In a message dated 7/12/99 11:23:09 AM Pacific Daylight Time,
rbownes@neworks.net writes:
<<
On a related note, disassembled two TR6 diffs over the weekend. Both have
the same failure mode, both appear to have had cracks in the pinion gear
that come from a stress riser from the original machining. One in fact had
a tooth break in half with the crack underneath still in place (and still
oil stained). Both have had a tooth shear off at the base of the tooth with
obvious beach marks rolling across the root.
Other than too much HP, any suggestions as to why?
>>
Bob & FOTers,
Ring and pinion failures in Triumphs are usually caused by bearings and
selective washers wearing out and the shock loads caused by the loss
of preload and/or proper running clearances. Old age and lack of maintenance
are more likely than causes than improper design.
For rear axles rebuilt out in the field, sub (Standard -Triumph) work is most
often the cause. I used the guess and paint the teeth + wire wheel hammer
method until I had access to the proper tools. There is a large difference
between the two routes! I spent a long time learning from the factory
service school
teachers, and obtaining all the factory tools. I have built quite a number
of Triumph
rear axles, and have yet to have a failure.
Part house bearings may very often be the same, but not always. Factories
could and did require special bearings some of the time. I remember the first
time that a bearing house sold a timken bearing to me, and brushed off my
notice that their bearing was missing the "SR".
I also well remember the first TR rear axle that I set up after Jaguar
Rover Triumph started supplying the "just as
good as" domestic pinion head inner bearing.
Price may reflect a better control of specifications, or a higher mark up; or
some times both.
I did not build my race team with things that "are just as good as", but there
are no doubt some good Ugo parts out there; and the Triumph Factory is slow
in responding to requests for spares. Napa can be a good resource, just use
caution.
Good Racing HP
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