Re-engineering the Shift Spring

[Lucky Phil]

59 minutes ago, Bobman said:

Ok...so I decided to stick the spare stock spring in for now and will switch out for the super spring later.

I striped it and put in the new spring no problem. My question is with regard to reassembly. Remember my bike was stuck in first gear so it's tough to know where things should be for the box to be in neutral prior to refitting. I'm pretty sure I got the shifter wheels right as it seems neutral is just one 'notch' back from the dot markers on them that I think corresspond to first.

I think I found neutral in the box by messing around and dry fitting the cover and checking the back wheel moves freely.

Then removed it again and refitted with gasket maker. Before I fill with oil I thought I'd check if I can shift through gears but seems I can only select first and neutral. However I think that this is all you can get in the box without the engine running...is this correct or is it possible I have the shifter arms incorrectly positioned?

Thanks

You will probably only be able to get 1st and neutral without turning the back wheel to line up the dogs on the gears and drive sleeves. Find the neutral position on the selector assy and move all the drive sleeves in the gearbox to the mid position between the gears and dry fit the cover and make sure it seats. Then carefully remove and apply sealant and install. make sure the cover seats by hand, don't use the screws to "pull it into the seated position" 

Read this.

Ciao

[Bobman]

Argh....this is becoming infuriating!...feels like it should be a simple job but alas no!

 

So following my post above I felt that all seemed good so went ahead and filled up with trans oil and reassembled starter etc. Quickly grabbed my helmet for a run round the block to check. But I could only select 1st and neutral (note neutral light works correctly).

 

So back apart again. Figured I must have the selector arms in the wrong position when I put the cover on. However it seems there really is only one position that will allows the cover to fit. I made a little foam jig so I would know where that is....seems the top and bottom arms need to be in the same position...15mm from the inside face of the case to the centre of the pins. Is it possible to fit the cover with the dogs/arms in the wrong location? (Anyone have measurements or diagram of the right position for neutral?).

 

So dry fitted the cover again but spinning the back wheel can only get first and neutral.

 

Is it possible to fit the spring incorrectly and have this effect?...seems to be fitted right but its the only thing that's been changed. I tried shifting the mechanism through the gears with the cover off the bike using vice grips and it appears to work just fine?

 

The linkage has not been changed at all and is fitted in the same location on the spines (marked it before removing).

 

Grateful of any tips/advice.

 

Thanks

[MartyNZ]

Here is what my gears looked like when in neutral.

I hope this helps.

[O2 V11]

It has been a while since I have had my cover off but from memory there is only one position that the 4 dowels can be in for the cover to fit correctly. I got it wrong once and cracked my cover by tightening it up with the dowels incorrectly aligned.

If you still have your cover on the bike have a close look at your gear linkages on the up shift. Make sure nothing is binding preventing the up shift, the starter is really close to the linkages. Hopefully you only have one of the connecting fittings reversed and it is catching on the starter, preventing an up shift past neutral.

Rob

[MartyNZ]

And here is a picture of the selector cam wheels set to neutral. Note that the yellow marks align when in first gear.

[MartyNZ]

14 minutes ago, O2 V11 said:

It has been a while since I have had my cover off but from memory there is only one position that the 4 dowels can be in for the cover to fit correctly. I got it wrong once and cracked my cover by tightening it up with the dowels incorrectly aligned.

If you still have your cover on the bike have a close look at your gear linkages on the up shift. Make sure nothing is binding preventing the up shift, the starter is really close to the linkages. Hopefully you only have one of the connecting fittings reversed and it is catching on the starter, preventing an up shift past neutral.

Rob

That could be it Rob!

[MartyNZ]

While we are looking at the gearbox selector mechanism, here is a reminder of some collected wisdom about the selector pawl arm and its troublesome spring.

[k99]

I was in a similar situation.  Turned out that the cam gears on the gearbox cover assembly were off by one tooth.  I could only get to first and second gear. The divot for the neutral sensor was close enough that the neutral light still worked.  

I originally drew lines on the cam gears to mark neutral but they might have been rubbed off during reassembly.  I then noticed a dimple on each cam gear that marked 1st gear so I lined those up to fix the problem.  MartyNZ has a good picture of his above, but certain versions might not have those built in dimples.

Also, it's a good idea to check each of the wire springs in the cover assembly.  They have very specific routings and can fall out of place.  And don't forget about the two stop plates that prevent shifting beyond 1st and 6th gears.  Those can fall out of place too.  Once you have the cover assembly back together turn the large cam gears by hand and look carefully how everything moves from 1st through 6th gear.

Do a test fitting before adding fluids and sealing everything back up.  The cover should go on without force, just a little jiggling to work it into place.  With the rear wheel off the ground you can turn it and shift through all the gears.  The engine does not need to be running.

[Bobman]

Thanks very much gents for all your input.

 

To summarise

 

- pretty sure I assembled the mechanism with the dots aligned (1st gear) but will double check later in case it's a tooth out. The photo is with the mechanism shifted one indent to what I believe is neutral and the position when reinstalling the plate. Note the silver marks on the cogs are from when I put a blob of gasket maker on the pins to help me figure out where they should be to engage the slots. There seems to be lines drawn on the cogs by a previous owner or mechanic that appear to correspond to what I think second gear?

 

- each of the dogs/shifter pins were moved to ±15mm from inside face of case to centre of pin (see my foam jig below) which seems to be the only way that the cover will fit. I'm assuming this is neutral and back wheel spins when off the ground which seems to confirm this? Though it's hard to be sure it appears to be similar to the picture MartyNZ provided.

 

- no force other than slight wiggling needed to fit the plate and its fully seated before any bolting.

 

- dry fitting the plate with a couple of hand tightened bolts and re-installing the linkage can only select neutral & first (while manipulating the back wheel). The linkage is not fouling on the starter cause it's not fitted yet. Pretty sure the linkage is exactly the same as when originally removed, I only took off the arm from the shaft nothing else, but I will double check later.

 

- I did check the spigot dimension when disassembled and it was 15mm.

 

- I intend to replace the stock spring that I am currently installing with a super spring at a later date once I have gotten hold of one.

 

Logic seems to point to some issue with my installation and reassembly of the spring & mechanism. However as I pointed out before the mechanism does seem to shift properly through all seven positions (1-N-2-3-4-5-6) when off the bike.

[Lucky Phil]

So you have aligned the dots on the gear wheels and then shifted the mechanism into neutral to fit? It's hard to see on your low res image but it looks to be a tooth out to me.

Ciao

[docc]

39 minutes ago, Lucky Phil said:

So you have aligned the dots on the gear wheels and then shifted the mechanism into neutral to fit? It's hard to see on your low res image but it looks to be a tooth out to me.

Ciao

Agreed.

[Tomchri]

Sounds like that other big spring is not correctly installed, ask how I now. Goes easy thru all gears with the plate in your hand. Only first, and neutral on the bike. Just my suqestion.

Cheers Tom.

[Bobman]

Tomchri....sounds exactly like my symptoms. That will be my first check. Thanks

[docc]

5 minutes ago, Bobman said:

Tomchri....sounds exactly like my symptoms. That will be my first check. Thanks

Of the two other springs, are we speaking of the asymmetrical "indexer" spring or the symmetrical "centering" spring?

Otherwise, I would certainly address this alignment first:

 

 

[Tomchri]

Wasn't paying enough attention when took it apart, a spring here and a spring here, what coud go wrong , so hopefully.

Cheers Tom.