Gear changing problem

Hi, I´m having a problem understanding how the gear changing parts located on the inside of the outer cover works. It´s a -70 Commando gearbox. I´ve had the outer and inner covers off, checked for wear, replaced the main shaft bearing in the inner cover. So far so good, but now I can´t get the gears to work properly. If I move the quadrant up and down with the outer cover off, it works ok, all gears engage as they should. But I can´t get it to work when I put the outer cover back on. If I try to engage 1:st gear, it seems that the gear lever moves to it´s end stop, but the gear doesn´t engage. I noticed, with the outer cover in my lap, that if I move the ratchet plate, it doesn´t engage the gearshift pawl. It just slide past without touching it. I´ve fiddled with the fork spring, so that is ok, just barely touches the pawl, and the pawl is spinning easy on it´s carrier. I´m probably pretty thick, ´cause I can´t understand how these parts interact :?
Tommy

fiatfan said:

I noticed, with the outer cover in my lap, that if I move the ratchet plate, it doesn´t engage the gearshift pawl. It just slide past without touching it.

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It's the pawl that moves (with the "carrier") and engages with the ratchet plate as it does so, the ratchet plate doesn't move to engage the pawl.


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

fiatfan said:

I´ve fiddled with the fork spring, so that is ok,

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Maybe not, as an incorrectly adjusted or fitted spring is often the cause of the pawl missing the ratchet plate.
Are you sure you have the cranked leg of the spring at the bottom?

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



This would be an opportune time to replace the layshaft drive-side bearing if it's still a standard 6203 ball bearing?

I´ve fiddled with the fork spring, so that is ok, just barely touches the pawl

I usually instruct my students at tech sessions that the pawl, while sitting, MUST have clearance to the spring. A captured pawl is very likely your problem. Very often the spring must be tweeked with needle nose pliers to both assure clearance AND hold/restrain it's static positioning parallel to the arc of the ratchet plate.

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L.A.B. said:

........This would be an opportune time to replace the layshaft drive-side bearing if it's still a standard 6203 ball bearing?

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+1.....I know it's kind of off topic but it is important, and.it's possible that a previous owner has already done this , but you won't know for sure until you have a look at it yourself.

Ok, thanks all for clarifying this, I have probably misread the instructions from "oldbritts". The spring sits with the bent leg down, but I´ll get on those legs with some pliers and make some space to the pawl. About the bearing, that´ll have to wait until this winter, I´ll probably have everything out of the frame for a thorough check-up. It´s not much driving time left here, getting colder already, I´m getting older and more comfortable, so there will be plenty time for that check-up!

Maybe this had something to do with the problem? I´ll put the new spring in and see if it works better. About time, right? :wink:
Tommy