Gearbox problem, will not upshift beyond 2nd

Trying to get 3rd and 4th with no avail on a static test (engine not running). No clicks, nothing. This is after i replaced the pawl and layshaft bearing.
Does this sound like a spring install issue or cam plate issue?

If neither the engine nor back wheel (and thus gearbox shafts gears etc) are spinning, then the gearbox may not want to change gears at all !
This doesn't actually prove anything, its what happens with the engine running that counts...

Turn the back wheel over while you are doing this, and see where this goes.
hopethishelps.

Possible cause,
Item number 4 may be upside down. Totally common error.
gearshift pawl spring
http://www.oldbritts.com/1972_g6.html

Thanks Pete,
That spring was the one part I had my doubts on as to orientation.
Will reverse the spring and see if that solves the problem.
Next time, I will run through ALL the gears before fully buttoning up the cover, clutch cable and putting oil in.
Would have saved a lot of time and mess had I done that.

Some good tips here:

gearbox-assembly-problem-t23957.html

probably pawl a bit too large or spring incorrectly fitted (pawl not loose or spring upside down)
http://i583.photobucket.com/albums/ss27 ... 011001.jpg

Wrong photo? As that's the kickstart pawl.

lynxnsu said:

probably pawl a bit too large or spring incorrectly fitted (pawl not loose or spring upside down)

Click to expand...

https://www.oldbritts.com/gearbox_a.html

Well, I dissasembled the outer cover to determine the spring was in the correct position with the angle on the bottom.

When putting on the cover, the manual says to hold the mechanism with your thumb through the filler hole.

Box is in neutral.
Does this photo show the correct position the pawl needs to be held in for neutral?



My spring does not touch the pawl but the ends both touch the vertical plate.

elefantrider said:

When putting on the cover, the manual says to hold the mechanism with your thumb through the filler hole.

Click to expand...

What it says (in D11,2) is: "......retain the ratchet spring in the central position with the index finger of the right hand and guide the case over the kickstart shaft with the thumb of the left hand engaged through the filler cap hole".


Edit: If you followed the procedure given in the manual, then the 'ratchet plate' will have been fitted to the inner cover (see manual, Fig D8) not outer as shown in that Old Britts photo, which is why it's often necessary to hold the coiled end of the spring in position until the cover has been pushed far enough home for the ratchet spring to locate over the ratchet plate spindle.
Which gear it is in shouldn't matter.

Took the cover off, inspected the spring. Bend is installed on lower half, spring does not touch pawl. Reinstalled cover. Same problem as before. Shifts fine in 1st, 2nd, Neutral. Still cannot get 3rd or 4th gear. Rocking motor back and forth in gear.


Could this be a cam issue if I can still get 1st, 2nd & Neutral?

Will take the outer cover back off and see if I can get 3rd and 4th by moving the quadrant manually.

I had a similar problem after rebuilding my gearbox a few years ago.
IIRC it worked ok in a static test (with back wheel spun), but on the road it didn't want to shift.
I had the cover off several times, triple checked everything, found nothing wrong.

Then on one last check (you stop looking after you find something don't you), I just happened to notice that the concave surface of the (new) pawl had a shiny mark on it.

It had been rubbing on the ratchet plate as the gearlever returned to its "neutral" position after making a gearshift, thereby dragging the ratchet plate back a little.
When trying to make the next shift, the pawl would miss the next tooth on the ratchet plate because it was out of position.

I solved it by grinding a small amount off the concave face of the pawl. I had bought 2 new pawls when ordering parts for the rebuild. They're cheap and plentiful so I had a backup if it didn't work. But it did work. That was all it took to make it shift perfectly.
You can test for this by just taking the outer cover off (again!) and watch what happens as you move the gearlever.

Remember, there's a big shimming washer in there somewhere, that has to be right, too.

One more time. Took cover off, noticed the quadrant lever was in like a 3rd gear position. It was a false neutral! Cycled through the gears with a screwdriver. All 4 there. Put the quadrant down to neutral, then put the cover back on. All 4 gears now through the shift lever.

In this case, the quadrant needed to be in neutral position (one up from bottom) when you put the cover on.

Now time to deal with a sticking clutch!!!!

elefantrider said:

In this case, the quadrant needed to be in neutral position (one up from bottom) when you put the cover on.

Click to expand...

It shouldn't really (and it doesn't specify that in the manual) as the pawl mechanism returns to the same start position after each operation, as you said that the "box is in neutral" the first time yet it didn't work then. The fact that it was found to be stuck between gears suggests the shafts probably hadn't been turned enough for the 3rd (and then 4th) gear dogs to engage.

Sorry i missed the thread. Some clutch problems can be caused by a loos nut on the r/h end of the mainshaft behind the clutch throw out lever. There is no way of locking the nut to the shaft apart from loctite. If that nut comes loose, it can turn into a bush and throw metal filings through the gearbox [ it happened on my 850 ]. I thoroughly recomend anyone who doesnt know the history of their gesarbox, the check this out if ever the outer cover on the gearbox is removed.
Dereck