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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: triplek on April 27, 2020, 09:31:43 PM

Title: Thrust piston on Clutch Release rod jutting out
Post by: triplek on April 27, 2020, 09:31:43 PM
My transmission after reassembly has the thrust piston on the release rod now sitting high and jutting out beyond the casing. It will not depress. This an odd one, to me at least.

Has anyone seen this before?
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: Paul_Waterloo on April 28, 2020, 09:22:21 AM
I haven't seen it before, I'm a newbie, but what is stopping it? The clutch rod that is sits on? If you pull it out, how far is the clutch rod, i.e. is this causing the thrust rod interference? If so, then the rod isn't full seated into the engine. You might have to take the transmission out to investigate if you can't figure it out.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: triplek on April 28, 2020, 02:46:05 PM
It seems it will be the pushrod not set right. I've removed but not yet replaced the transmission.

The pushrod is really tight in the main bushing, much tighter than other K's. I'd say unusually tight but I only have a handful of others to compare to.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: Paul_Waterloo on April 28, 2020, 02:58:03 PM
I have some pictures in my recent thread, they might or might not help.

http://www.motobrick.com/index.php/topic,13506.25.html
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: triplek on April 28, 2020, 07:57:16 PM
It looks like it just somehow didn't fully seat.  The rod is not bent. But this is definitely the tightest fit I've ever seen.

It's in now. It'll be a couple of days before it gets run. Thanks again to those who helped and those that looked in to see if they could help. Very much appreciated.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: Laitch on April 30, 2020, 08:58:44 PM
It looks like it just somehow didn't fully seat.  The rod is not bent. But this is definitely the tightest fit I've ever seen.
It might be that you failed to align the clutch components with the engine output shaft resulting the the clutch rod's hanging up on the diaphragm spring or the output shaft instead of entering the shaft smoothly. I use an alignment tool when installing the clutch components.

Please update us when you learn the cause.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: triplek on May 01, 2020, 12:29:17 AM
I used a clutch alignment tool, the 2 part version common to K-bikes that has the yoke bolted on and aligns the alignment tool itself.

I don't recall there being much difference in the strength of force my arms used to join the transmission to the engine and close the last gap, but I do guess I may have just over-priced it on the failed mating and just not have noticed.

I did note that the design length of the push rod in the system does allow it to miss the bushing and bolt in without exceeding the play of the thrust piston. Just barely, but it does allow you to miss and not blow out the thrust piston or bend the pushrod. Lucky for me.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: Laitch on May 01, 2020, 06:57:53 AM
I used a clutch alignment tool, the 2 part version common to K-bikes that has the yoke bolted on and aligns the alignment tool itself.
Please post a photo of that critter. I've only used this. I bought it from Ken Lively of Polepenhollow Tools (https://www.motobrick.com/index.php/topic,7833.msg56286.html#msg56286).
(http://www.motobrick.com/gallery/3/1601-010520071452.png)
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: triplek on May 01, 2020, 10:46:37 PM
This is it here
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: triplek on May 01, 2020, 10:48:46 PM
Another view here.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: Paul_Waterloo on May 02, 2020, 08:31:31 AM
Does that tool have a purpose besides aligning the clutch?

I was able to do my clutch without a tool. Glad I did not buy one.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: Laitch on May 02, 2020, 08:35:39 AM
This is it here
You indicate that contraption is "common to K bikes"; yours is the first I've seen. They must be regionally popular or esoteric. Anyway, I don't think it worked for you. Watch Chris Harris's video and use the alignment tool the way he demonstrates.

It seems to be an alignment or an assembly-out-of-order issue to me, if your description of circumstances is accurate. Many of us are likely to be interested in how you got crossed up in this procedure so please keep the updates coming. If you haven't already, you probably should disassemble right down to the intermediate housing and start over.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: The Mighty Gryphon on May 02, 2020, 08:57:59 AM
Laitch, that's the official BMW clutch alignment tool.  The purpose of the arms is to align everything to make it easier to get the real alignment tool through the clutch into the output shaft.

It's a classic example of BMW engineering.  Probably designed by an engineer they borrowed from the car division.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: Laitch on May 02, 2020, 09:17:41 AM
Probably designed by an engineer they borrowed from the car division.
Esoteric it is then. The Brick was developed by modifying an auto engine, so a gang of car engineers were likely in on it.  :laughing4-giggles: Nevertheless, something ain't right with its use as a talisman for reassembly in triplek's case.  :popcorm
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: triplek on May 03, 2020, 11:54:31 AM
The clutch was aligned fine. Remember that the splind hole is huge compared to the small rod. Nothing in the clutch itself can really obstruct the rod, not even if I'd have eyeballed the alignment.

I think that the rod simply did not seat into the bushing. I never, ever would have thought that were possible and would allow the transmission to bolt upon that condition. BUT - it really does appear that the system was designed with almost precisely the tolerance neccessary to miss and take up exactly that distance within the thrust piston full extension towards the back of the bike.

Lucky me, saved by the same anal bastards that build overkill unnecessary yokes for alignment tools.

Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: Laitch on May 03, 2020, 12:07:56 PM
Lucky me, saved by the same anal bastards that build overkill unnecessary yokes for alignment tools.
I can't tell from your response whether your still having a problem with clutch engagement or it was just a hallucination. Could you clarify?
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: triplek on May 03, 2020, 12:15:32 PM
Yes, it's in now and the thrust piston is functioning normally with full range. It looks like it just somehow didn't fully seat.  The rod is not bent. But this is definitely the tightest fit I've ever seen.

It's in now. It'll still be a couple of days before it gets run. Thanks again to those who helped and those that looked in to see if they could help. Very much appreciated.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: Laitch on May 03, 2020, 12:26:59 PM
Thanks for the clarification.

You haven't been a member long enough to edit published posts so try to get them right the first time. Consider it practice for mechanical work.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: triplek on May 03, 2020, 02:59:49 PM
You guys are a tough crowd. How long us the apprenticeship here? It's been 2800 days/400 weeks.
Title: Re: Thrust piston on Clutch Release rod jutting out
Post by: Laitch on May 03, 2020, 03:10:29 PM
You guys are a tough crowd. How long us the apprenticeship here?
It takes more substantive posts, not longevity.