HR AX-10 dig install instructions/polishing w/pics
 

I recently purchased a Hot Racing dig for my AX-10 and noticed a couple of things right off of the bat. First, there were no instructions and secondly, the shaft that goes in and out of the casing was very rough (this shaft will be called the shift shaft from here on out). So during my build I thought that I would take some pictures and share with those who need them.

The dig was assembled when it arrived so you will need to disassemble it to get the silver plate on the tranny.
1. take the 3 screws out of the black plate of the dig and it will pull apart, set the dust ring off to the side.
2. next take the set screw out of the ring with the ball joint in it.
3. pull the shift shaft and the drive shaft out of the black plate. You can the pull these 2 apart.

Here is a pic of it disassembled minus the silver plate: (the output shaft in this pics is the one I took out of the tranny)

http://i251.photobucket.com/albums/g...g/DSC00573.jpg

4. you will need to pull the tranny apart to install the new output in the tranny. I did not take pics of this, but it is pretty straight forward. The new output will allow the screws that hold the 2 plates together slide through, they do not thread into it. You will understand this once you have pulled the 2 outputs apart and can do it without pics.
5. put the tranny back together adding the silver plate, there are new screws for the 3 holes. The 2 longest screws are for the holes that go through the silver plate, the tranny and into the motor mount. The cap screw goes in the top and the counter sunk will go below it, you will be able to tell this though just by looking. Don't forget to add the supplied spacers for mounting the plate onto the tranny. Here is a pic of the plate mounted to the tranny:

http://i251.photobucket.com/albums/g...g/DSC00572.jpg

http://i251.photobucket.com/albums/g...g/DSC00571.jpg

6.next you should and I emphasize should smooth out the shift shaft. mine was very rough and I am sure that this would cause hang up problems while trying to shift when there is a load on the tranny. The procedure I used is almost identical to the procedure used to smooth out pinewood derby axles. I started with 220 grit sand paper. I put the shaft into my dremel and held the sandpaper on it while the dremel spun the shaft around.******Be Very Careful If You Do It This Way****** it is somewhat dangerous because the shaft has the piece hanging off of it and if that piece hits you while spinning at a rapid speed it will hurt you. I accidently put my thumb a little too close and it split my thumb nail like it was glass. Once again BE VERY CAREFUL and I would not recommend doing this if you are under 16 for safety reasons. You can use a drill and it will work at a much lower speed but accomplish the same thing.

Here are a few of pics:

http://i251.photobucket.com/albums/g...g/DSC00577.jpg

http://i251.photobucket.com/albums/g...g/DSC00578.jpg

http://i251.photobucket.com/albums/g...g/DSC00581.jpg

http://i251.photobucket.com/albums/g...g/DSC00582.jpg

you can either lay the sandpaper down on something flat and apply even pressure or hold the sand paper in your fingers and wrap it around the shaft. After the 220 grit I used 400 grit, 800 grit and then 1200 grit (you can buy all of this sand paper or similar grit in the automotive section of Wal-Mart). You will only need to spin the shaft in the sandpaper for a few seconds (length of time will vary with speed of tools used). You can probably go to the next step after the 400 but I wanted to go the extra mile. After this you can do a coulpe of things if you want. You can put some automotive rubbing compund on a towel and spin the shaft in the towel polishing it a little more and/or use a dremel buffing wheel on the shaft. I held the buffer in my hands because N E 1 who has used one of the knows that it will quickly wear out in the center where it attaches to the dremel adapter rendering it useless.

pic of the buffer pad:

http://i251.photobucket.com/albums/g...g/DSC00576.jpg

7. I also use a pipe cleaner in my drill to buff the inside of the brass ferrell that the shift shaft moves in and out of. This is probably trivial but I did it N E way. here are some pics of that:

http://i251.photobucket.com/albums/g...g/DSC00579.jpg

http://i251.photobucket.com/albums/g...g/DSC00580.jpg

now you can put it back together

http://i251.photobucket.com/albums/g...g/DSC00583.jpg

http://i251.photobucket.com/albums/g...g/DSC00584.jpg

http://i251.photobucket.com/albums/g...g/DSC00585.jpg

disclamer: do this at your own risk, I accept no responsibility for N E personal harm you may incur trying to do this. It can all be done by hand, it will just take longer.

I hope that this will help someone and that it is not a redundant thread.

I am also going to modify the lock shaft to allow it to engage at a 1/4 turn instead of the full half turn. I will add pics of that when I have finished it.

8)

Thanks for that. Did you use any lube on the 'shift shaft' on reassembly?

I did not use any lubrication on any of the parts. You can if you would like to, but I would recommend using graphite to lube it instead of a grease. The graphite is dry and will not attract dirt. Dry graphite is used for car and door lock lubrication and can be found just about N E where. I also modified the lock shaft to allow it to engage quicker. I will try and post some pics of it later. Sorry that these pics are not N E clearer, I don't seem to be able to get my camera to focus on what I want it to.