Wltoys 12428b (part 11: fixing rear diff failure)

So we have two of these cars.  Up until now I'd been writing about the first car, which is now in the process of being painted white.  The second car came out of the box the other day, and taking both batteries we went and ran it just now.  Such fun!! Reuben had a great time, which after all, what this all about; having fun.

..but on the way home, both batteries near dead, having bounced it all over the place and tumbled here and there and generally had an awesome time, we're literally rolling downhill on the way home and i was thinking it was making a bit of a strange noise.. Suddenly the tail shaft just drops right out on the footpath, nice as you like..

Pan head broke off inside the

Upon inspection i can immediately see it's the same bolt that broke in the front on the white car.. The now infamous 0109 "Pan Head (m2x8)", which this time now broke inside the 0085 "Active rear axle pinion" at the rear:

Pan head bolts.. why do you keep breaking?

The thing is, i can't see how these parts are loaded, moreover I don't think we were abusing the car.. It's not like we were doing jumps or whatever..  So I've now gone and ordered the 0085 "Active rear axle pinion" and some extra m2x8 bolts from Super Cheap Hobbies.

However I'm in the mind to drill these out to m3 and put a proper bolt in there..

 ..some days later i got tired of waiting for parts and I did exactly that.  First I had to drill out the grub screws to release the 0085 from the sub-assembly.  Then on the drill press I drilled out the old bolt with a 2.5mm bit, then tapped it out to M3.

0085 in the bench vice ready for tapping to M3

Then test re-assembled everything using an M3x8 hex head bolt, all good. 

The remnants of a grub screw next to the repaired assembly.

Finally all the bolts and grub screws were lock-tighted back in after final assembly.  Works a treat! and now i can await the delivery of the parts i don't need.