Transmission woes

[DavePlum]

Bought this 80SG project bike back in April and have been working on slowly bringing it back to life. Finally got t to run and idle but now I find it won't shift into any gear except first (and back to neutral). Apparently the clutch isn't really doing it's job because when I put the bike into first and let out the clutch without giving it any throttle it doesn't stall and as soon as I put it into first with the clutch pulled in the rear wheel begins to spin. The worst part is as soon as I put it into first it makes this horrible metal on metal sound as the rear wheel turns AND the rear wheel doesn't respond to throttle. To me it sounds like the drive shaft is wobbling around inside the swing joint tube but I'm far from being a mechanic. I haven't checked anything yet, thought I come here and perhaps get some advice and initial direction. Thanks

[3Phase]

Ask before grinding the poor bike to oblivion -- good plan, Dave!

It sounds like one of those multiple problem situations, those are always fun. You may have stripped drive shaft splines, u-joint, or a bad final drive along with a shift lever that's out of adjustment.

For the drive line noise, put the bike on the center stand and with the engine OFF, spin the rear wheel forward and backward by hand with the transmission in Neutral, then listen to the middle drive, swingarm, and final drive.

If that doesn't let you know where to look next, put the bike in 1st gear and try to turn the rear wheel again. The wheel should rotate freely for a little bit, then stop when it takes up the slack in the drive line. Do it again and try to put some oomph into it after the slack is taken up to see if it will rotate the transmission and the engine or if it 'skips'.

For the transmission shift problem and metallic noise, take off the shifter cover and check the two stamped alignment dots on the shifter 'gear' teeth. If they line up, try to put the transmission in 2nd gear to see if the index marks on the shift pawl and shift drum line up. Here's forum thread with the same problem and links to another thread with pictures:-

XS11.com Forums > Idle Talk Forum > XS11/XJ11 Discussion
Shifting Issues by lakecountrydave

[Radioguylogs]

A couple more thoughts

Won't shift above 1st gear

What Scott said.....except it seems you might not be able to shift into second gear to check the "index marks" alignment.

When you open the shift linkage cover, also look at the pins on the end of shift drum. When you move the shift lever to change gears, there is a pawl that grabs these pins to rotate the shift drum. It seems that some folks have a condition where the starfish shaped washer on the end of the drum is bent or broken, and the pins come out....so there is nothing for the pawl to grab onto.

Grinding sound and no solid link to rear wheel

Worn driveshaft splines are a possible culprit.

Make sure that both ends of the clutch cable are adjusted properly- so there is a little slack in the clutch at actuator under the clutch cover. If this adjustment is too tight, the clutch can't let out and grab...although it shouldn't make a grinding sound even if it was too tight.

[3Phase]

Heh, yeah, that was the "try" part.

If something like the starfish washer has bent 'legs' or a pin's dropped out of the shift drum it'll be obvious when he takes off the cover.

[Radioguylogs]

Yup

We'll wait for more info.

I had to make this meaningless post because I accidentally re-posted my previous message and I can't delete it, just change it.

[DavePlum]

For the drive line noise, put the bike on the center stand and with the engine OFF, spin the rear wheel forward and backward by hand with the transmission in Neutral, then listen to the middle drive, swingarm, and final drive.

Ok, did this and the rear wheel will turn both directions with no unusual noise.

If that doesn't let you know where to look next, put the bike in 1st gear and try to turn the rear wheel again. The wheel should rotate freely for a little bit, then stop when it takes up the slack in the drive line. Do it again and try to put some oomph into it after the slack is taken up to see if it will rotate the transmission and the engine or if it 'skips'.


When I did this the rear wheel will only rotate about 2" before it feels as if it locks up. It did the same when putting some oomph into it.

I did the clutch adjustment (both mechanism and cable) but it's the first time I had to do that and I'm not so sure about the "light touch" on the pressure plate however I can now shift to third gear. I'd like to concentrate on that metallic sound I hear when I shift into first, it sounds like it's coming from the swing joint tube so hopefully tomorrow I'll have time to pull the final drive and swing joint to inspect them.

[skids]

For the drive line noise, put the bike on the center stand and with the engine OFF, spin the rear wheel forward and backward by hand with the transmission in Neutral, then listen to the middle drive, swingarm, and final drive.

Ok, did this and the rear wheel will turn both directions with no unusual noise.

If that doesn't let you know where to look next, put the bike in 1st gear and try to turn the rear wheel again. The wheel should rotate freely for a little bit, then stop when it takes up the slack in the drive line. Do it again and try to put some oomph into it after the slack is taken up to see if it will rotate the transmission and the engine or if it 'skips'.


When I did this the rear wheel will only rotate about 2" before it feels as if it locks up. It did the same when putting some oomph into it.

I did the clutch adjustment (both mechanism and cable) but it's the first time I had to do that and I'm not so sure about the "light touch" on the pressure plate however I can now shift to third gear. I'd like to concentrate on that metallic sound I hear when I shift into first, it sounds like it's coming from the swing joint tube so hopefully tomorrow I'll have time to pull the final drive and swing joint to inspect them.

You might want to check the U-joint while you're at it. Also (less likely to everything else) the spider gears that are covered by the plastic at the rear wheel can jet jammed with very hard grease. It should be cleaned out and new grease applied.

[DavePlum]

You might want to check the U-joint while you're at it. Also (less likely to everything else) the spider gears that are covered by the plastic at the rear wheel can jet jammed with very hard grease. It should be cleaned out and new grease applied.

Those items are on the to-do list for tomorrow morning...before it gets too hot in the garage.

[DavePlum]

Pulled the final drive and swing arm this morning. Splines, drive shaft, and u joint all appear to be fine, nothing looks stripped out or unusual other than it's definitely due to be greased again.
Started the bike and once it's in gear there's a clanking sound (sounds like it's coming from middle drive) I did notice the sound is not nearly as pronounced as when the swing joint and final drive was still on. Couple questions:

#1 When I put the bike in 1st gear, the middle gear flange immediately begins to slowly rotate, is it suppose to rotate with the clutch held in? It doesn't rotate with very much torque as I can put slight pressure on it and it will stop rotating so perhaps that's normal?

#2 I have another middle drive from a parts bike, should I just swap out the middle drive and see if that solves the problem?

Thanks for the help guys.

[motoman]

Pulled the final drive and swing arm this morning. Splines, drive shaft, and u joint all appear to be fine, nothing looks stripped out or unusual other than it's definitely due to be greased again.
Started the bike and once it's in gear there's a clanking sound (sounds like it's coming from middle drive) I did notice the sound is not nearly as pronounced as when the swing joint and final drive was still on. Couple questions:

#1 When I put the bike in 1st gear, the middle gear flange immediately begins to slowly rotate, is it suppose to rotate with the clutch held in? It doesn't rotate with very much torque as I can put slight pressure on it and it will stop rotating so perhaps that's normal?

#2 I have another middle drive from a parts bike, should I just swap out the middle gear and see if that solves the problem?

Thanks for the help guys.

That is just from the initial slack in components.
#1 if on centerstand with rear wheel off ground, that is just the clutch disc and plates dragging a bit.....no issue.
#2 not necessary,.... unless you just really like turning wrenches.

[skids]

#1 When I put the bike in 1st gear, the middle gear flange immediately begins to slowly rotate, is it suppose to rotate with the clutch held in? It doesn't rotate with very much torque as I can put slight pressure on it and it will stop rotating so perhaps that's normal?
#2 I have another middle drive from a parts bike, should I just swap out the middle drive and see if that solves the problem?

#1. Middle gear flange rotating? OK, I guess you removed the drive shaft and are looking at rotation. I agree with Brant.
#2. If the middle gear is bad, it will leak out of the seal (fixable), or lock-up. There is also a chance that someone has monkied with the shims, making the contact surface change, but I would think that something like that would cause abnormal wear.
If the issues described are not from the middle drive, and not from the final drive or the U-joint, I would suspect that the dreaded dog/slots in the transmission are an issue. As I understand it (nerver had that problem) it sounds like "clackity-clack" when you shift to the damaged gear(s) under load. If it is more of a vibrational issue, it is likely something else. Hope this helps...

[TopCatGr58]

Hey Dave,

The more you talk and describe the sounds, the more it sounds like what some folks have experienced with the "C-clip has come off of the shift fork shaft that holds the oil pump drive gear on the other end of the fork shaft BEHIND the clutch basket on the other side of the engine away from the shift side. Either that or also the large headed BOLT that secures the gears countershaft in place, it also sits behind the clutch basket, and can come loose and grind against the clutch basket!?

Good luck investigating.

T.C.

[DavePlum]

Skids- Who is Brant? Is that motoman?
Sounds as if swapping out the middle drive is likely a waste of my time.
“I would suspect that the dreaded dog/slots in the transmission are an issue”
You might be right but I’d really like to rule everything else out before attempting something like that.

Actually, I was wrong when I stated the flange begins to rotate as soon as I put it into first gear. I meant to say the flange immediately begins to rotate when I start the bike in neutral and will continue to rotate even when I pull the clutch handle in. When I shift into first the rotation of the flange continues and that's when I hear the "clackity-clack". Btw...after repeating the clutch adjustment it seems to shift into all gears fine now but I still get the "clackity-clack" in every gear and it’s not momentary… it’s continuous.

TC- I was debating pulling the clutch basket because this bike sat for at least 2 years before I got bought it so checking the clutch and friction plates might be a good idea? If I did this I could check the c clip and that large bolt. I was reading up on pulling the clutch basket, sounds like it requires an impact driver to get that center bolt off?
Thanks

[DavePlum]

There's a thread titled "Knocking in transmission (with video)" that was posted on 3-4-15 by member "oakback" that shows the exact thing my bike is doing. When he shifts into 2nd gear at the 20 sec mark...that's what my bike sounds like. Unfortunately, there's no follow up to his thread that identifies what the cause of this is. I'd include the link to his thread if I knew how.
Some people were telling him because it was on the center stand it was play in the drive line.
Going back out to the garage to clean and re-grease all the splines on drive shaft, final drive, etc and put it back together.
Also, shouldn’t I be able to shift gears without the engine running? I tried last night and it wouldn’t go down into first or up to second. Thanks

[DiverRay]

Without the engine running you probably need to rotate the rear tire to shift into all the gears. Remember, you are lining up the dogs in ALL the gears, and they do NOT match up through the range.
As long as it's on the center stand, pull the oil pan! You can look for circlips and other bits that may give a much better clue, and it's not that bad to clean the surface and put back together with the Yamabond instead of a gasket.