[Mgs] MGA Transmission Leak

[weberstevej at aol.com]

1959 MGA 1500 with splined yoke and internal tailshaft seal.

I have replaced the tailshaft seal twice and still have oil leaking out at the
seal/driveshaft yoke at the rate of a half pint per hundred
miles. I am using 20W50 oil. This was a frame off restoration. The firstt seal
leaked before I had even driven the car under power. I had not replaced the
tailshaft bushing initially.  I pulled the transmission and replaced the rear
bronze bushing and installed a new seal. At this point the car was driveable
and leaked at the current
rate (.5p/100mi). There was a little wear on the yoke of .0015" on the
diameter near where the seal made contact. To remove that variable I built a
shim of .250", inserted it between the rear end and the
driveshaft to move the yoke into the tailshaft .250" to place the oil seal
onto a virgin portion of the yoke. Same leak rate resulted. When I replaced
the bushing, I did machine in an oil slot in a "X" configuration centrally to
the oil hole similar to the original
bushing. The grooves extended the full length of the bushing to the front, but
stopped short of the rear by at least .250" . I don't know if this oil journal
is allowing too much oil pressure to be exerted on
the seal causing it to leak, but based on the design of the oil "pump" I
really doubt that there can be that much pressure generated. So, with all that
I'm ready to replace the rear bushing again, without an oil channel and
install a new seal.

My questions are;

1. Does anyone have any other ideas or suggestions?
2. Can the tailshaft housing/gearbox extension be removed with out pulling the
engine and transmission?

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