[TR] Diff seals TR4A

[Randall]

> I don't really want to get
> into the complexities of rebuilding the diff,

While I don't blame you, I just want to point out that only replacing that
gear would be significantly easier than a proper rebuild.  The pinion would
not need to be disturbed at all; and since the carrier bearings would not be
changed, there would be no need to disturb the cones or shims for them.
Since the shims and bearings all remain the same, no need to check
clearances, preloads or tooth patterns.  The job is basically reduced to
popping the carrier out, driving out the retaining pin, pushing out the
cross shaft and collecting the gears and washers.  Then reverse the process
using new gears and thrust washers.  Although a spreader as the book shows
would undoubtedly be easier, it is possible to pry the carrier out and tap
it back in without the spreader.

> In which case
> could I expect the diff to last a long time yet given only the modest
> miles
> and gentle driving that my advanced years now permit?

Perhaps.  But the planet gears still have to handle the forces involved,
even when they are not turning relative to the carrier.  I think it's
unlikely you are actually seeing normal wear, more likely the surface has
spalled because it could not handle the applied load.  IMO the problem can
only get worse once the hardened layer has started to break away.  And
unless you drive only in a very straight line, sooner or later the damaged
area will come into play again.

> In Haynes page 170 para 15.6 it says "carefully withdraw the inner axle
> shaft assembly ect". I have found the bearing retainer very reluctant to
> come out together with the inner axle assembly after removing the 4 nuts.
> Does this just need more pulling out force?

There's an old joke in there somewhere, about British instructions.  On the
Stag, they came out with only some modest persuasion with a brass hammer
applied to the flange.

-- Randall