Diff Oil Leak

[Mike Wattam <101714.1343@domain.elided>]

Hi Nick

You wrote;

"The existing pinion seal looks OK, with a good fit 
when checked against the quill shaft. However looking at the 
diff itself  where the seal fits into the diff the seating is not 
continuous. There is a 1 inch piece missing from
the bottom right hand quadrant of the seating in the diff nose.
When tipped up oil pours through this hole."

Oh dear, you seem to have a problem!

The piece missing you refer to, is not correct, there must be 
continuous metal around the oil seal to enable the outside of 
the seal, to seal.  Clearly all that is stopping all the oil coming 
out continuously, is the quill shaft bearing oil seals.  It must
be the 'person' before you has broken the housing when 
trying to remove the oil seal.  SOB.

Rectification looks very difficult.  You could try a filler, but I very 
much doubt that this would work.  Welding is impossible without 
stripping the diff (welding heat, spatter and dirt getting in front 
bearing being the problem).

Stripping and rebuilding the diff again is impossible without the 
correct special tools - you need a spreader to refit the diff 
crownwheel assembly.  

Fitting your gears into another casing is very problematical, as 
well as the 'spreader' problem you will also need other height 
guages and a dummy pinion to set it up correctly, then setting the 
actual mesh of the gears to avoid noise is another problem - a 
problem which requires very specialised skills indeed.  So this 
is not a good bet at all.

Second-hand diffs tend to be noisy (the normal reason why they 
are removed) so finding a good one may take time and a lot of 
heavy disassembly/assembly.

So, the practical (but expensive) answer looks to be a service 
exchange diff assembly.  The good point is that Rimmer Bros 
now supply these with new gears, so a quiet and long-lasting diff 
should (SHOULD) be assured.

Sorry about this depressing news.

Mike Wattam
Triumph Stag Register