It is too late, you removed the top rear bearing quicker than I could write. To secure the bearing is to prevent it from shooting backward when undo the speedo nut. That is done by fitting a short 7 mm bolt and a thick washer pressing against the bearing.

Reason for unscrewing both nuts without opening the peening is, the nuts are mild steel and both shaft are hardened. When unscrewing the nuts, the peening will open as the nut turn with no damage to the threads. Trying to open the peenings using any tool might damage the threads.

As Ken mentioned, the shims placed between the out put hubs and the crown bearing are determining the preload on the bearings and the backlash. worn bearing will loose the preload and more shims need adding. By adding more shims you also push the crown wheel toward the pinion. This is mighty important to have no more play between the crown and the pinion to 0.15 mm. Further more, when you removed the lower shaft and the rear double bearing, you found a shim between the bearing and the ''4th gear'' wheel. That shims is also very important. Due to wear, the pinion drop causing the gear box to haul. The pinion need the correct height (against the crown whee. Look at the numbers engraved on the pinion crown. More later when time comes

Anyways, onwards!

Coming back to the box today with fresh eyes (and jasu's help) eventually saw the main shaft liberated, along with a whole other bunch of bits on top of it. If anyone wants to chip in with the correct names, feel free



I'm not sure the correct way to do it, i ended up removing the output shaft which dropped everything a bit lower at the bottom of the box, this seemed to help. After removing the input shaft bearing cover (on the left in the first photo), the next step is another Haynes classic - remove the circlip. Easy to say, a total pain in the ass to do with numb fingers. 20 minutes later it was off.







Once this is done, use a soft mallet or a bit of wood and a hammer to drive the input shaft backwards into the gearbox and remove once it is free!

I guess i could have stopped dismantling here, as the input shaft is now free to replace the bearing on, however I am also doing this to learn about gearboxes so i carried on and lifted out the lump of pinions at the bottom of the box. I don't have a manual in front of me so the name escapes me. there was one shim at the back, and one shim and a bearing at the front which I removed and kept with the shaft.





The box is now looking almost empty and much less scary! Just visible in this picture is the front inner race of the lower rear bearing (what a mouthfull!) I nlifted this out and put it with its companion from the outside of the box in a baggie to stop it vanishing. The outer casing of the bearing is still in the box, but i see no reason to remove it.



Haynes now tells you to remove the little lonely pinion at the bottom of the box by removing the pin and blah blah blah. I tried for 10 minutes and couldn't get the pin out, so i gave up an soaked it in wd40 to clean out any gunk or metal shards nearby. I would like to have done it properly but couldn't shift that bastarding pin to save my life.



I did notice some interesting marks on the teeth...are these supposed to be there?



So this is pretty much where I am. I've left the bits soaking in petrol to clean them up and will order the top front and rear bearings along with gaskets tomorrow.


To be continued!

you might as well fit a set of synchro springs while its all apart.

Martin,
considering that the specified torque for those nuts is 50 to 65 lbs.ft. / 7.0 to 9.0 kgf.m. , you may begin to understand why many gearboxes have experienced problems.
I use Loctite to secure them when reassembling a box, rather than rely solely on that cr@p 'staking the nut' business.

A good pair of calipers, either digital or old school, should help you to determine what the thickness of the shim would have been.

p.s. Have you got a compressor? A very handy item for making sure that everything is clean before reassembly.
Also, I never bother to remove that idler gear for reverse, unless there's visible damage on the teeth.

Thanks again for the comments everyone. Viking, that all sounds very complicated - i look forward to it with only slight dread.

Sean, I'll trust you on that and order a set along with the gaskets tomorrow.

Ken, I'll make a point of buying some loctite for the reassembly of the box. I don't have a compressor, however I've always been looking for an excuse to buy one.......!

So my shopping list for tomorrow is:

Input shaft bearing
Top rear bearing
Synchro springs (I'm guessing the SPOG ones that ecas sell?)
Output hub paper gaskets.
Replacement shim of the same thickness as the broken one (Got an e-mail from Rick Pembro saying he can send me one once I determine the size of the old one. Vernier caliper on order.)

Anything I'm missing?

Or, when you have scrapped parts enough, you can make a tool from broken rear cover...


Drill big enough holes, so big that socket will fit, and with that there isn't any problems when loosen/tighten the nuts. Put 1st and 4th gear on, it can be done when top cover is off, that is locking the gearbox...


I also cut one top cover, very easy with that to look everything works right way...

Nice one Martin - looks like you are doing a great job! I'll hopefully be rebuilding my spare box to fit a Quaife LSD during the summer sometime. I'll need this thread to do it!... great photos btw. I hope it all works out for you

Not much to report today, spent most of it exploring Glasgow's museums which was nice.

I ordered the bits I need from ecas which should be here tomorrow, but the bearings will take longer as I forgot to call them this morning, so I assume it will be Monday before I can get a hold of them

I had bought a cheap ultrasonic cleaner from Lidl a few weeks back to clean up a moped carb, so i thought I would give it a whirl with some of the gearbox parts. I know this is overkill but what the hell, eh? Couldn't believe the colour of the water after! I decided against putting the bearings in to be safe...think they would survive it okay?





I also took the mainshaft apart into its various bits. This is yet another time that haynes tells you to simply separate it into its parts, without telling you that it is like a freaking combination lock which can only come apart when all the independently spinning bits line up just so...







The rest of the parts are still soaking in a bucket of petrol in the garage. I'll give them a wipe off and get them apart tomorrow too.

Until next time! (and thanks for the kind and helpful comments everyone )