While I was installing the new transmission, I figured it would be a good idea to update the rear oil seal. I bought the seal conversion kit from Moss Motors - Part No. 833-415. The instructions that come with the kit are very thorough and easy to understand, so I won't repeat any of it here... so consider all this info just supplemental.
Here's what you're starting with... flywheel and rear engine plate removed...
Installed the supplied drill guides and oriented the crank per the instructions...
At this point, after reading the instructions, it was obvious to me that I REALLY needed to make sure I didn't drill through the engine block or through the rear main cavity. Doing so would mean chips getting inside the rear main caps or inside the engine itself... which would mean a WHOLE lot more work for me, given that I'm doing this on an engine that's currently in the car (and that I sure don't want to take out anytime soon).
So my best hope for insuring none of this happened was to make sure I was drill and tapping to the exact required depth... and not even the slightest bit more.
I took my 4.2mm drill bit (that I bought from someone on
Amazon.com), and slid it through the bushing until it hit the block. Then I marked the portion sticking out with tape. From this, I measured up exactly 10mm... the required depth per the instructions. I didn't go even the slightest bit more, and erred on the shallow side. I lined up the mark I scribed on the drill bit with the end of my drill chuck, so the chuck would run into the drill guide when it hit the required depth (insuring I couldn't do any further). Then I proceeded to carefully drill the holes. Afterwards, I blew the holes out with compressed air, and then stuck a thin poker into the holes to see if I could poke through the bottom into something. Fortunately, all the holes looked good... none of them appeared to break through anything.
Since I erred on the shallow side with my holes, I needed to make sure I didn't run out of threads when installing the screws. So I took the 5mm X 0.8 tap I bought (also through
Amazon.com) and I ground the end down a bit... to give me a few more full threads closer to the bottom of the hole.
The conversion kit comes with nice drill guides... but no means of guiding the tap itself. I don't know about you, but I have a hard time making sure I'm starting a tap perfectly straight... especially when I'm hunched over, doing it by hand, with my body shoved under the dashboard and my legs through the hole in the floor where the transmission is supposed to go.
So what I did was... I took the supplied drill guides (which I no longer needed) and carefully drilled one of them out to 5mm, making sure to keep my new hole perfectly concentric (a drill press would be best for this). So the drill guide became a tap guide. Then it was really easy to get the tap started and the holes tapped.
Following the rest of the installation instructions, this is what you end up with....
The last part was definitely the hardest part. The photo below shows how much material has to be removed from the engine plate in order to fit around the new rear seal. I really don't have an easy way to do something like this, so needless to say it was a pain in the butt. I ended up drilling a million small holes to remove material, and then used a small grinder to cut out the remaining and clean up the shape.
And here's what it looked like after material removal.
And lastly, here's the finished product... seal conversion done, plate back on...
If anyone has any questions about any of this, feel free to send me an email!