Many people falsely believe the engine must be removed from the vehicle to replace the seal retainer. The reasoning for this is because a couple people for years now (who are looked up upon as experts..?) have convinced others the retainer cannot be removed from the engine block without removing the oil pan first. This reasoning is absolutely ridiculous and a disservice to all Isuzu enthusiast who have listened. In photo #5 its clearly visible there is more than enough clearance between the bottom of the crank seal retainer and the top of the oil pan.
The factory service manual has a TSB for warranty replacement of this part which allots a B level mechanic 1.3 hours total to complete this job. Being that it requires 4.5 hours to remove the engine it's safe to say the dealership mechanic didn't go about replacing the seal retainer by removing the engine too. My fastest time which includes cleanup is 1.4 hours.
The correct instructions on how to replace the seal retainer are:
First remove the timing belt & crank sprocket in the same manner as if you were replacing a timing belt.
Then;
-Pop the crank seal out of the retainer.
-Remove all nuts and bolts holding the retainer in place.
-Remove the 2 lower studs that protrude thru the oil pan.
-Pry the seal retainer away from the engine block with a screwdriver. You may have to work around the retainer little by little to free it.
-Once free, lift the seal retainer up at a 45° ish angle as you are guiding over the end of the crankshaft.
To reinstall.
- Place the retainer gasket against the engine block. A dab of RTV will hold it in place for you.
- Apply RTV on the "hoop" side in the corners of the oil pan gasket.
- Slide the seal retainer over the crankshaft towards the block.
- Align the seal retainer so the crankshaft is centered in the opening and the bolt holes in the engine block are just below the bolt holes
of the retainer.
- Use a screwdriver inserted into the lower bolt holes to apply down force onto the seal retainer. This will compress the oil pan gasket &
compression is what make this seal work.
- While prying down push the seal retainer towards the engine block & over the alignment dowel. The retainer will "SNAP" in place when
alignment is made.
- Install seal retainer bolts & check the oil pan gasket. Verify you haven't pushed it out.
- Install 2 lower studs and nuts for the oil pan.
- Install the crankshaft seal.
- From this point its simply reinstalling the timing belt.
Caution;
DO NOT INSTALL THE CRANKSHAFT TIMING BELT SPROKET BACKWARDS. If installed backwards when you tightening the crankshaft bolt it will shove the harmonic balancer into the timing belt sprocket. The sprocket then will be pushed into the seal retainer crushing it.