Gear box question

[Anonymous]

Gears 1-2 sound pretty good but as you go up 3-4-5 it gets louder and louder I am in fear the gear box needs a rebuild is this a hard task? Can I do it while leving the motor in the bike?

[SqDancerLynn1]

First check the chain and chain tension, Possibly the output shaft brg. Don't know if it can be changed in the bike. To get to the trans engine has to be removed and cases split

[Anonymous]

Ok do you mean the timing chain? I think all it is is a bearing or at least that is what it sounds like and after flushing the whole gear box out yesterday I observed no mettel in the oil so thats good I guess. I am going to call a couple bike shops today as this is realy not somthing I want to take on in my garage. What should I be looking at as far as a whole trainy rebuild?

[Anonymous]

Well I jsut talked to the local bike shop and he said just for him to tear into it to find out what the problem is will cost me more than the bike is worth so I guess if that is the case I will go with my original idea of selling it. Has anyone here ever rebuilt a ghear box? how hard is it? My book says it requiers special tools can anyone tell me what tools? If I am going to tear into that should I just rebuild the motor as well?

[Anonymous]

I don't think you want to rebuild the transmission, as the parts are going to be expensive. On top of that, you can't do all the work yourself, unless you have a press in your garage and some caliphers and dial indicator. It's probably best to get a used transmission from somewhere - IF it's the transmission that is making that noise.

Before you go tearing everything apart do a little investigation. Lynn suggested the output shaft - it has nothing to do with the cam chain. The output shaft is what the output sproctet is connected to. Grab the sprocket and see if you can move it - there should be no up down or side play. Put the bike in neutral and turn the sprocket - it should be smooth.

If everything checks out above, then I would take off the clutch cover and remove the clutch hub. Inspect all the the clutch components.

Now that you have the transmission disconnected from the engine. You can put the transmission in 1st and turn the sprocket again. Listen for any nosies and see that it turns smoothly. Do the same for 2nd, 3rd ....

I'm no expert - that is just what I would do to try to figure out the problem.

[Anonymous]

Swanny's plan is the right way to go about this. Just what kind of noise are you getting?

[Anonymous]

Please exuse my lack of knowledge I have never inb my life rebuild a motor or gear box in anything. The most I have done is replace the head gasket in my toyota and that even took me 5 days. How do I get ahold of the bevel gear unit to see if it shakes? I also replaced the transmition in my toyota with a junk yard one and the old trainys problem was the bearing for the idler shaft was waisted. The bike is making the same sound. The oil looked verry dirty but I saw no mettle in it. It almost sounds like its just a bad bearing in it/.

[Anonymous]

Guys, Jason's bike is a shaftie. I think he's getting confused by the sprocket comments.
Bottom line, if you're not comfortable taking it apart, it might be best to sell it now, rather than get halfway through and try to sell a bike in pieces.

[Anonymous]

Shaftie??? Jeckler, how do you know all this stuff?

Yea, it sure helps to know what we are talking about. This should have been my first question - 'What bike you got?'

[Anonymous]

Yes sorry for the confusion it is a shafty. I dont feel comforitable at all tearing it down but hey it may just be a good project. I am nitorius for geting half dont then just literaly giving my projects away LOL sure would be nice to finish one some day.

[Anonymous]

I wish I could help, but I've never had a shafty apart or even worked on one, so I am basically lost. There are others on this site who do work on their g models however. If you don't get any responses in this thread, start a new one with the word 'shaft' somewhere in the title. I bet you get their attention then.

Again, I'm ignorant on shafts, but maybe it's not the transmission at all, but the driveshaft.

[Anonymous]

While I am not familar with anything on a gas motor realy and especialy on a transmition I am fairly confident the nois is coming from the secondary gear box. I am hoping I can inspect at least the bearings with out pulling the motor. Dose anyone know if I can do this?>

[dgeorge]

Yes you can do it with out taking the motor out, but you will need to take all of the engine mounts off and jack the motor up about a 1/2 in or so if you have to pull the secondary drive gears out. Do you have the service manual for your bike? If you don't I would highly recommend getting one. The procedure for checking them would be to pull the rear wheel and swing arm, to expose the shaft, then you should be able to check the secondary driven gear bearings by turning the shaft by hand. I'm kind of thinking it may be the same problem that I had with my 1100. It wasn't the bearings it was the output shaft broken right behind the nut that holds the yolk for the drive shaft to connect to. When you get it apart let us know what you find and we can work from there OK.

[Anonymous]

"It wasn't the bearings it was the output shaft broken right behind the nut that holds the yolk for the drive shaft to connect to" Wouldnt that render the bike unridable? My bike cruzes through the gear and rides down the road great its just very loud LOL At this point I am most likly going to keep the bike but instead of being 2 tires away from cruzing I may just tear it down to a bear frame and rebuild the whole bike. I do have the repair manual for it and the past few days I have been reading all about the engine and gear box tear down. It realy dose not sound that hard "Not nearly as hard as my 81 carolla" Hate to do it though I am told with 43,000 miles the bike is barly broken in.

[dgeorge]

No the bike will still ride because the yolk is still attaced to the output shaft of the secondary drive bevel gear, but the nut ratteling around inside of the yoke will sound like bearings, the po of my bike took it to a shop and they told him that it was the u-joints in the shaft itself, but when I pulled it apart the nut fell out on the ground and I could just pull the yolk off of the output shaft. After that it wouldn't run, but by that time I knew that I had to replace both the secondary drive and driven gears.