Re: S1 Gearbox 4 speed problem - Third gear jump
Posted: 07 Jan 2024, 19:34
Of course the selector parts on the outside have to be checked and fixed. Don't give up on the slider too soon!!! Everything overlooked on the inside is heavily punished as the thing has to be taken apart again.
The story is that the job of the navigator of Sandro Munari was to hold the gear in 3rd (in the days of the 1.2HF and 1.3HF). On the 1.6HF Lancia put a short stick which was mounted upright.
In the parts book I have I see that the slider for 3 and 4 comes from the 815.000 which is the first Flavia. That one has column shift. The problem does not occur on the cars with column shift. There is no long stick hanging from the mechanism under an angle. It is very well possible that early sliders did not have the back cut on the teeth inside the slider for the 3rd. I recommend to actually check the teeth for the 3rd for the back cut on all the teeth. To the untrained eye it looks like wear. If in doubt, buy a new slider. Same for the springs and balls inside the sliders and the fork mechanisms. They are available at acceptable cost.
Did you replace the bronze bushes for the yoke at the top? Don't forget those. Are the forks straight? Are all the clearances indicated in the book correct?
On the outside, do everything. If you really really want a perfectly shifting gearbox also put bronze bushes in the aluminium piece holding the small shaft with the hammer at the yoke end. The yoke has two wings at the top which function as anvils for the hammer at the end of the shaft. They often have one or two dents. Fill them by welding steel on them and grind them for minimal clearance with the hammer.
The story is that the job of the navigator of Sandro Munari was to hold the gear in 3rd (in the days of the 1.2HF and 1.3HF). On the 1.6HF Lancia put a short stick which was mounted upright.
In the parts book I have I see that the slider for 3 and 4 comes from the 815.000 which is the first Flavia. That one has column shift. The problem does not occur on the cars with column shift. There is no long stick hanging from the mechanism under an angle. It is very well possible that early sliders did not have the back cut on the teeth inside the slider for the 3rd. I recommend to actually check the teeth for the 3rd for the back cut on all the teeth. To the untrained eye it looks like wear. If in doubt, buy a new slider. Same for the springs and balls inside the sliders and the fork mechanisms. They are available at acceptable cost.
Did you replace the bronze bushes for the yoke at the top? Don't forget those. Are the forks straight? Are all the clearances indicated in the book correct?
On the outside, do everything. If you really really want a perfectly shifting gearbox also put bronze bushes in the aluminium piece holding the small shaft with the hammer at the yoke end. The yoke has two wings at the top which function as anvils for the hammer at the end of the shaft. They often have one or two dents. Fill them by welding steel on them and grind them for minimal clearance with the hammer.