G50 gearbox self centering between 1st and 2nd

[dannytattersall]

Hi, I have a G50/50 gearbox fitted to an RSR replica that I have recently bought and it appears to self center between 1st and 2nd gear instead of below 3rd and 4th gear. As a result, when going back down through the gears there is an increased risk of selecting a lower gear than required. Any suggestions regarding how to resolve this would be most welcome.

Thank you in advance,

Danny.

[blue911rsr]

There are 2 springs on the internal shift gate that control that
One is bigger then the other maybe they got installed backwards
Only way to get at it is to take transmission apart

[dannobee]

Could be the springs reversed. Have you driven another car to confirm it's not normal? Do you know if the trans has ever been disassembled or overhauled?

Springs 11 and 12.

[dannytattersall]

Thank you for your replies. The gearbox has indeed been overhauled so I think you both could be correct that the springs have been fitted incorrectly. I'm not at all happy about it but it needs to be resolved to mitigate against a very expensive engine being damaged. I'll speak to the people that overhauled the gearbox and ask them if they will provide some goodwil against the cost.

Thanks again for your input,

Danny.

[dannobee]

I thought about this a little more. If they reversed the springs, it would tend to stay in the 5-R gate. More likely is that the top spring (11 in the diagram) could be missing or broke, which would allow spring 12 (the stiffer one) to push the shift lever up further, into the 1st-2nd gate.

If you look closely at the shift lever in this pic, the left tang is engaged with the 3-4 shift shaft. This is the natural neutral position. If spring 11 was missing (on the left side of the shift lever), the shift lever would move further to the left, engaging the right tang on the opposite side of the shift lever (just out of view on the right side). It would then fall into the 1-2 shift shaft.

If the springs were reversed, it would push the shift shaft to the right, engaging the tang into the reverse lever and the shift lever tang would be engaged with the 5-R shift shaft.

In any case, it appears that the trans would need to be disassembled to see what happened.

[dannytattersall]

[QUOTE=dannobee;11848720]I thought about this a little more. If they reversed the springs, it would tend to stay in the 5-R gate. More likely is that the top spring (11 in the diagram) could be missing or broke, which would allow spring 12 (the stiffer one) to push the shift lever up further, into the 1st-2nd gate.

If you look closely at the shift lever in this pic, the left tang is engaged with the 3-4 shift shaft. This is the natural neutral position. If spring 11 was missing (on the left side of the shift lever), the shift lever would move further to the left, engaging the right tang on the opposite side of the shift lever (just out of view on the right side). It would then fall into the 1-2 shift shaft.

If the springs were reversed, it would push the shift shaft to the right, engaging the tang into the reverse lever and the shift lever tang would be engaged with the 5-R shift shaft.

In any case, it appears that the trans would need to be disassembled to see what happened.

Thanks again for the information. I was hoping that this part of the selector was accessible via the end cap rather than needing to remove the nose cone. That was the impression that I got from the parts catalogue picture that you kindly provided, but the photograph appears to show that it is indeed in the nose cone section and therefore requires a more in-depth disassembly.

[dannobee]

It will require removal of the nose cone, 5th and reverse gears on both shafts, 5-R shift fork, and removal of the trans case/intermediate housing (and of course the reverse switch and pin). The big nut and little nut will need to be replaced and retorqued on assembly. If it was just overhauled, call up the shop and ask them for their opinion.

I suppose it could be something hanging up in the shifter or shift rod. But this late in the game, I assumed that those checks have already been performed.

My illustrations are out of the Workshop Manual, not the parts catalog. There is likely a difference in detail between the two.

[dannytattersall]

My next course of action is to speak to the people that completed the overhaul. I'd do it myself if it didn't require as much work as you are suggesting. Thanks once again for the advice.

All the best,

Danny.