Emergency shifting tool

[tvrla]

If I were you Carl, I'd be looking for a good replacement shifter mechanism. Either that, or get someone to take a close look at yours -- there's very definitely something wrong with yours and it needs to be corrected. These things don't break all that often - statistically speaking - and yours breaking that many times aint right.

That tech you mentioned that had it break riding it out of  the shop - he should have gotten wise to this right then! I mean, he pulled the transmission to fix a broken spring, and the new one breaks before the customer can even ride it!

[Barry]

Snowbum has some views on why the spring breaks :-

The last bit about post 81 transmissions gearboxes being immune doesn't seem to be bourne out by Bob W's experience.



WHY the breakage?   TWO reasons primarily. The early spring rubs on itself during operation, wearing itself thinner.    The spring may wind too tight on the boss,
causing excessive force on the spring.  Possibly some faulty springs, possibly a few other things; we just do not know.


Pawl spring breakage fixes:  One can  turn down the boss it rides on by about .060".  The boss needs to be
around 0.613" or below.  If yours is about .630, then machine it down.  Tom Cutter posted to the Airheads list that the original was 15.95-16.0 mm;
and the change should be to 15.55-15.6.   I don't hold to such tolerances.   Here is my take on the matter:
The post the spring is on has had its diameter changed in the 'shift kits'.  You can certainly reduce the diameter of the stock type.  The spring must
not bind-up in its operation.   Certain of the so-called 'shift-kit' parts, Pawl 23-31-1-242-892; and Segment (offset link) 23-31-1-231-578,
supposedly will 'cure' broken pawl spring problems....but modifications work well. As noted in 6B, above: The OFFSET segment for pawl
spring clearance was one of BMW's changes.   What has not been said hardly anyplace, except perhaps Anton Largiader's page, is that the Shift Kit,
incorporated by the factory since sometime late in 1981, will keep the pawl engaged, if the spring breaks.

[R65LS]

 wirespokes,

 I couldn't agree more ..... but have been unable to find a private person in SoCal with the knowledge of how to take all this apart.
  --  which is to say, the only people who can do the take apart are the mechanics employed by the local BMW dealers, and they are "not" very interested in such a private project.

Cheers,

Carl

(edited to add "not")

[tvrla]

...and they are very interested in such a private project.

I'm sure you meant to say " they aren't very interested in such a private project."

I can understand that - 'just get the thing fixed, getcher money, and go home!"

I figure it's something like what Barry just quoted - the boss being too large in diameter, which stresses the spring under compression. No idea why or how that could have happened, but that's my first suspicion.

[R65LS]

 wirespokes,

 oops .... you are correct ..... I edited my above post to add "not"

 Yep, I've looked around a bit for a local BMW enthusiast who can handle a transmission disassembly but haven't found one.

 On The Other Hand:  is it that tough for a shade-tree mechanic ??  I've been scared of it, because I heard many years ago that there are special tools necessary to get a transmission apart (and reassembled).  And of course, "secret" knowledge about the inside pieces and parts, and how all that fits together .....

Cheers,

Carl

[tvrla]

Well, yeah - it does take special tools to remove the U-Joint flange, but that's all you'll need to get inside.

If it's shifting fine, then reshimming might not be necessary. However, sometimes the shims fall out of the bearing pockets and get mixed up when removing the cover. Then you're screwed, as the special tools will be needed to figure out which goes where.

The transmission is a puzzle in that some parts can't be extracted without first removing someting else. And the proper technique for working on them is important, otherwise expensive parts can be damaged; things like knowing how to heat the cover, how to reset the shafts, checking for play when it's back together...

[R65LS]

 So, the smart play is to find someone local who knows what they are doing ...

 AND of course, the obvious question is:  why the heck does this pawl spring problem even exist ??
  ---  more of a rhetorical rant/chant as to why either the BMW engineers, or the much smarter community in general, hasn't figured it out ??

Cheers,

Carl

[tvrla]

Who knows, Carl? Nothing's perfect, that I've heard of. There's always some down-side to put up with. So you pick what does best for you, and has the least negatives - or at least the ones you can live with.

Some like to think the German engineers designed the most perfect equipment. And then they're upset when something breaks or doesn't work right. All things can break, just a fact of life.

But I agree - why not have it fail in a working mode rather than total failure?

It's kind of like the Motometer speedometers - there's a gear that tends to slip rendering the odometer inoperative. This lasted the whole run of airheads from 1970 to 1995. They never changed it! I've heard the same thing about VW and BMW car speedometers, except with them the gear is plastic. Never changed. Someone finally made metal replacements, but not Motometer (or VDO, don't recall which).

It doesn't help getting upset about it - it is what it is, so let's do what we can to resolve it. Springs do break, and sometimes there's something defective, something machined wrong, who knows? Maybe it got dropped on the assembly line and now there's a mis-alignment causing all the problems. Or something's binding. Now it's a puzzle and someone who's willing to take a good close look, and knows what he's looking at, needs to check it out.

In your position, I'd find another transmission, make sure it's in good shape and install it. Then have the original looked at and the trouble found. I would't want to ride a bike farther than I could push it home if I knew it had a ticking time bomb for a pall spring.

[montmil]

I'm thinking that ol' 'Spokes is traveling along my thought trail. There just may be more wrong within that specific R65LS gearbox than bad pawl springs. Four breaks speaks volumes.

Reminds me of some of the death-knell Meriden Triumph factory fiascos brought on by their use of mix n' match, wash n' wear bits used to cob together sorta-complete bikes from the leftover stores of years gone by.

"The Japanese will never be a threat to the British motorcycle industry" - Edward Turner

[R65LS]

 as always, the best advice is always found here !!

Cheers,

Carl