Does anybody know if it's possible to change the first/second selector spring with the gearbox in place? I think mine's broken, when I put it in first ready to set off there is no positive action of the lever and as soon as I take my hand off the gearlever the lever promptly returns to neutral. I really don't feel like removing the engine with the present Artic conditions, maybe a bungy cord round the lever might do a temporary fix.

I fear not Dave, I'm afraid that it's a gear box out job.
J

Location: As far east in Kent as you can get

Dave,

I have only done this in situ a couple of times and it was a long time ago.

Here are my notes from 2011, practise on a spare one first!


1. Remove the gearbox/floor and flywheel covers etc.

2. Remove the rear engine bolts, loosen the front engine mounts and jack the rear of the engine up slightly.

3. Remove/loosen all of the bell housing nuts and separate the gearbox from the engine, half an inch to an inch will do.

4. Remove the top of the gearbox and the change speed gate/interlock arm.

5. Using a small hacksaw cut a screwdriver slot into the end of the far right selector rod.

6. Loosen the nut on this rod and use one of the other nuts as a locking nut against it to loosen the rod in the gearbox housing thread if necessary.

7. Using a suitable screwdriver on the freshly cut slot described in “5” to wind the selector forward until it is out of the gearbox casing.

8. Push the selector fork on this rod as far back (back of the car direction) as you can get it and place your finger over the hole so that the spring and ball don’t pop out.

9. Continue to gently drift the rod towards the flywheel until it is clear of the hole.

10. Remove the spring and ball (the latter with a magnet), replace with new.

11. Use a large screwdriver on the flyweel to push the rod back and then use the screwdriver and slot to wind the rod back into place.

12. Push the selector back into place and adjust the rod until the selector forks line up, put nut back on the rod and tighten. Replace everything you taken off etc.

Thanks Ruairidh, that is basically what I thought, although in my case I don't think item 8 will apply I suspect the hardest part will be extracting the broken spring.

Personally I'd rather take the box out and do it on the bench, just in case I dropped the ball (sic)

or the spring.

One of those jobs where Murphy's Law will more than likely apply.

Location: Gard, France 30960. Used to be Languedoc-Roussillon but now it's Occitanie

Likewise - considerably less fraught with box on the bench.

Dave you do not mention what model car you have. I can remove the gearbox from my Ruby from inside the car leaving the engine and everything else in place. Regarding temporary measures I can recal back in the early 60s people used rubber rings cut from old inner tubes to hold the gear shift in place.

John Mason.

Location: Nottinghamshire

A crafty solution. For some reason failed springs seem reasonably common.

It is a long time since I did such work and I do not want to spend time playing with a spare to check, but when tinkering with Seven boxes with the interlock removed is there any risk of popping the synchro balls, a risk with some other makes? Somewhat more irksome than a selector spring!

Location: Auckland, NZ

Been there and I have the T shirt somewhere. In a 4 speed special descending a very steep hill in Cornwall in bottom gear, when we got to the bottom the transmission was locked and the gearlever solid. Removed the top of the box and put the selector back in neutral with a borrowed big crow bar, this resulted in all the synchro balls and springs flying out. So I drained the oil and collected all the springs and balls and put the oil back in the box. We then had a lovely day on the beach, it was our honeymoon. The only way out was up the same steep hill and I soon learnt to balance the amount of power with the amount of effort to hold it in gear. It was some years before I stripped the box to refit the synchro balls & springs. This has happened to at least 2 other Sevens that I know of, I think they were both recovered home.
Did a dry run today on the bench with a spare box, as I didn't have a small enough magnet I made an electro magnet.

It's an RN saloon with a 3 speed engine & clutch and two synchro (no risk of synchro balls and springs popping out Bob)4 speed close ratio gearbox, so items 2 and 3 on Ruairidh's list don't apply. The bore of a 3 speed clutch cover plate is bigger than a 4 speed so the selector rod will slide forward till it meets the clutch centre plate leaving enough room for the job. Once the selector is moved forward for the operation a red cap was inserted into the selector to stop anything disappearing into the works. The longest part of the operation was removing the spring and being certain all the bits (7)were removed. The electro magnet removed and refitted the ball, it's power being switched off when the ball was in place so it wasn't removed again. Quite a pleasant 2 hour job in the morning sunshine.

Nice work Dave.