A lot of progress has been made on the diff over the last three months and it’s now effectively ready to be re-installed.
The diff was stripped down, cleaned and prepared for painting. I decided not to strip the whole crown wheel and pinion assembly, thinking that if it ain’t broke etc. and I didn’t want to unsettle anything. However, I did split the two diff halves as a new pivot mounting needed to be fitted.
I sprayed the individual parts in primer and then in a 2K black paint, which was matched to a black powder coated finish. The trailing arms, anti-roll bar and other parts were powder coated and I didn’t want there to be a difference in colour once assembled, hence the paint needing to match and the paint supplier did a really good job.
The one half of the diff was placed in a vice, but in hindsight, it really needs some sort of a rotisserie type setup to be able to spray this part of the diff in one go – only once the final black coat had dried properly did I notice some areas where I didn’t get the paint done properly. Anyway, I’ve touch this up with a brush so that you wouldn’t notice it, but it’s not first prize. Lessons learnt! Oh yes, I now also have a yellow vice....
My paint supplier matched the red colour for the bellow chambers and these were painted. Once thoroughly dry, the units were re-assembled with new bellows and seals for the connections and re-installed – I’m very happy with how they turned out.
All the nuts, bolts and washers were zinc plated, so assembly of the diff could begin.
The two halves were reassembled with a new rubber boot and pivot mounting, along with new O-ring seals at the pivot joins – the cradle I had made to support the diff made the job infinitely easier than my past experiences.
The anti-dive brake mechanism was then tackled with new felts seals. New nylon bushes were used with the old shims, which were cleaned up. Once the tolerances were measured, the caps were replaced with new O-ring seals.
I had the brake callipers overhauled at a brake specialist, but asked them not to paint them – I was thinking of painting them myself. My paint supplier suggested that I get them gun-coated, a baking process that is brake fluid resistant and offer better scratch and chip resistance than powder coating. I had to strip the callipers again to get this done, and once I got them back they were reassembled. The colour choices were a bit limited – I would have liked them done in grey to match the front callipers, but the final result is still great.
The drive shafts were cleaned and new seals were fitted to the drive shaft housings. New outer seals were fitted to the backing plates, which had been powder coated, and these were re-assembled onto the drive shafts with new bearings, washers and lock nuts. I had a special tool made to fasten the slotted nuts to the required 200Nm.
The drive shafts were inserted without too much fuss and new hand brake shoes fitted.
The handbrake cables were really grubby and I wanted new ones, but they’re no longer available. Nevertheless they cleaned up nicely and the metal parts were plated – they really look good, except for the rubber boots closest to the brake shoes. I found a part number on the boots and they’re still available, so I’ll order these – even though they cost the same as the fiscal budget of a small African republic.
New discs were fitted along with the callipers, steel brake pipes and new rubber hoses.
The trailing arms were powder coated and the rubber bushes have been replaced with nylon bushes for rigidity – the original threaded insert has been retained. I will fit these once the diff is in the car, as the diff cradle obstructs where the nuts must be inserted and secured.
The diff is effectively now ready to be refitted, except that I’m still waiting or the diff flange seal to come. Once this is here, I can fit the seal and torque the flange, and then set up the diff mounting according to the specs.
Here is a detailed before and after pic of the work done so far:
BEFORE
AFTER
I'm sure the purists will cringe at what's been done here, as the diff originally came out of the factory sprayed overall black. Some might think this over-restored, but stuff it - it's been tremendous fun and very satisfying - for me it looks good.
