Out it comes again.
Even the most experienced of us are still only human, hopefully have all the gears again when you get the box back 
Yeah to be fair he is in his 80’s and retired, working from his home garage for the odd friend like me. I think he just likes having me visit lol.
Got it back. Refitted it, 2.5 weeks after crushing the end off my finger in a log splitter (doh). It wasnt easy but I got it in.
Reverse - fine
1st gear - fine
2nd gear - fine (phew)
3rd gear - fine
4th gear - fine
5th gear - not fine 
No 5th. Exact same symptoms as 2nd, just with 5th. Absolutely fuming.
Back out again, did I mention ABSOLUTELY FUMING?!
To be fair, if I was forced to choose I think I’d rather have 2nd instead of 5th! lol….
Both shouldnt be too much to ask for…
Did you try it on the bench before fitting?? That’s an odd fault a total refusal, if that’s what it was doing. Faults can occur in pairs as they are located/work, like 1st/2nd or 3rd 4th. If it was original it should be a UN1 13, one of the most desireable, with the long final drive and the closest ratios on a Family 3 box (which is not that close) and was used on the works maxi 5’s on both 369 and UN1.
These were underrated in their day
Dave funny how it’s lost gears diagonally opposite, could it be a linkage issue???
Correct it is a UN1-13. I went through the gears on the lever but its hard to tell, it felt OK but when you try the gear on the gearstick it just doesnt go and grates the gear when you bring the clutch up…so its close but just not quite going in.
I’ve dropped it to another mate now thats got good experience with the UN1, UN7 and 369, he’s just built himself a Quadra box and removed the viscous coupling for a torsen thingy and fitted an LSD too. Very interesting stuff and a very clever guy.
Fingers crossed Steve cos if he can’t fix it i’ll be grovelling to you for help lol
What was found to be the fault when you didn’t have second?
Could it be a similar problem now with 5th gear/hub/selector assembly?
He didnt find anything (worryingly), he stripped it, rebuilt it with a few different components and said it was OK. Hence me not going back again. I just want the bloody thing to work!
I’ve got a worrying feeling about the linkage. It’s a circle of gears thing perhaps. Especially given it’s picking up and not fully engaging. You have gone from not getting full travel at 7 o’clock to not getting full travel at 2 o’clock
Its not linkage, I disconnected it under the car and actuated the lever by hand with my lad in the car…same shizzle. Both times, out of desperation.
At least you did check. That should definitely be ruled out then . Could be a blocker bar spring. At least being 5th only the end needs to come off.
So an extra ball was found in the 5th gear detent ball and spring setup.
OK - fine. Box back in again
Quick selector rod refurb as the bushes were pretty crap
Connected up the minimum and tried it, slots into 5th. Win! - or so I thought. Rebuilt basically everything save putting the wheels on.
Listen and tell me when you know. You’ll need sound.
Racked off level = 4,975,490 / 10
Fancy giving it a go Steve? Stuck for options now.
I’ll speak to Rob tomorrow show him the video and see if he has any ideas or knows someone that knows these boxes.
Gees, that is stressful after so much work, Dave. I thought trying to fix a prop wobble / or diff connection was a mind bender on my old Audi Q.
Did the guy not tell you he’d made 5th straight cut 
Having 2 balls and a spring in the Detent hole was probably the non select fault, easy to do if you get distracted at the wrong moment, and will effectively lock it in or out of gear as the spring will be coilbound with the ball in the detent, no chance it is retracting to allow movement.
A warning to all of us, is to physically check you get all the gears on the bench before fitting, The irony would be it could have been checked in the car and repaired in situ. Definitely one to learn from.
HOWEVER. The noise can really only be coming from the 5th gear pair, It’s quiet in all the other gears, meaning all the bearings and gears are ok, just 5th pair and only when transmitting drive, they are quiet when idling round when the box is in any other gear.
One gear is fixed to the shaft, so that should be OK, for any unwanted movement, the other runs on a needle bearing, so it’s possibly worn, but highly unusual. Leaving the gear teeth themselves.
If it’s 4 wheels away from a road test, I would try it, mainly to see if it is only noisy on drive, or is it on coast also.
@Andyquadra joked about it being straight cut, but it covers what is being heard here.
I’m sitting here racking my brains trying to remember if it’s possible to fix the fixed gear backwards, I’ll need to dig a pair out and see. If it can then it has mixed the coast and drive faces up. It should be noisy on both drive and coast.
That’s as far as my thinking takes me.
Paging @Wheelers Workshop Have you got any ideas Dave???
Re-read post #76…