here we go...
So my procedure for installing or changing the gears in your Ford 9" centre section is:
(1) You'll need a rebuild kit, a big torque wrench and the mechanical abilty to pull it apart without instructions.
(2) Get the bits that are missing from the rebuild kit. (you won't get ring gear carrier bearings and if you have a Daytona pinion you'll need a pinion shim pack and (maybe) a heavy duty pinion bearing. Oh and the little retainer clip thingy that holds in the pinion nose bearing which you'll destroy getting it out)
(3) Assemble the pinion- this involves the infamous 'crush' sleeve (unless, like mine, you have the heavy duty 'Daytona' housing which comes with the nodular iron case fitted to Boss Mustangs etc. In this case you use a solid sleeve and shims- personally i'd bin the crush sleeve and do this anyway!) I assembled it with one shim (thickest of 5 in the kit) and slowly tightened the yoke retaining nut until the bearings got tight- not enough shim! I stripped it, added a shim and kept trying until i could tighten the nut to 200lb and still turn the pinion with slight resistance (supposed to be 8 or 30lb/inch turning resistance depending what you read...). Then i stripped it one last time, fitted the big front oil seal (remembering the flat washer behind it!), loctited the nut and wound it up to 200 one last time. Now the pinion assembly is ready to bolt into the main housing (known also as- 3rd member, pumpkin, center section, ham, diff case, chunk... does any other part of a car have so many names?)
(4) Again, it's shim time. Shims go between the pinion housing and main housing, this adjusts the pinion depth in relation to the ring gear. I guessed at the two thickest shims to start (out of about 8 of varying thicknesses).
(5) Make yourself a stand or use lumps of wood to prop up the centre section, it's time to fit the ring gear/ diff assembly. This is really fiddly cos its pretty heavy, it sits in taper bearings which will move all over the place and you have to hold all that together whilst fitting the bearing caps and the ring gear bearing adjusters in whatever order you find easiest. Once you've got it all in place and the adjusters aren't cross threaded (careful!), tighten the cap bolts so you can still turn the adjusters by hand, but only just.
(6) Now adjust the backlash by moving the ring gear side to side ( by turning one side adjuster out, then turning the other in), so it meshes closely with the pinion. (i made a tool to do this out of a short bar with 2 bolts through it) You'll get somewhere near by rocking the ring gear as you adjust it so it clonks against the pinion. A big gap and you're too far out (too much backlash), no clonk and you've none! (Check also that the ring gear isn't hitting the case around the pinion nose bearing- its a bit close here!).
(7) Once you think you're somewhere near, it's out with the marking grease. To start i just painted 3 or 4 adjacent ring gear teeth, both sides. Press a rag against the ring gear to create some drag and turn the pinion by hand so the marked teeth make contact a few times. Once you can see the wear pattern you're on the way. This is where you need one of the little charts you'll find somewhere on the net (good one here-
www.drivetrain.com/ringpinioninstal.html)
(8) The pattern is a product of the pinion depth AND the backlash- you have to get both right. You change shims for the pinion depth THEN try to adjust the backlash. If the pattern won't come right, you need to change pinion shims and try again.
(9) Once it's looking right, mark the whole ring gear and do step (7) again. The pattern has to be even all the way around, if it's not, you got a problem! Most common cause is the ring gear distorted or not properly seated on the diff housing.
(10) Take out the pinion assembly one last time and fit the large 'O' ring seal. Before refitting:
(11) Set the ring gear bearing preload- tighten the adjusters evenly until you reach the correct rolling resistance (couldn't find figures for this but- slight rolling resistance and no play) and torque the caps down. Refit pinion assembly, check your wear pattern hasn't gone off and CONGRATULATIONS!!! YOU, LIKE ME, HAVE JUST BUILT YOUR FIRST 3RD MEMBER!!!
(12) BEFORE YOU DRIVE IT PLEASE NOTE this was my 1st go, i'm not a trained mechanic, i ain't run it yet and this is just me sharing the information i've spent weeks trawling the web for and what i've learned whilst building the thing, purely in the hope that it'll make life easier for the next guy. Use your common sense- i did. Fingers crossed
(13) Use GL5- spec semi-synthetic lube.
(14) Run it for 5 mins with the wheels off the ground, in high gear at idle. STOP, leave it an hour.
(15) Drive gently for 10 miles. STOP, leave it an hour.
(16) Repeat 14.
(17) Pour yourself a beer and feel EXTREMELY smug
(18) Dump the lube, refill
(19) Feel free to pass this on, print it, copy it to wherever. I found people very reluctant to hand out info on Ford 9" building and a lot of what i found didn't make sense or was contradictory People are even SELLING this! This is my way of saying STUFF YOU
felt like that anyway 
) meaning i had to send it off to be chopped and altered, i now have the rear end completed- new S&W Ford 9" axle case & Strange shafts, Detroit locker diff, 4-link, coilovers, anti-roll bar and gurt big fat tyres.
nice one mate. Send us a picie then. 
