Differential complete - the pig is tamed

The assembly instructions said that this kit was "a bit of a pig", the pig is now tamed! and I have a fully functional differential.  Pictures do not show much difference, but the work to get it operational has been substantial.

I have used car engine oil for lubrication during trial assembly, to enable assembly and removal of close fitting parts.  I have re-learned how misaligned, close fitting parts can jam if they are forced!  Penetrating oil has had to be used occasionally.

When first received, the two halves of the differential were close fitting and difficult to separate; I have filed some small indentations into one half so that a screwdriver can be inserted to help with separation when that becomes necessary .  There will be plenty of flat surface if I decide to use some sealant to keep grease in, and away from the working surface of the drum brake (the outer circumference of the diff).

I had an “OOPS” moment when I had assembled everything and found eight spacers/washers left over.  The pinions in the differential could move sideways but for the grub screws.  These were re-assembled taking more care to follow the drawings provided and insert the spacers.  Some dexterity was needed to align the through bolt with the spacers.  I found that the bolts are easier to assemble to the spacers if they are passed through the arbor from the pinion end.

While preparing the spur gears for assembly, I noted that only one pair of keys has been supplied, and assume that the spare slot on the shaft is not needed.  I suspect that the same will be true of the wheels themselves.

At the outer end of the half shaft is a length of shaft machined to fit the inside of the wheel.  The inner part of the roller bearing needs to be passed along this part of the shaft, but seems to be an interference fit on it, which presents a challenge to someone without the strength/ equipment/ skill to force it into place.  I am considering the use of some abrasive to ease this fitting.

On a lighter note, the Lykamobile has obtained a nickname of ‘The Wench’, as she is claiming time alone with me in the garage.  As described previously she is suspended from a “Wench Winch”, and my set of spanners has been converted into a set of “Wench Wrenches”.  The least said about ropes and shafts the better, in this context; Shakespeare was much better at that sort of language.  (She is now tied up and shafted).

For my future reference, this is what I have done
Put RH hand shaft in position, this one has tighter fitting parts which are readily assembled on the bench, but can jam on assembly in situ.  With lubrication and care, the inner end parts are pushed into place, in order:
1. Roller bearing inner part
2. Arbor which can be used to prevent the bearing from becoming mis-aligned
3. Differential bearing, over the arbor.
4. Spur gear key
5. Spur gear
6. Spring washer
7. Half nut (hand tighten only!)
In the absence of a wheel on the outer end, a length of 28mm plumbing pipe (about 13.5 cm long), a wide 30mm (Form C) washer and an M16 nut can be used to prevent the shaft going too far in.  On first assembly, tightening the outer nut had  the effect of forcing the inner roller bearing into place against a slight interference fit (I have no idea if it is now removable!)   Thanks to sheddingitall.blogspot.co.uk  for his illustration of a similar arrangement which I have imitated.
The second (left hand) shaft is “a pig” to assemble (quote from assembly instructions)
A diagram for my future reference:

With the spring washer uncompressed there is too little clearance to put the half nut in place. The spring washer is 3.5 mm deep, but 7 mm when not compressed. There is less than 5mm available!

I got an anti-vibration, serrated washer to use if I couldn’t fit the spring washer supplied.  It was not needed.

Then it got greasy!
Re-assembled everything with a liberal coating of grease.  The differential jammed solid when the two halves of the casing were bolted firmly together.  After much thought and experiment, I tracked down the problem to the mounting within the casing being slightly smaller diameter than the plain bearing between the differential casing and the half shaft.  The plain bearing was not only held to the casing but was also clamped to the half shaft.  A Vernier gauge confirmed my theory.  So something like 0.2 mm had to be removed from the bearing mounts on the casing.  Everything now rotates smoothly.

I am considering the addition of spring washers under the nuts which hold the two halves of the differential casing together.  On one side, the chain sprocket is bolted on and should hold it together, but on the RHS, I don't fancy the idea of the bolts vibrating loose.
The screw threads for the through holes into the casing are not long enough, so the bolts will have to be shortened.

The next kit has arrived - the brakes.  As we don't yet have wheels, we will be able to stop before we can go!  There is also painting to catch up on; quite a few knocks and bumps, etc.