After that is removed you're left with this.
Working with it attached to the lower part of the case is pretty difficult, so just flip it over and take these 2 screws out.
Then I needed to remove the needle. I tried prying it off but that was damaging the face, so I removed the 2 screws for the face plate tilted it so I could get a small flat head screw driver under it, and used the screw driver like a small drift to push the needle off the shaft.
Here are all of the main parts. The "J" looking metal line is the stop (0 rpm) and it is attached to a shield that covers a tin disc.The disc is attached to a shaft. The shaft has a spring on it that keeps the tach at 0 while not running and provides resistance. Below the tin disc is a magnet, the magnet is what's connected to your tach cable. The faster the magnet spins, the stronger the magnetic flied between the magnet and tin disc gets, which makes the tach move. The resistance from the springs means the magnet must spin fast to move the shaft futher clockwise.
I then moved the shield. To do this I just removed the 2 screws closest to tach cable mount.
When I got it off I jlooked to over and found some slight signs of rubbing on it.
I then moved the needle again and it was returning slightly faster, but still pretty slow.
I then sprayed some wd40 down the shaft hole through hole on the top plate and on the bottom of the top plate. After that I pack some white luberplate grease in both sides.
The needle moves freely now and returns very quickly. Luckily I had another dics cover from the other tach I took apart, that happend to be in better shape. I installed it and it still moved freely and returned quickly. If you don't have a spare you could bend the tabs up slighty to pull the cover away from the disc, or sand the inside of the cove down a touch.
Now this is by far the hardest part. Getting epoxy in that ring, mounting the ring, and securing it with a large hose clamp. Again just take your time, and be ready for a fight. That ring just doesn't wanna stay in plce for some reason.
Let it set up over night and that is that. take the clamp off and mount the tach back up. I haven't tried mine yet but i have high hopes. I plan on mounting it up and tring it out tomorrow.
