TRX4M diff cover for through axle - 6x6, 8x8

Here's a diff cover that can be installed on to most TRX4M axles to convert them in to a through axle for a 6x6 or 8x8 design. I've included a steering linkage for the Injora +4mm axles, to allow you to create a 6x6 or 8x8 with multi-axle or AWS

This design will only work on the standard style axles, like the stock design that uses a diff cover, I have tested with the stock plastic axles and Injora +4mm axles (linked below)

If you are creating a typical 6x6, then I recommend using a diamond axle on the rear, as this allows you to switch the diff ring gear to the opposite side for correct wheel rotation. Similarly, for an 8x8 you would do the same on the front axle also

To assemble simply push the two small bearing holders in to the cover, you may need some light force or even to trim these parts ever so slightly with a knife (I have left the tolerances purposely very tight). I recommend using four M2x25mm bolts with nylon nuts to secure the diff cover in place. You will likely need to drill the axle housing holes out to 2mm to suit (I haven't had any issues doing this, but proceed with caution at your own risk). Alternatively you could use M1.6x25mm bolts, but nylon nuts appear to be unavailable for this size, and standard nuts will likely work loose over time

You'll need: 

• a pinion that matches the existing diff gears
• two 4x8x3 (MR84RS) bearings to hold the additional pinion in place
• four M2x25mm bolts
• four M2 nylon locking nuts

For the steering axle you'll need: 

• three M2.5x10mm bolts 
• one M2.5x8mm bolt
• 10mm length of M2.5 threaded rod to assemble the arm that attaches to the servo (I screw in an M2.5x12mm bolt on one side and cut the head of with some decent pliers)

Compatible with these axles: https://www.injora.com/products/injora-4mm-aluminum-axles-with-lay-down-servo-mount-links-for-1-18-trx4m?variant=47384264769823