the spline cuts in the pressure plates.  With "severe" binding, the typical result is a broken lifter plate when tightened down.  To avoid problems of engaging as spring tension increases, pull the pressure plate forward and onto the lands/grooves of the clutch inner while beginning the tightening sequence.  You'll notice right away if there's an alignment or binding problem.  Tighten down so that the posts on the pressure plate touch the lifter when fully tightened.

In some cases, failing to mesh the teeth can cause "moderate" binding of the teeth on the plate with the grooves on the clutch inner with the result that the pressure plate is wedged against the clutch inner causing the symptoms you're experiencing. Consider yourself lucky that the lifter ear didn't break instead.