It is on the front of the crank shaft. It seals the oil at the crank pulley.
There is one on each end of the crankshaft. The front main seal is at the pulley and, while the rear main is at the transmission end.
The front main is behind the crank pulley. The rear main is behind the flexplate/flywheel. The trans has to be removed to access this one.
5-6 hours
Front main seal or timing cover leak.
on the top of the truck
Failed front main crankshaft oil seal.
Should pull the drive pulley and then you can pop off the old seal with a screw drive and press in the new seal.
Yes
I am not sure of how to instal a rear main seal on '89 dodge D100 with a v6.
Oil leaks because a seal has failed.
Obviously a seal has failed.
For the main seal you need to split the engine and transmission, whether it's pull the engine or drop the transmision, it's up to you. Then remove the torque converter and pop out the old seal and put in a new one. For the axle seals, you need to pull the axles.