leaking transmission fluid 1974 fleetwood

[ithaca1230]

This is what mechanic sent me. Any ideas how to deal with this. Thanks

Hi Bill,

This is the transmission output driveshaft leaking inside the yoke where it slides into the transmission. There appears to be a "plug" that the fluid is leaking out of.

[Dave Shepherd]

This is the seal to correct that. https://www.ebay.com/i/310556649408?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=310556649408&targetid=474173631829&device=c&adtype=pla&googleloc=9004949&poi=&campaignid=1669934834&adgroupid=65058350339&rlsatarget=pla-474173631829&abcId=1139296&merchantid=6567084&gclid=CjwKCAjwvJvpBRAtEiwAjLuRPfm3WZqVrGSc1mOKA5jIaUtYz1l3Y_lgaGpTLIHM8sfhT_iZRlDUYRoCD2wQAvD_BwE

[ithaca1230]

is this a relatively easy fix? thanks

[MikeLawson]

Here is another seal kit which includes the O-ring, output shaft seal and transmission tail shaft housing gasket.  I bought this kit to fix my transmission leak but I have not yet installed it. The tail shaft housing must be removed in order to make the repair but I don't think it will be too bad a job.

Seal Kit: https://www.ebay.com/itm/Rear-Tail-Extension-Housing-Reseal-Kit-Fits-GM-TH400-THM400-3L80-Transmissions/111495961324?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

[bcroe]

A couple output shaft seal arrangements were used.  One used an outer yoke sleeve
that extended over the output shaft past the splines.  It slid on that big O ring on the
shaft, as an oil seal.  To let air out there was a small hole in the center of the yoke. 
The hole leaks oil if the O ring fails, or if an output shaft with no O ring is used. 

That O ring is in every TH400 rebuild kit.  If it fails, it is a hint at what condition rest
of trans rubber is in, some in far more critical functions.  The trans should be apart
every couple decades for a rubber refresh, independent of miles, mine are. 
Bruce Roe