Series 3 jumping out of 1st gear

so....my S111 jumps out off 1st unless you hold it forward. I’ve stripped the top off the G/box and found the ‘potential’ culprit. It seems that the selector fork is quite worn (please see pics). Everything else is spot on but the movement I need to keep it in 1st is approx 5mm. Does anyone know where I can get a new fork or measure a spare so I can build up the metal again on the fork ends - shiny bits in pic

Thank you

Rich

It does not look too bad in pics , have you checked the detent springs and balls

Yes all dents and balls all fine, just seems like i have 5-6mm of play when i push the gear stick forward. Doesn't jump out when i do this. I saw a new one on tinter web and it had more metal of the bottom of the forks.

Rich

Check bottom of gearstick not worn.

Ahhh now thats a good point - its nice and round with a circlip on the bottom. Whats the tolerance? just make sure its round?

Thanks in advance

Would anyone have a photo of a 1st & 2nd Gear selector fork so i can see how much metal i may need to add?

Thanks

Have a read through the same problem on this forum , just search “jumping out of 1st gear “
Maybe other causes

Cheers Steve

I would have thought as long as the selector forks makes the gear engage, it is ok. Popping out of gear is usually indent springs. Have you drained the oil to see if there is any metal debris in it?

Col

Hi Col, oil is all clear - i've been living with this for nearly 2 years so might just put it all back together and live with it until i can afford a refurb unit. I was thinking of welding a bit more metal on the selector fork but cant get a picture anywhere of one.

Rich

Maybe remove detent, select gear and see if the cut out section in the selector rod is central in the detent hole?
Try new detent springs and balls, cannot be expensive, and while you are in there.

Check the rear man shaft nut is tight possible that selecting 1st is pushing gears back.
Selector forks are ground hardened steel what suffix is your gear box ?
What is the measurement of the fork end I possibly have a spare from early box I can compare measurement on.
There is some movement of fork on slector shaft you can slide it toward 1st gear and then tighten the bolt to see if that helps.

Thanks Blackburn, the measurements are approx 7mm at the end of each fork leg . Ive also noticed this morning that i'm missing 1x detent springs on the gear cluster (@Colthebrummie). I believe this may be the cause?

Thanks

Rich

So after looking at Steam Wally on YouTube I think my 1st / 2nd gets selector fork is well worn. His has two parts on the bottom of the fork that poke out but about 5mm. Think I may weld some metal back on and see how it selects

Measured a suffix D box 1st gear selector fork 7.6mm wide.

Brilliant, thank you. Yep, mines well worn so ordered a new one.

Rich

Quick update, managed to replace the synchro flat spring that was missing in situ. Used Youtube which was a great help (link below). Now waiting for me new OEM selector fork.



Rich

Impressive video, I did see a write up years ago about changing in situ, how long did it take twiddling about and did you use the 3 lots of long nosed pliers

Took me about 40 mins Steve and yes, i ordered the same pliers off Amazon

Nice one , certainly beats removing the seat box and a full strip down , thanks for putting that up