Stuck gearbox

[jamestnewsonr65]

So I was out for a ride today for a couple of hours and then about 2 miles from home I tried shifting down/up and nothing.

The gear linkage is all as it should be and the clutch disengages when the lever is pulled, but the gears are not changing. The shifter just moves up and down without resistance.

Does this spell the end of the gearbox or is it something which could potentially be fixable? Im a novice when it comes to mechanics so it may be a case of swapping it out for a Motobins reconditioned one.

Any thoughts welcome.

[donbmw]

Sounds like the pawl spring broke. Cost to replace is more than the part.

Don

[Barry]

I'm guessing the gearbox does have one gear selected and that's how you got home. If so it does sound like the pawl spring. The part is cheap but some special tools are needed to get into the box and change it. Then you have the dilemma as to whether or not to replace bearings while you are in there and that might  depend on how miles are on the box. Except for the dedicated it's not an easy DIY proposition.  

[jamestnewsonr65]

Thanks for the replies, I think that getting a recon box would be a best bet then.

One I thing I did notice whilst investigating what was wrong was that after the long run when turning the back wheel I could hear a sloshing noise in the gearbox, but I guess this is just the viscosity of the oil after it is nice and warm.

[Tony Smith]

Thanks for the replies, I think that getting a recon box would be a best bet then.

I wouldn't do that, especially if my gearbox was otherwise in good order and condition. A Twin-shock series airhead that has reasonable maintenance and is not abused is a potential "life of bike" unit.

What I would do is remove the gearbox myself and deliver it to someone with the special tools and know-how to replace the pawl spring (depending on the date of your gearbox there may be a complete new shifter mechanism available which is apparently a good investment. Whilst your gearbox has its clothes off the person doing the work can give it a check over and if anything looks or measures as being on the way out - fix it. Bear in mind that an entire main bearing set for one of these gearboxes is less than $100 and the single expensive one that almost never fails is about $60 on its own (don't hold me to those figures, its been a while).

Also if your gearbox is pronounced to be in good condition, now would be the right time to buy a high ration 5th gear if you do much highway work. The high ratio gear-set costs like poison, but you will never get it installed so cheap. /I suspect that having your own gearbox refreshed, with the high ratio gears, will cost less than an exchange box of unknown age and past use.

[jamestnewsonr65]

Thanks for the reply Tony. After a bit of hunting around I have found a guy near(ish) to me who works on early bmw's but has recently specialised on the GS models.

Booked it in to him to have a look at the box and replace anything which needs doing. As you said I would rather keep the original box.

Will let you know how it gets on.

[NC Steve]

James, as others have said, the actual spring needed only costs a few dollars, as in less than $10, the real expense is in the labor. This very thing happened with my '82 last Fall, luckily I was stuck in 3rd gear, so was able to limp home, and later to the shop of our local, well known Airhead guru.

Long story short, I also gave him permission to "replace anything which needs doing", and after waiting 3 months, then finally having to demand the job be finished so that I could meet tax and DMV inspection regulations, I still don't feel that the job was well done.   I sincerely hope your guy will do the gearbox quickly and correctly, and not charge you for parts and labor that may not have been necessary!

[jamestnewsonr65]

I had some time today so took the gearbox out ready to take to Neil Harrison next week. He mentioned the replacement spring is about £0.60 but it's the labour that is the cost and the tools needed.

He's been working on these machines for 25 years and owned an r65 with the same problem.

I took the gearbox out by removing the swing arm as I wanted to check that all was ok after the rebuild last year. I had been noticing a little slackness in the rear end of the bike and was not really sure what it was so just wanted to make sure everything was ok. I'm taking it there next Wednesday morning and picking it up in the evening.

After getting the gearbox out I turned it upside down as some had mentioned and it shifted ok, which points to the broken spring also.

[Motu]

My pawl spring broke last year...a lot of work for a $4 spring. You don't need special tools, but you can make some stuff to do the job. Back on the road a couple of weeks later....takes 7 days for parts to arrive here from Motobins. I replaced the 3 springs on the shift mech, all seals and a couple of bearings. It was all good inside there, and I have a circlip on my '87.

[montmil]

Somewhere in an unused dusty corner of my head I recall someone, perhaps Snowbum Bob, offering a design of a simple bent wire that could be inserted into the gearbox and used to select a specific "get me home" gear. Stuck in bottom gear while 100+ miles from home is a distressful thought.

Anyone recall this? Could be a bit o' kit for the ol' tool roll. Guess I'll start a search.

[Barry]

Snowbum didn't invent it.  He got a agreement to display it on his web site and credits the originator.  It's the sort of thing that it would be good to play with while a gearbox was open so you would have a chance 0of making it work when the time comes.

I saved the drawing but have never made one.

[montmil]

That's what I was remembering. Figuring out how to use it, well...

[Motu]

Mine broke in 3rd gear, I was still able to ride home at 100kph.

[jamestnewsonr65]

I found a video demonstrating that very type of bent wire. Doesn't really show how to actually use it but shows the idea.

http://youtu.be/eZEFVstHv0c