After throwing a BLX 85 & 3800kv 3556 motor in my granite, it has snapped 2 rear diff plastic input gears on 3S & one on 2S. The truck is easy to work on but I'm getting tired of replacing this part. I already tried filling the hollow part with a 2-part plastic epoxy & that seemed to work for a bit but it just couldn't handle 3S. Then I snapped another on 2S So after brainstorming a few ways to fix this mess, I decided to take the easy route. I used the broken gear end of the input (the part was already filled with epoxy), a wheel axle (AR310784), & a 2x10mm harden steel pin. I drilled a 5mm deep hole in the center of the back of the gear with a 1/4" bit Then I drilled into the center of that hole with a 3/16" bit 10mm deep (The bit was 15mm deep into the gear) This allowed the axle to be inserted clean into the gear enough to cover the pin hole with a VERY small amount of wiggle room. Last I drilled the hole for the pin with a 3/32" bit. This is the hardest part but the hole in the axle lines up dead center in the groove. If the axle is fully inserted in the gear then the hole will have to be drilled 1.5mm from the end of the gear & use the groove on the axle to line up the hole. I used a caliper & did the mod in less than 10 minutes. The wiggle room comes in handy when inserting the gear back in the slipper clutch plate. The 2nd bearing covers the pin perfect & the slipper clutch plate sits right where the black part of the finished gear ends. I thrashed the truck on 3S today with 4 whole packs & the gear is holding up magnificently. Even if the gear decided to fail, just like the original part, there's no where for the pieces to go. I made another one for the front but it doesn't seem to need it. These pictures were taken after the runs. There's no distinguishable wear on the drilled holes on the sides.