Can we compile definitive clutch slave cylinder fix thread?

[ckcarr]

Originally Posted by RBMann

Bill-
I am trying to cut back on my meds. and it is not working so well.count?

RB

Get out! Get out of the cinema... Can you distinguish reality from celluloid...

If not, return to Paonia...

[wswartzwel]

Originally Posted by ckcarr

Yopu have actually attracted the three wise men of the board...

The average lurker only attracts the resident Wise Asssses.

[wswartzwel]

Originally Posted by ckcarr

Get out! Get out of the cinema... Can you distinguish reality from celluloid...

If not, return to Paonia...

Like, 3 people on this board will get that joke

[j_hurricane_y]

I'm starting to figure out how this forum works ... knowledge is power, right Sen-se? Thanks to the knowledge bestowed upon me, by you the Almighty Wise Men, I was able to get this far tonight:


While I have your attention, however briefly that may be, is this much metal on the tranny mag drain plug normal with 7K in miles?

[wswartzwel]

Yes normal... small bits are OK.... large bits with readable casting numbers on them are not OK.

[wswartzwel]

Nice nails BTW... Manicured??

[j_hurricane_y]

With all the wrenching I did tonight, I almost forgot to share a couple PM's I got from jweicht who as I mentioned earlier seemed to have similar symptoms to what I experienced. Here's his first reply to my request to share more details of his experience and what he did to fix it:

After a few more years and a lot of other similar threads to think about it, I'm convinced the root issue on my bike was only failure of the clutch throw-out bearing. As the bearing was going bad, I believe that it set up enough wobble/vibration in the bearing/slave cylinder/push rod/gearbox seal area that gearbox oil was allowed to seep past the gearbox seal and into the slave cylinder and past its seal, thereby contaminating the clutch fluid with gearbox oil. I don't believe that any DOT 4 fluid escaped from the clutch system, it was all gearbox oil into the DOT 4 fluid. It's probable that gearbox oil was mixed with my clutch fluid for a while but everything still functioned normally. I only knew there was an issue when the throw-out bearing totally failed and I effectively lost the ability to disengage the clutch (exactly like a clutch cable breaking). I believe that the slave cylinder was still functioning properly (for the most part), there was just essentially no bearing to push on the push rod anymore.

As part of the fix for my bike, I was convinced that the rear gearbox seal was shot so I replaced it as well as installing a new slave cylinder/throw-out bearing and flushing the system with fresh DOT 4 fluid. As was stated in the thread you started, I knew that if enough gearbox oil leaked from that seal it could work its way forward through the gear shaft hole (alongside the clutch push rod) and contaminate the clutch (didn't want that, already had to change the clutch on my '94 R1100RS due to a bad "early model" design by BMW). To change the gearbox seal I had to pull the gearbox for adequate access, that's a real joy if you haven't done one yet.

In hindsight and if I had to do it all over again, I would not have changed the gearbox seal at that time. After changing the slave cylinder and flushing the system with DOT 4, I would have just run the bike and pulled the slave cylinder in 500 or 1,000 mile increments for a while to see if the seal was still leaking. In the end, I still think the only reason the seal leaked was due to the bad throw-out bearing and once that was no longer an issue the shaft may have run perfectly concentric again. If indeed the seal was bad and I saw gearbox oil after pulling the new slave cylinder, only then would I have pulled the gearbox and changed the seal.

On your bike, the amount of "liquid rust" present makes me think there was somehow an excess amount of moisture in the area of your slave cylinder. I didn't see anything in your thread about the actual condition of your throw-out bearing, or if had actually totally failed like mine.

I replied with "Thanks so much for your throrough reply! I am debating the gear box pull for the seal install. If I drain the gear box and see no evidence of DOT4 in it, can I safely conclude the mixing of the clutch fluid and gear oil was only one way? ... or is it possible the clutch fluid can travel all the way through the gear box w/o contaminating it, but still contaminate the clutch? I obviously don't have a handle on how it's all configured in there and the service manual doesn't make it clear to me. Re my throw out bearing, again I'm not sure how it's supposed to look. Mine didn't come apart as your did; no ball bearings. However it does flex/pivot; should it be rigid?"

His response:

Glad if I was able to help at all. Again I have to say that all of my response was based upon my experience and opinion, as I recognize that there are those who certainly have more experience than me in these areas.

Having said that, I'd say that yes, if you cannot discern any brake fluid in your gearbox oil then the liquid transfer was only one way (just like my experience, only gearbox oil into the clutch system).

On your second question, the answer is again yes, because there really is no direct connection between the two possibilities. By that I mean the gearbox input shaft is hollow and this is where the clutch pushrod resides and where it moves back and forth to disengage the clutch. The outside of the shaft rides in two seals (and bearings, of course), one at the front of the gearbox (just aft of the splined end of the shaft which engages the clutch splines) and one seal at the rear (just forward of the forward end of the clutch slave cylinder/throw-out bearing when installed on the gearbox). If DOT 4 fluid were to leak/escape from the slave cylinder it has two possible places to go: forward past the shaft seal into the gearbox and/or forward through the inside of the hollow shaft toward the clutch. So, even though fluid could go "through the gearbox to the clutch", it would only do so via a hollow shaft (the gearbox input shaft) and be totally isolated from the gearbox internals.

On my S, even with all of the gearbox oil/gunk I found when I pulled the slave cylinder the inside of the hollow shaft was dry (as it's supposed to be). There have definitely been cases where the rear gearbox seal leaked and the oil made its way forward through the shaft and contaminated the clutch, maybe I just caught mine before that happened or instead of going that route it went instead past the slave cylinder and into the clutch fluid because the bad throw-out bearing's gyrations made that the path of least resistance. That is my opinion of what happened to my bike: it all comes back to that bad throw-out bearing being the source of all the problems. Can't say that I ever read/heard of DOT 4 fluid leaking forward to the clutch but that's not to say that it hasn't happened.

As for your throw-out bearing, if there is much "play" at all on the end that engages with the pushrod, the bearing is going bad in my opinion. It is not a demountable ball bearing (not meant to be disassembled), therefore it should freely rotate but not really have play (or flex/pivot) to speak of. If you've already gotten your new slave cylinder you'll be able to compare a new/good bearing with your old one. Per my thread on the forum, I recommend that you liberally grease the balls of that bearing before installing it. My bearing was dry when I took it apart, I'd bet money that's why it failed in the first place and started my bike's chain reaction.

I don't mind you using in the forum any of the info (or my opinions) I've provided, and I'll be glad to help in any way I can.

Gotta love the kind souls out there willing to help a noob like me.

Note that despite what I believe to be good advice from jweicht regarding simply changing the slave cylinder and monitoring periodically, I decided that I had the bike far enough apart already that I might as well do a spline check and lube if necessary per repoe3's Dr. Splinelube thread.

[wswartzwel]

You also should be commended for your inexpensive yet stable and efficient platform.. Way to use your head...





Hope the straps are not tied to the garage door... your wife might hit the button to close the door.

[signit98]

...the things you pay attention to, Bill...

glad to see that you are in touch with the finer details of manhood...

[j_hurricane_y]

Bill,
Yes, the nails are the latest thing. Takes going into the garage for a few hours each day for 9 days straight to get that look. It's only for the dedicated. I'm certain you've sported it out and about as well; probably much more often than I. Thanks for noticing.

Yeah, I know I don't have much right to, but for some reason I'm pretty proud of my little platform...mainly for being able to make due with what I had lying around. I only had a ~50" length of 2x4 so I cut it into six 8" long pieces, screwed 'em together, and capped 'em off with particle board from a broken bookcase. Ghetto right? Not quite your custom engine stand mounted to a hydraulic lift, but it should see me through well enough. And no, the straps are not attached to the door. They are hooked through the brackets attached to the ceiling. I obviously try not to load them too much.

[wswartzwel]

:d

[wswartzwel]

I have a shop manual around here somewhere, and near the front of the book, one of the hand models has a blackened thumb nail from hitting it with a hammer... Near the end of the book, the nail has let go and is missing.

[j_hurricane_y]

Next time I bloody a knuckle, I'll get a shot for you.

[wswartzwel]

I have a weak stomach..

http://forums.pelicanparts.com/showthread.php?t=368426

[j_hurricane_y]

Holy crap! That's icky.

[wswartzwel]

Tuition is never cheap if you want a good education....

[j_hurricane_y]

I popped awake this morning dreaming of blown slave cylinders and dry spline shafts ... er, that didn't come out right. I got an early start and was able to get my gearbox off. Here's a couple shots that fill in the gaps in the process detailed by repoe3:
Airbox off (note I didn't find it necessary to disconnect the fuel lines from the tank, but may do so to make more room for reassembly).


Here's a shot with the starter off.


And here's just after the magic moment when the gear box was freed. Came off pretty easily actually; I'm sure it helps to only have 7K miles. Note I used a floor jack to support the weight of the gear box to keep things aligned as they came apart.


Fortunately the interior (input side) shaft seal looks nearly new. The felt is not stained by clutch/90W goo. The felt "seal" on the clutch rod seems to have done it's job, but it is saturated and was probably only a matter of time before it let the goo past. Here's a shot.


Last pic I have is of the throw out bearing in the center of the slave cylinder. You can see that the bearing race (I think that's what it is) is loose. When I get a new one, I will compare the two and post an update.


BTW, the splines on the input shaft look great. There's a Honda shop nearby so I got down there this morning to pick up their Moly 60 paste which I'll apply before assembly.

Back to the goo, I'm definitely going to change the "input shaft sealing ring at output end" (service manual language). Question, are the Bimmer tools the only way to go? Perhaps I'll take the entire gear box to Bob's and have 'em do it ... but I've done the rest of the job by myself so seems like wuss'n out to involve someone else now. Hmm ... maybe I can borrow a slide hammer from work ....

PS. Found this thread on an alternative method to getting to the gearbox/clutch. Looks trick.
http://forums.pelicanparts.com/showthread.php?t=401556

[RBMann]

Originally Posted by j

PS. Found this thread on an alternative method to getting to the gearbox/clutch. Looks trick.
[url

http://forums.pelicanparts.com/showthread.php?t=401556[/url]

That was mine. Having done three now I will give you my 3 cents worth. You can only hinge up the sub-frame on non-ABS models. Advantage- the wire harness stays in place, no need to remember routing and where the zip ties go, and the bolts line up for reassembly much easier. Disadvantage- the headers need to be loosened to allow the frame to swing up.

If you have goo in the trans. chamber where the slave goes then replace the slave cylinder, trans. shaft seal and the push rod felt. It does not matter weather the goo is trans. fluid, clutch fluid or water, you need to replace all the pieces. Trans. fluid ruins the slave seal and clutch fluid ruins the shaft seal.

And now my pet issue with this problem. Since the clutch fluid is under pressure, when you pull the clutch lever, and the trans. fluid is not, except thermal expansion, I do not see how trans. fluid can make its way to the master cylinder.

A link for seal replacement-

http://forums.pelicanparts.com/showthread.php?threadid=336607

The cheap work stand with 1" bore holes in the leg ends for straps. I bought a small baking sheet that will fit between the legs and catch debris.

Good luck, RB

[j_hurricane_y]

You 'da "Mann" RB.

If you have goo in the trans. chamber where the slave goes then replace the slave cylinder, trans. shaft seal and the push rod felt. It does not matter weather the goo is trans. fluid, clutch fluid or water, you need to replace all the pieces.

Exactly my plan; happy to have confirmation my t'inking is correct.

Since the clutch fluid is under pressure, when you pull the clutch lever, and the trans. fluid is not, except thermal expansion, I do not see how trans. fluid can make its way to the master cylinder.

Indeed! I clearly have nothing more to offer in way of explaination, but inquiring minds want to know!

Your stand is mo' better than mine; mine could defintely use some bigger feet for stability. Will have to swing by Ho' Depot at some point.

Thanks greatly for the seal install link. That's exactly what I've been searching for and the next step in making this thread comprehensive. I love this forum.

[jweicht]

Originally Posted by j_hurricane_y

Last pic I have is of the throw out bearing in the center of the slave cylinder. You can see that the bearing race (I think that's what it is) is loose. When I get a new one, I will compare the two and post an update.

Well jy, since you got my curiosity up during our PM exchanges, I decided to follow the thread you created here. From that picture of the business end of your throw-out bearing, let me assure you that your bearing is garbage. The inner race should not be cocked/loose like that.

And for all the familiar names I see who posted in the thread, .