What's the problem with the mechanism you're going in to fix?  Is it not spinning or spinning-pulsating at the same time?  Leaking oil from the top, bottom or both?

The Unimatic shop re-operation manual from the library is great, familiarize yourself with the steps before beginning and then when reassembling, take your time and follow the written instructions and parts breakdown diagrams carefully.  

Is anything wrong with the transmission?  Bearing noise during spin, torque spring in tact and it spins up, pulsates fine, fan isn't too noisy? Leaky oil pump?  If all of the above are ok I'd suggest changing out the oil and calling it good.  The whole "If it ain't broke don't fix it" applies well to these transmissions.

Ben

Looks like Greg beat me by a minute! 

Brake?   Is there a brake on a unimatic???

Yep!  There sure is.  Without it, the tub would coast for hours and hours ;)

Oh yeah, duh....LOL    

You're awesome Ben, THANKS!

Gaskets - head to the auto parts store.  For the case I've used cork in the past.  For the pump, I get the Fel Pro black gasket material.