So, I've been asked many times how to do this. I've been meaning to do this thread for awhile and finally got some pictures taken last night. Here it goes.....
You start with plastic axle housings, a set of XR10 universals, some aluminum "C"'s, aluminum knuckles, a good locker, and some short beef tubes. The beef tubes should be .43"OD by 1.9" long with a .2" hole bored through it. This will reinforce the axle housing and give you something to drill and tap into to hold the "C" on. I prefer the tubes to be made of Delrin or aluminum.
Other tools you'll need are:
Dremel
Drill
3mm tap
Xacto knife
File
So let's get started.
First thing to do is remove the round boss from the outside of the housings where the stock "C"'s attach.
These should all be cut down flush with the outside of the housing.
Then you remove part of the housing where the halves come together. The object is to make the squared off ridges into small triangles so that the "C"'s will slide over them and you can clock them.
The top drawling is how the housings are stock, the bottom is how you want them to look.
The next step is to take your Dremel and smooth out the inside of the housing at the ends so the beef tube fits in nice and tight but the housing completely comes together.
You should be able to put an 5x11 bearing in the end of the housing, place the beef tube in and close the housing without seeing any gaps where the housing comes together. Just for fun, slide the "C" on now to see how the fit is, it should be tight.
So now that you have both sides done and the "C"s fit nice it's time for the lockers and axle mods. I prefer the Hot Racing spool lockers.
I've never had one fail, they are very hard metal, and the slot where the axle engages is a nice tight fit.
So this is the tricky part. You are going to be cutting the axle shafts down at the locker end right past where the axle necks up and the flat spots are. I leave 1/8" of the larger diameter when I cut mine down.
When cutting, go nice and slow, don't get them really hot, you don't want to remove the heat treating right where they engage the lockers. After cutting, you use a file and make new flats until they just slide into the lockers.
After you file the flats, you must make sure they seat all the way into the locker. Assemble the "C"s, knuckles, bearings, and universals and make sure everything fits together nice.
Once you get the "C"s clocked properly, remove the universals and drill a #39 hole and tap it out to 3mm to secure the "C" to the axle and beef tube on top and bottom.
Reassemble the axle and you're done. They should look something like this.
This mod will allow more steering, it will be stronger than most CVD's (other than Super 300's) and will widen the track width approximately 1/2" overall.