Jump to content

Ossa Gearbox


mac73
 Share

Recommended Posts

Hi, hopefully someone can help.

My 2012 factory gearbox has just decided to lock up. After following the instructions I can find on the net I've removed the 5 bolts, sprocket and gear lever but it still feels solid when tapping the shaft. I don't want to tap harder in case there's something I'm missing.

Any ideas.

Link to comment
Share on other sites

 

Here is what I got from a guy that pulled his. (From ossaform.com)

http://ossaforum.com/index.php?topic=27.0

#1 - if you are pulling the tranny - IT MUST BE IN GEAR. Otherwise something very bad will happen. Not sure what, but everybody says this.

#2 - when removing the tranny make sure to remove the clutch fixer nut. This is NOT listed in the PDF from OSSA Canada. The nut is a LEFT HAND THREAD and is found inside the clutch housing. You have to hold the opposite side of the clutch fixer rod, by inserting a torx in the opposite side of the engine (ever wonder what that little breather hose is just ahead of the engine chain sprocket? it allows air to escape from the plunger of the clutch, but also allows you to insert a torx to hold the clutch fixer rod)

#3 - when pulling the clutch cover a thrust washer over the kick start will pop off and get inside the engine. If you are removing the tranny - no big deal. But if you are just removing the clutch, its best to lean the bike way over towards you so it falls on the ground, and not in the engine.

#3b - the clutch salve cylinder thrust bearing and washer will probably fall off too.

#4 - if you do anything to the tranny you will probably have to adjust the gear selector "shift spring regulator". The GasGas clutch video shows how to do this:

Edited by lotus54
Link to comment
Share on other sites

 

When we took my lads out we just took the 5 bolts out , front sprocket off, gear selector lever off and gently hit the output shaft after covering it in WD40. If you follow the instructions you can't go wrong.

As has already been mentioned ... make sure it is in gear

Link to comment
Share on other sites

 
 
  • 2 weeks later...

Just got box back from dealer.

When I tighten it fully with the five bolts it jams up. There is no spring return in the shift.

Also the sprocket shaft does not seem to be through far enough to get the circlip on. It doesn't make sense as everything else looks ok.

I must be missing something but just can't see.

Any ideas??

Link to comment
Share on other sites

 

Did the gear lever have return 'spring' before installing the gearbox?

Since you are supposed to have it I gear before removing, I assume it should be in gear before reinstalling?

Sounds like something slipped out a bit on a shaft to me- but I've never had one of those gearboxes out.

So just guessing.

Mark

Edited by lotus54
Link to comment
Share on other sites

 

Hi Mark,

The change has spring feeling until bolts are tightened. The reason for it to be in gear is to keep the spring at the bottom of the shift drum in place as its seemingly a pig to put back if it pops out. When out the box is free and selects fine.

It's like the gears ate not far enough on shaft stopping the shaft from coming through the hole.

Just wondering before having to send it all back.

Sandy

Link to comment
Share on other sites

 

Hey Mac, I replied to your post on OSSA forum:

As for the shifter not moving. One thought is the shift return spring has slipped up and forced the shifter assembly up. Then when you tighten the tranny in place, it has an extra 2-3mm on the shift drum.

Any chance you can take a picture of the shift shaft assembly on the tranny and post it?

I have posted what mine looks like with a point to the spring. "A" show the shift drum nicely sitting close to the tranny plate. "B" points to the shift return spring which can pop off the shift shaft assembly and force the drum up 2-3mm.

Link to comment
Share on other sites

 
 
  • 2 weeks later...

At last, bike back from sgs with the gearbox in and working. I had her out all day yesterday and she is amazing.

Still unsure what was wrong but I know they've removed the outer washer from the selector drum as well as a problem with selectors.

I find it hard to believe that a precision piece of equipment can vary from bike to bike, some bikes have washers and some don't?

Anyway it's fixed so I'll just enjoy it while I can.

Can't thank Ian at sgs and Duncan for their help, knowledge and effort taken to get things back to me.

Link to comment
Share on other sites

 
Hi mac73,


all the bikes have only one washer placed in between the spring (point "A" of the picture from trialtrial) and the selector drum.

I had to replace the selector drum+selector shaft last december and I had the same problem than you!


I was sure that one washer was between the spring and de drum but I didn't remember the other washer on top of the drum. But when I received the parts from my dealer, a washer was already on top of the drum. So I decided to assemble the shifter shaft with two washers, one in each side of the drum...

After wasting my time for a complete weekend trying to put back the gearbox (but having the same problem than you) I decided to ask my dealer...: the factory ships the shifter shaft + drum + SPARE washer on TOP of the drum, but it is only because it is easyer to ship the washer on top than in the lower part of the shifter shaft!
Link to comment
Share on other sites

 

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
  • Create New...