Gearbox problem???

[muppet]

Hi guys just got but from the Bob Scott 'Kia Gravel Sprint', where the Datsuns did very well apart from my 120y which didn't even make the indian file practice run.
The problem is the gearbox is stuck in reverse when its in neutral (so can go backwards when clutch is released) but when a gear is selected and clutch released the car just stalls (stuck in gear), what should I belooking for when I take the gearbox out this week all things going good, yes the gearbox has got oil in it.

Any help would be useful, thanks Brendon.

[nissandrifter]

sounds like something has gone wrong with the reverse gear selector fork or interlock mechanism ,it stalls because its selecting two gears at once (reverse and whatever other gear you try)and locks up .put it in any forward gear and try push the car ,it will most likely not budge at all .
easy fix ,but you will have to take box out .reverse gear selector fork may be bent or the roll pin holding it to shaft sheared off ,or at gearlever end (depends on box 4 or 5 spd).or you could be just plain unlucky and the main rod from gearlever has managed to get out of the reverse shaft leaving it engaged but free to select other gears (happens when the ball on end wears down and the grooves on selector rods/shafts wear to rounded corners).before you take it out try selecting reverse and putting back into neutral.
cheers andy

[Overkill]

Chances are the selector fork roll pin has shorn off. Or you might be unlucky and the fork might be damaged. The fact that you're still able to select other gears, would suggest that the selector fork has become independant of the selector shaft.

[muppet]

Had a wee play today it it looks like I can only select 1st and 2nd I think, should be out tomorrow so might know more then.

[Overkill]

This is an "H" pattern box yeah?
The fact you're only able to get 1st and second means that the problem lies where your striker finger engages with the selector shafts. The striker finger has come out of where it connects to the rod. It may even be bent.

[muppet]

Yes it is a 60 series H pattern 5 speed. Have got the gear lever out and it looks all ok with that part.
Who would be a ble to look at the gearbox and get it recon, as it also had a problem with crunching second when down shifting, and what sort of dollar mark would this be?

[Overkill]

There is a gearbox shop here in CHCH, but I imagine they aint cheap.
The crunchyness will be sad synchro ring. Sometimes you can sway the ring off 5th gear for it as you never change down into 5th gear. but be aware that the cone which the synchro runs on can also wear. You may be able to use parts from a C20 van box to fix it.

Also, it's occoured to me that you've most likley shorn the roll pin which holds the other end of the selector rod to the end which engages with the striker finger.

[Overkill]

pm me your email addy, and I'll email you a workshop manual for a 5 spd.......