Series 3 Gearbox

[Hellspawn]

I need one of you cluey blokes to point me in the direction of someone who can talk series 3 gearboxes or hand out some advice. Yep found those online manuals posted by Phoenix but don't really show what I want to know and that's because I've done what they don't want me to do. My gearbox is a suffix A and due to my previous bad habits has broken second and third gear (flat upshifting) which were easy enough to repair.
Though this has me wondering. There is nothing holding the mainshaft firm in the casing anymore appart from thrusts at each end. When I put the overdrive on, I had to do away with the locking nut on the rear of the mainshaft due to a modification. Previous owner did a great job of chewing the dog clutch on the imput shaft of the overdrive to the point there was nothing left. I had that imput shaft welded into a one piece, yeah I know it's heat treated, so that now it would be less possible to bust it again and not likey I was paying a grand for those replacement bits or another few hundred (2 grand) for a reco overdrive.
So I shimmed the bearing under the 3/4 syncro hub to give a total float of 10thou measured at the rear of the mainshaft in the transfer case. It's just started to throw out of first and second always on overrun and mostly after long dribbles downhill in high range, low doesn't seem to affect it. The stick doesn't thrash around from power on to over run so I'm figuring end float is only just out. The manuals suggest float a lot looser but then they presume you have that lock nut to pull the shaft onto the thrusts.
What do you figure ? :roll:

[Hellspawn]

Just wanted everyone to know I fixed it my problem. Draining the gearbox oil there was evidence of brass shavings. Pulled to overdrive back off (again!) and measured the end float to compare to what I recorded before. I now had 20thou of end float. Way too much !
After disassembly the brass washers I used before to pack the bearing under the syncro had settled. So I packed another washer in against the others so there's no float and was firm to turn.
Bolted it all back up, clean oil back in and took it for a toddle. Guess what .....no more falling out of gear and no noises so it can't be too firm.
Hope this info is of use to others with busted overdrives gathering dust in the corner.
Jay

[Phoenix]

isn't it funny how sometimes the most complex problems have the simplest answers.

I had some brass flecks in the oil when I drained the gearbox oil not long after I bought the landy, always wondered where it came from. No sign of it recently, so I guess that whatever was wearing didn't have enough oil (only got about 1/2 a litre out the first time 8O )