Im leaking motor oil from a black color rectangular cap that goes on the bottom of the transmission. Im guessing my rear main seal is the culprit. Is this something i can fix at home? Whats involved? Is there a DIY with pictures that someone has documented? Thanks in advance!

 

Hi, nothing to it if you have the equipment for it.
1. Remove driveshaft
2. Remove transmission.
3. Remove flywheel
4. Remove bad crankshaft seal
Installation is just reversed procedure of the removall.
It took me one day about 12 streight hours under the truck to replace my transmission so this job should take about same amount of time. Did you get any shop estimates?
Good luck to you.

 

you will need these parts to do the repair correctly: rear main seal, rear main seal plate, sealant, trans cooler line seal rings(X4), 1 qt of trans fluid for topping off, trans electrical connector/pilot bushing(might as well because its probably leaking), and trans lock tab if your picky.

as said above the steps: place vehicle in neutral, remove front flex disc and support driveshaft, remove shift linkage, remove trans cooler lines from trans, remove bolts from torque converter, disconnect trans connecter, remove all trans bolts, remove trans, remove ring gear, remove rear main seal/plate. clean mating surfaces completely and ensure no oil remains on surfaces, place sealant along mating surface of plate, install plate, press in rear main seal, install ring gear, replace trans connecter/pilot bushing, install the rest in reverse order.