I just couldn't help myself - it had to come apart. I'm now certain that corrosion 'swell' caused the break out on the diff bearing housing - the crownwheel backlash/carrier bearing preload shims were well rotted (on both sides) and totally unusable. Corrosion damage had spread to the main diff casing on the 'bad' side also (and the o/s bearing housing was of course scrap as has been shown before.
The crown wheel/pinion (3.64:1) is a little worn but is re-useable. I shall probably use the case as a check jig for my gasket production.
As for the box itself the bearings and synchro rings were worn but the gears seem all ok with the exception of the reverse idler which has the usual 'grating into reverse' tooth form (ie.buggered). The mag.drain plug was a work of art - filings tree of huge proportions so something was wearing !!
The diff cover plate was a real horror - badly rusted and actually holed on the top flange return.
The covers are no longer available and I suggest that everybody cleans and repaints theirs when they get the chance (can be done on the car) or even just give a spray with anti-rust. The pics give an idea of what Varts looked like after I'd cleaned it up a bit.
Rust had spread to the plates inner face and was distorting the sealing area.
Mac.
