How to reinstall the shaft seal for the shift lever (8657163) properly

[dochidalgo]

The seal was replaced twice by GM local dealer mechanic, so unsucceded as it was installed for me . The issue is, the trans fluid keeps leaking. Then, I suppose there is a proper way to install it with success.
The mechanic had installed from outside of the tranny case, the seal has a rubber center sourrounding by a metal ring. The rubber (seal) ring runs along the shaft and the complete seal seats in the tranny case...I've been used Mobil 1 ATF (syn)....hmmm..smaller molecules = leak??. Anyway, I change the tranny oil with Mobil 1 again, thinking the problem was corrected with the new seal ......bad movement!
I was wondering in attach there a O ring too....I really don't know how to mend this leak.
Thanks a lot for your help
Regards
Doc

[dochidalgo]

Anybody???
Doc

[Rob B (shoebox)]

Perhaps the inner part of the seal needs to be stretched out a little before putting it over the shaft. I have not really looked at one of those seals, but it might be getting folded over or something during installation (like what sometimes happens to the water pump driveshaft seal). I would think a little extra care and attention during install should make it a success.
I guess another possibility might be if the shaft had a gouge in it. There just isn't that much to it. The book says remove the old seal with a screwdriver and tap the new seal in with a 14mm socket.