Just about to give up with this thing now.......
Last had it running and reverse worked.

Skudderfish very kindly gave me a replacement carb and it idles much better.
Was going to try to test it in the field and went to select reverse and can't find it

1-5 all work ok but reverse has just gone into thin air.

Will I ever get this thing back on the road?

What gearbox?

Have you wound the reverse light switch in, this will stop it being able to select reverse gear.

Tom

Not sure what gearbox as it was changed by previous owner before he passed away and left it to me.
All I can tell for sure is its a 5 Speed manual.
Too dirty to see any markings until I jet wash it.

Mark

Haven't done anything since i last had it running.
It's been in same spot on drive for months with me starting her over every so often trying to sort carbs etc
I've rolled her forward a bit to prevent tyre squaring though

If reverse is up and left it's an LT77, if it's below 5th, it's an R380.

Probally an LT77 as these were fitted to SD1's with carbs, R380's came later on when EFI was more common, I think they missed SD1's altogether.

As above, are you going the correct way, reverse is past 1st if you look down by the gearstick you will see some steel prongs that are the spings, make sure these are free and have a look at the detent springs and balls incase these have rusted up.

No reason for a box to lose gears sat still.

Regards Mark

Cheers, it's an lt77 then.
Can't get left of 1 and 2 at all.
Not sure where the detent thingies are?
Can they be checked with engine in situ etc

Yes, you need to google, there is a plug in the side, behind this lives a spring and ball that locates on the selector rod within the box, you can remove without risk as nothing can fall inside the box.

First thing though, have a peak under the gear lever and make sure that the springs that keep the gear lever central are free and nothing is stopping the lever moving across, maybe soak this area in WD40 in the first instance.

If the spring/ball is rusty it will stop it moving.

Regards Mark

cheers Mark

will try that one night this week and see how she looks

Thanks folks, I took it apart and the ball bearing inside is not pushing back against the spring.
So looks like I need a new part.
Cheers for all your advice