The plastic gears are under the 1/10 Mad Crawler MOA crawler parts. A lot of the parts here are the same as the Mad Torque. The small 2nd and small 3rd gears shown there will work for you too. Get them at the same time.
1/10 Exceed RC Mad Crawler Part & Upgrades
I measured the tang in the MT locker, it's somewhere in this build. I believe it's 5mm wide.
Once you cut Axial shafts down to length, they're only 4mm. Therefore, cutting a 5mm tang on them is impossible.
The RCBros locker is only 2mm wide. That's why I bought their locker and the stock Berg 4th gear to match it's bolt pattern.
The MT locker bolt pattern is different. When my plastic gears show up, I'll be tossing out the 4th gear and only running the 3rd and 2nd.
Still a significant weight savings because the Berg 4th gear is lighter than the MT 4th. Coupled with the plastic gears, should be a significant weight savings.
Can't remember the Berg 4th part number, but it's in a photo next to the RCBros locker. Page through the build and you should be able to find it.
I haven't confirmed the measurement of the OFNA universals. I am certain they are larger than the Axial shafts. I just remember them being bigger and more bada$$ when I put a set in my sportsman.
I doubt they are more than 5mm, and therefore still would not work with the MT locker. It's essentially useless, and not worth buying.
A couple posts back, I put new bearings in the cases. I had to order the bearings for the ends of the tubes (right next to the case). The stock bearings are too big to hold a 4mm Axial shaft steady.
They were only a couple bucks. 4x8x3mm or 4x10x3mm. I can't remember exactly. The width is 3mm for the stock bearing. Whatever the O.D. of the tube's bearing seat measures, you need to get an I.D. of 4mm to hold the Axial shaft once it's been cut.
I don't have the invoice here, and don't want to tear the rig apart to check it for you; but it's one or the other listed above. You'll have time during the build process to get the right bearings ordered.
Also, now that I've been through the process, there's no need to custom order 3mm wide bearings at all. There's room between the case and the tube bearing to run a 4mm wide bearing, which is likely the same bearing that the VP knuckle uses, on the outside. Traxxas or Axial bearings I already had on hand.
I never checked it. Just took the measurements of the stock bearings, and ordered new 3mm wide ones. Hindsight....