1982 GS650GL. 2nd gear is busted. Time to take apart the engine

[William Groebe]

Hello, good people of the GSR forum.

I recently purchased a 1982 GS650GL that has no 2nd gear. When I put it in 2nd and apply any throttle at all it skips out of second, sometimes dropping back into 1st. The PO assumed the dogs on 2nd gear may be worn down, but I won't know until I crack open the case.

Switching from 1st to 3rd is not so bad, and besides 2nd gear the bike runs well. There is a lot of vibration in the bike at high RPM which makes everything in the mirrors blurry, and that is a little disconcerting. I like to see who's coming up behind me, but on the freeway all I can make out are blurry shapes.

Most recently oil started leaking from the head, and so I've decided that instead of having my wife kill me because I'm getting oil all over my jeans every day, I'll go ahead and fix the oil leaks and 2nd gear, and hopefully the vibration problem will go away once I find out and fix whatever the problems are with the transmission.

There is also a lot of rust on the bike, but I'm going to wait until the rainy season before I do a full beautification process.

I started to take the bike apart on Sunday. I wanted to get as far as taking the engine out, so that I could crack it open and start ordering the parts I need, but as usual on any project, it's taking longer than I'd anticipated. I almost got all the brackets off last night, but one nut is stuck.



It is so tight, when I tried to get it off the extension bar on my wrench broke. yikes!


I sprayed some Liquid Wrench on it and will have to wait until tonight to try again.

I'll be posting my progress along with any questions I may have along the way. I've got a service manual from BassCliff's website (Thanks BassCliff) and will be referring to other threads on this site as well as I go. Feel free to throw out any recommendations when you have the urge to do so. I have no ego, and this is my first time breaking open an engine, so I'll need all the input/encouragement I can get.

 

[huntb]

If worse comes to worse you could carefully dremel the nut off. Make slits 180 degrees from each other and try to not damage the threads on the bolt too badly. That or you might be able to rent a nut splitting tool from your local parts store. Good luck with the tear down!

 

[tom203]

I can fathom losing 2nd gear ( this takes lots of abuse from novices) but the vibration stuff is disturbing - are you in 5th gear ? This 650 shafty trans is rather unique in that in fifth ,second gear is slid to lock up the input from clutch to output shaft feeding the secondary drive. Hard to explain but if you look at attached pic. On front shaft, second gear is the one that has lower set of "teeth" - this slides into the gear driving the bevel gear to get 5th.
Getting parts for this will be expensive- might be more economical to find donor engine.

 

[William Groebe]

Thanks for the info, tom203. As far as the vibrations go, it happens when the RPMs are high regardless of what gear I'm in. I'm hoping that once I fix whatever is wrong with second gear the vibration issue will go away, or I'm hoping that something obvious is fixable in the engine. Regardless, once I fix the transmission I'm going to put it back together and we'll see if it still vibrates at high RPMs. A friend recommended putting rubber washers between the engine and the mounting brackets, but that seems like a work around, rather than a fix. We'll see when I get there.

On another note, I got the engine out this morning. The Liquid Wrench did it's job and I pulled out all the bolts and mounting brackets, and did the "tip the bike onto the ground on it's right side" method. But I couldn't seem to get the engine out, until after about 15 minutes of wrestling and wrenching around my garage floor, I realized I could just take out the airbox, and the engine dropped out just fine. I tried lifting the engine up onto my worktable, but my back said No Way Jose. I'm going to have to see if I can get a friend or two to help me lift the damn thing.

Here you can see the airbox output section (or whatever it's called) getting in the way of the engine falling out.



I taped up the right side of the frame to try to mitigate any damage as the engine comes out.
In retrospect I should have doubled up on the tape as the engine scraped through the tape in a few places.



Success! You can see where I labeled all the wires with where they go, and labeled their counterparts on the frame as well.



It's amazing how light a motorcycle is without it's engine. weird.

 

[tom203]

What fun! In this attached pic, what looks like one shaft is actually a shaft within a shaft- only time they lock up is in 5th. Bad bearing or bent shaft could cause unpleasant vibration at high engine revs no matter what gear you're in.
This pic is from current ebay seller- he's had 650 trans parts for looong time!

 

[William Groebe]

Thanks for the heads up on parts, tom203. I'm going to put together quite the shopping list once I get the engine open.

 

[William Groebe]

I've been busy with work and haven't had a chance to move forward with the engine teardown until yesterday morning. My son helped me lift the engine up onto the worktable. Thanks, boy. I've been taking pictures and taking notes as I take everything off. Man, this is a slow process.

I took off the cylinder head cover and its gasket.




Removed the camshafts


Removed the cylinder head and block. Boy, is this a dirty engine or what?




I removed the pistons.

The gasket between the block and crankcase was decaying and dropped a lot o crumbs and what-not down into the engine. That's not good.


I removed the signal generator assembly and advance governor.

 

[William Groebe]

I removed the clutch cover. It took 10 minutes of rubber hammering before it finally came loose.


To remove the clutch spring mounting bolts I had to put the advance governor back on and hold it steady with a wrench while I took to the clutch sprig mounting bolts with another wrench. Then I pulled out the clutch plates making sure to keep them in order.



I flattened the clutch sleeve hub nut lock washer, but the mounting nut is on real tight and I can't get it off. I sprayed it with Liquid Wrench and will try again later.


In the meantime, I removed the starter, the gear position indicator switch, and removed the generator cover. Though the rotor securing bolt is on really tight and I can't get that one off either, so I sprayed it, and am waiting to try again.


Also, I can't understand the next step of the manual. It says to Install rotor remover attachment and sliding hammer assembly into the boss of the rotor and remove rotor with starter clutch assembly while sliding the remover. Is there some other way to do this without the special rotor remover shaft and attachment?


If anyone's got any feedback, or other ideas on how to remove those nuts, let me know. Thanks.

I probably will wait until tomorrow night to get back to work on it.

 

[tom203]

Impact wrench for both the clutch nut and the rotor nut. Once you remove the rotor nut, you need a bolt (or buy the $10 tool) that threads into the rotor hub (16mm?) ,so as you tighten it ,it pushes against crankshaft end and "pops" rotor off. Impact wrench will come in handy here too, as crank will want to turn if you try with just a regular wrench.
What fun, hats off to your perserverance.

 

[William Groebe]

I can't get the clutch sleeve hub nut off. Looks like I'm going to have to buy the clutch sleeve hub mounting nut remover tool. And I'm going to have to buy the tool to remove the rotor also. I'm going to have to put this engine back together at some point, so I might as well get the proper tools now.

Time to do some research.

 

[1948man]

You might get an electric impact wrench at Harbor Freight for not much more than the nut remover tool. It took my clutch nut off.

 

[Big T]

There's no reason to remove the rotor unless you're checking the starter clutch

 

[tom203]

There's no reason to remove the rotor unless you're checking the starter clutch

Or bored,or dismantling engine to repair !

 

[barnbiketom]

There's no reason to remove the rotor unless you're checking the starter clutch

+1... leave it on, split the cases
better yet. get another orphan bike/engine and put that on then ride it. summer is ending!!

 

[William Groebe]

Crankcase cracked.

Crankcase cracked.

Well, the case is officially open.


And BigT was right. There was no need to take the flywheel out, so I just left it there. I'd never cracked open an engine before, so I was just following the service manual instructions step by step until I realized that there weren't any case bolts behind the flywheel. No need to remove it then.

Without a clutch holder I had come to terms with the fact that I was going to have to order one from Motion Pro and wait a week or so, but my local motorcycle shop offered to sell me theirs. Sweet. Thanks, Motopia Marin.


I'd bought an impact Wrench from Harbor Freight, but didn't even need to use it. Just the clutch holder and a wrench with a 1-1/4" socket. Pulled of the sleeve.


Then removed the driven gear.


Removed the oil pump.


After taking out the gear shift shaft I got to work on the upper case bolts. Made myself a nice little cardboard template.

 

[William Groebe]

Then I did the same for the oil pan.




Then it was time to remove the lower case bolts.



A little rubber hammer hitting and viola!



Before even taking anything out I noticed some pretty deep gouging on one of the forks. Could this be part of my 2nd gear slippage problem?

 

[William Groebe]

I pulled out the neutral stopper housing, spring, and housing.


Then I removed the gearshaft camdrive and pawl screws. I removed the little cam stopper spring and it flew off. I found it, but didn't take a pic of where it was connected to the gear shifting fork shaft before removing it. I'll have to figure that one out later. It look slike it was connected to the little widget thingie on the same shaft as the single fork. I pulled out the gear shifting cam and here's the little pieces I've got.


Whoops. I handled the gear shifting cam and some pieces fell off the end of it. I didn't see how it was put together before it all sprung apart.



Looks like there are little springs inside the shaft end that push against little rods that hold little shims in place. The rods each have a flat end and a curved end. I assume the flat end pushes against the shims and the round end against the springs. Shout out if I got that wrong. I can't find any info in the service manual about this part.


Examining the gear shifting cam there seem to be some gouges in the corners. I need to do aome more research on how the gear shifting cam works. I don't even know which gear position is which. I'm looking for problems with 2nd gear, but want to fix any problem I can while in here. Here's what one of the gouged corners looks like.


Here's another smaller gouged corner. EDIT** Turns out this is what a corner is supposed to look like. Flattened like this.

 

[William Groebe]

My brain is fried, and my body is fried from sweating in the garage all day. It was a scorcher here in Marin. I'm going to take apart the gear assemblies tomorrow and check the gear dogs and teeth. Here's what they look like now. I can't see any visible damage, so I assume it'll show up once I get them separated. Unless it really only is the shifter fork and gear shifting cam gouges.




So my little issues are...

Do I need a new gear shift cam? Are the gouges bad enough that I should order a replacement?
I need to order at least one shifting fork to replace the gouged one.
Am I right in thinking that I put the gear shift cam head assembly back together with the little posts flat ends toward the shims and round ends toward the springs?
Where does the little cam stopper spring attach to on the fork shifter shaft? I unhooked it from the bottom of the crankcase and didn't check where it had been connected on the other side.

Thanks to anyone for any feedback. I am having fun with this little project, though I'd like to order myself my replacement parts and get back on two wheels as soon as possible. My truck is no substitute for my GS.

 

[barnbiketom]

nice work!! and really nice pics...we need to REALLY LOOK at the gear dogs and mating surfaces/shaft? for second tho.. I think you will find that instead of the dogs being nice and square with perpendicular surfaces, the ones for second gear engagement will be rounded and SLOPED.
the shift fork is bad too and looks like the bike had someone power shifting it repeatedly!
the shift drum too, now that I look at it, looks like excessive force on the shifter(power shifting?) or maybe the PO dumped the bike and the shifter slammed into something??
or a combination of all the above

 

[Guest]

Wow, MR Groebe, this is what I may be facing shortly (not a shifting issue, but a strip-down), so this excellent thread is a VERY welcome addition to the OEM
printed material. OUTSTANDING contribution!