Clutch problem , slipping

[SJK]

Have you verified that there is no bushing in the assembly forward of the puck?

Yes , with the Gearbox removed the Piston/Puck goes nicely into position. I assume as there is nothing stopping the pushrod from sliding thru

[Filmcamera]

It does sound like something is up with the clutch pack which is not allowing the clutch pushrod to go in as far as it needs to. You sure you have the clutch the right way round etc.?

[Motorhobo]

To what Gryph said -- I had a similar problem once -- mentioned a thread about it here earlier but forgot to include it -- here it is:

http://www.motobrick.com/index.php/topic,7086.msg48744.html#msg48744

The relevant bit is:

Issue 1) Spring slipped out of position during clutch pack alignment. Result: clutch pushrod is obstructed from bottoming out where it rests on the spring, which prevents the transmission from sliding forward into place. To prevent this:

1 -- Before removing clutch pack: -- insert the clutch pushrod as far forward as it will go, pinch it between your thumb and forefinger, pull it out, and measure the distance from your thumb to the tip of the rod. Doesn't have to be exact but it should be in the 2.125 - 2.25" range. This is the 'before' measurement.

2 - Install the clutch pack and make sure the distance the clutch pushrod slides forward matches the 'before' measurement above. If it doesn't, something's not right -- shine a light in the bore and confirm that the spring isn't centered. At this point you'll have to install the clutch pack as many times as it takes to get it aligned right. Note that every time you do it the tooth washers will lose integrity -- can't hurt to have a couple sets of these on hand.

=================

Like I said, though, if the rod isn't all the way in the clutch pack where it belongs, wouldn't the transmission not go on at all? Anyway, if the rod isn't going in about 2.5 inches as stated above, then that's the problem -- or the problem is behind the clutch pack although I don't know how that could be.

The rear end of the puck has a bearing into which the tip of the rod slides. The bearing should be flush with the rear face of the puck. Is the bearing flush or sticking out?


The only other alternative is that there's something causing too much space behind the clutch pack...but I don't know what that could be. I have a spare engine with the clutch housing still installed -- I can measure that distance if you can give me reference point you want me to measure to/from.

[SJK]

Are you using a pair of 8mm x 100mm headless bolts to support and guide the transmission onto the rear of the engine to assure alignment?  A tiny bit of tilt in the transmission during installation will mess up the alignment of the splines and the pushrod.

I am pretty sure that you are not getting the forward end of the rod into the pilot bushing in the engine output shaft when you install the transmission.  That is the only thing that would force the rod as far back as you are experiencing. 

How did you center the clutch pack?

I used a #13 socket and the Pushrod to align the Clutch pack. The first few times I just aligned everything and slid the gearbox back on with the Pushrod already in the gearbox....
I have now tried leaving the Pushrod in the clutchpack (so I could confirm its in all the way to the pushrod rim) then slid the gearbox back without disturbing the Pushrods position in its most forward place ...........but as I bring the gearbox closer to the bellhousing the pushrod greets me at the back(too far out)
Yes I used guide bolts to slide Gearbox in and out as I was afraid of bending the Pushrod.

[Motorhobo]

Something's funky with that pushrod -- either it's not going into the clutchpack the required app. 2.5inches or it's not seated in the puck where it should be.

Again -- it might LOOK like it's going into the clutch pack all the way, but that doesn't mean it is. It needs to go in about 2.5 in. If it's not doing that, there's your problem.

[SJK]

It does sound like something is up with the clutch pack which is not allowing the clutch pushrod to go in as far as it needs to. You sure you have the clutch the right way round etc.?

I am unfortunately sure but unsure if the correct parts are used , this bike has been worked on by dodgy mechanics/owner in its life before me, Its never worked for two years now when I bought It striped. been a struggle to resurrect

[Motorhobo]

Hey, I'm a dodgy mechanic too. We're not bad people.

Measure the insertion depth. 2.5 inches give or take a quarter.

[Filmcamera]

Hey, I'm a dodgy mechanic too. We're not bad people.

As another dodgy mechanic I can also state that I am not a bad person - just a bad mechanic!

[Laitch]

. . . been a struggle to resurrect

If resurrection were easy, everybody would be doing it. :giggles

[SJK]

To what Gryph said -- I had a similar problem once -- mentioned a thread about it here earlier but forgot to include it -- here it is:

http://www.motobrick.com/index.php/topic,7086.msg48744.html#msg48744

The relevant bit is:

Issue 1) Spring slipped out of position during clutch pack alignment. Result: clutch pushrod is obstructed from bottoming out where it rests on the spring, which prevents the transmission from sliding forward into place. To prevent this:

1 -- Before removing clutch pack: -- insert the clutch pushrod as far forward as it will go, pinch it between your thumb and forefinger, pull it out, and measure the distance from your thumb to the tip of the rod. Doesn't have to be exact but it should be in the 2.125 - 2.25" range. This is the 'before' measurement.

2 - Install the clutch pack and make sure the distance the clutch pushrod slides forward matches the 'before' measurement above. If it doesn't, something's not right -- shine a light in the bore and confirm that the spring isn't centered. At this point you'll have to install the clutch pack as many times as it takes to get it aligned right. Note that every time you do it the tooth washers will lose integrity -- can't hurt to have a couple sets of these on hand.

=================

Like I said, though, if the rod isn't all the way in the clutch pack where it belongs, wouldn't the transmission not go on at all? Anyway, if the rod isn't going in about 2.5 inches as stated above, then that's the problem -- or the problem is behind the clutch pack although I don't know how that could be.

The rear end of the puck has a bearing into which the tip of the rod slides. The bearing should be flush with the rear face of the puck. Is the bearing flush or sticking out?


The only other alternative is that there's something causing too much space behind the clutch pack...but I don't know what that could be. I have a spare engine with the clutch housing still installed -- I can measure that distance if you can give me reference point you want me to measure to/from.

Thanks so much for helping out...im really stumped and appreciate any suggestions .

-The pushrod goes in all the way to the brass bushing of the diaphragm spring plate at the back of the clutch pack assembly so I would think that's right, and the gearbox slides in nicely all the way(but the pushrod then moves out the back)
 
-I just checked and the measurement is as you suggested 2,5''.

-the bearing on the piston is flush

-I was also wondering if the Clutch housing is maybe too far forward, and I had BMW confirm that it is the correct part for my model.
PLEASE if you could measure the distance from the back of the bell housing to where one of the six clutch housing bolts would fasten I get 25mm , that will help greatly

[SJK]

 :hehehe trust me you guys have been more helpful and assisting then the run in I had ...really appreciate

[Laitch]

Have you removed the rod and placed the puck on the end of the rod to see if the rod is fully engages into it?

[SJK]

Have you removed the rod and placed the puck on the end of the rod to see if the rod is fully engages into it?

yes sir

[Motorhobo]

Clutch housing depth looks like about 5/8" -- pic shows how I measured it. You can do the kooky metric math -- why anyone would want to use units that make sense I'll never understand.

That's a joke there...you haven't been around long so you may not have guessed that most of us don't take each other very seriously.

[Laitch]

That's a joke there...you haven't been around long so you may not have guessed that most of us don't take each other very seriously.

It ruins it when you tell them that.  :nono

[SJK]

hahaha ok thanks ill go dig out the old rusty dusty imperial toolbox  :hehehe

[Elipten]

Post photos of your clutch pack and everything else.  Maybe one of the wise men will spot something


Sent from my iPad using Tapatalk Pro

[SJK]

Clutch housing depth looks like about 5/8" -- pic shows how I measured it.

 I am measuring 1" from the back of the bell housing to the flat face of the clutch housing (where the bolts go)
are you getting 5/8'' form the back bellhouging to the dish (where the wire ring is)??

[Motorhobo]

No, I was measuring from the flat of the clutch housing at its lowest point, not the raised section where the bolts go. I think for comparison it also needs to be measured at the same position in the bell housing, in case the depth varies at different positions. I'll do another measurement and take a picture from further back so you can see where I measured -- that's not clear in the last pic I posted. I'll do that later this morning.

In the meantime, maybe it would help to get a picture of the rear face of the puck and the rear end of the transmission with the rod sticking through so we can see how far it protrudes rearward with the puck off. I have an extra trans, rod and engine lying around for comparison.

Did you do the rear main seal replacement? If so then you must've had the clutch housing off and would know what's behind there, or?

[SJK]

Ok thx , if you could measure in the same spot as mine please.


I'm attaching all the photos

[SJK]

With Pushrod insurted to its max from front of gearbox

[SJK]

With Piston/puck insurted to its max into the gearbox

[Filmcamera]

What year is your K75?


Looking on Max BMW there is a note by the piston which says


"The following note only applies to models that had a bushing on the original push rod.[/size] This part replaces the older throwout bearing and piston. The 167 is a combined/sealed unit. When installing this part on your older clutch rod, there's a bushing that is not needed and must be removed. Otherwise, replace the clutch rod at the same time as it made for the new 167 part[/b][/size]."
[/size]
[/size]Maybe, just maybe, you have the new piston but the old clutch rod?

[SJK]

What year is your K75?


Looking on Max BMW there is a note by the piston which says


"The following note only applies to models that had a bushing on the original push rod.[/size] This part replaces the older throwout bearing and piston. The 167 is a combined/sealed unit. When installing this part on your older clutch rod, there's a bushing that is not needed and must be removed. Otherwise, replace the clutch rod at the same time as it made for the new 167 part[/b][/size]."
[/size]
[/size]Maybe, just maybe, you have the new piston but the old clutch rod?

 :eek:  I have a old 1989 model!! so maybe that's it .... someone must have upgraded to the new puck and did not know about this modification to the piston/puck . did you find any info on how to remover the bushing

[Laitch]

I have a old 1989 model!! so maybe that's it ....

You were asked about the existence of that bushing in a previous post. We still don't know if it has one. Remove the rod and take a photo from the swing arm side.

Please put the year of your bike in your profile so it will show up in every post. That way respondents will know exactly what is being repaired and won't need to backtrack.

Call a dealer and ask them the length of the clutch rod they would supply.