I've got a 90 2wd silverado 2wd w/ auto transmission. Truck sat for a couple of weeks and I noticed one day fluid leaking from yoke area. Cant tell if it is from whatever sensor it is right at the end of the tranny or from where the yoke goes in. Any help? Rear seal or something else?

 

about 90% of the time it is a gasket or a seal... but really dont know in your case.

 

lol...funny, i just noticed today that my gasket started leaking from the pan...check it out...

 

Probably rear yoke seal, easiest place to get dirt in. But clean area well and run truck, then check. If it is around sensor (ulikely) it will be pretty obvious.