Synchromesh Springs

[David Yat]

I've got at least one broken 3rd/4th gear synchro spring. Drives ok but need careful change down or double declutch. Removing gearbox at this stage seems like a lot of work so has anyone on the forum tried replacing via the top of the box after removing selector mechanism. I've read that it's possible but some feedback would give me confidence to try it.

[Gazzar]

I've never tried it. I'm good at fiddly repairs, but I'd be reluctant to take that on. 

You'd need very good long needle nose pliers, patience, access, and probably long strong fingers.

[simonb]

I've done this, twice. Take floor and tunnel out. Remove top cover of gearbox and remove all selectors/forks. They just wiggle out.  Be careful you don't loose the detent ball bearings.

You will need long nose pliers and some dental floss (!).

The 3rd/4th synchro is visible and the new springs can be fed in using pliers. Tie dental floss round each spring and attach the other end outside the gearbox. This saves the tedium of fishing them out through the bottom of the box when you inevitably drop them!

IIRC its easier to have the syncro in neutral, slide one end of the spring in and then flick the hub along to get the other end in. The first spring is easier than the last. 🙄

Cut the dental floss when the spring is in place.

You will need plenty of patience, but if you are lucky, it will actually take longer to get the floor out and the selector forks out. Use grease to stick the detent balls in place when you fit the top cover.

The springs seem to last a lot longer if you make slow changes 3 to 4 and back, pausing in neutral (can keep clutch depressed) before going into the other gear. Its probably quick shifts that fracture the springs.