4 speed all synchro box with remote gear change won't fully engage reverse.
Would adjusting the knuckle position on the end of the remote make any difference? If not
what can I do to solve it?

Has this got worse over time or is it a fresh rebuild?

This is a fresh rebuild of engine and gearbox meticulously done by the owner who sadly died and was unable to test it. I have taken it over and installed the complete subframe. 1st 2nd 3rd and 4th are fine but reverse will not fully engage. Could the knuckle be on the wrong spline by one or two positions?

The LH male knuckle should be horizontal when in neutral.
The gear lever should be vertical viewed from behind when in 3rd and 4th gear.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

This could be due to an overly long bolt in the diff pinion support. This is a fairly common error that will physically prevent reverse gear from fully engaging. Unfortunately it is in the bottom of the box, so only one way to definitively diagnose...

I reckon you might be able to put gearbox into reverse at the knuckle;

Pull off the exhaust and intake to then remove the knuckle.
Then refit only the male part of the knuckle back onto the gearbox and try and manually select reverse.
To select reverse you need to push the shaft all the way in, and then lift up the knuckle (in other words rotate it anti-clockwise)
You will need a to use a shifter or a bit of pipe for leverage on the knuckle

I reckon this could be done with the engine in the car, it won't be easy, and I've never actually done it

thanks for all your replies. Definitely food for thought.

try the knuckle first obviously - I put mine together recently and couldn't get 1st & 2nd once it was in the car - I was thinking the worst, except that it selected OK when I was locking up the big nuts with 1st & 4th selected... The knuckle was a spline out, yours might be out in the opposite direction. Does it feel like the stick isn't far enough to the left when selecting 1st and 2nd?

_________________
did I tell you that I won a trophy?

It feels as if it's slightly too far,

Hmm, that's not good then...

Get someone else to put it in each gear while you look down the back of the motor - you might see what's going on. It could be as simple as the bolts being slightly loose

_________________
did I tell you that I won a trophy?

Finally discovered the cause. With engine out and gearbox removed, 3 small broken pieces of a magnet had attached themselves to the mechanism and prevented reverse selection. Must have come from a magnetic retrieval tool but not whilst I've had the car. I bet that's a new cause.

More likely the magnets are from the sump plug. I never thought they would break but I have 2 broken ones here.

_________________
Cheers Dave.

Of course. Never thought of that, Dave.