Volcano 16/ SG 1602 / HBX 16889, 16889a Pro, etc are all Shenzhen made trucks, the Shenzhen RC plant is MAAASASIIIVE!
And makes things under brands like Hobbywing, Surpass, WLToys, XK, HAIBOXING, HBX, and on and on.
The best write up I have found about these cars is by the now legendary QuadifyRC dot com.
I Ordered the differential outdrives and realized you must order the "metal gear diffrential upgrade" in order for your metal diffrential outdrives to fit. The stock plastic outdrives attach to the plastic gears inside the diffrential completely differently as do the metal rear dogbones amd metal front CVDs. So, to get your transmission "brushless ready" from a bone stock plastic model you must order:
1. metal spur gear (amazon super cheap)
2. Metal pinion gear w/grub screw (amazon cheap)?
3. Metal dogbonez & CVDs with wheel hub axles aka stub axles (ebay super cheap)
4. Two sets of metal diffrential gear upgrade kits (amazon expensive but definitely gonna get them, or Walmart online super cheap but may or may not receive them :-/ , if anyone finds a source for a pair at good price in the states please post)
5. Metal center driveshaft with bevel gears (although my HBX has a metal center driveshaft it is not compatible with the diffrentials after they have been upgraded with the meatal gear upgrade kit. Amazon fair price and fast shipping)
6. Wheelie bar (if your model doesn't have one you will need one after going brushless, Amazon cheap for Volcano 16 or HBX 16889 models)

I also grabbed the dark blue Aluminum parts upgrade kit off Walmart online for less than $30 and it includes the upper and lower A-arms as well as all 4 hubs and the front C-hubs and the steering parts including the Ackerman bar. Hellof a kit. I dont usually buy aluminum lower A-arms for any of my RCz but buying the parts in this kit separately is mega expensive so i just got the combo. I also ordered an HBX 16305 Red Truggy body because....well.....y not, its awesome looking!
Finally i got a set of Traxxas mini Erevo wheels and tires for it because they are much much better teaction and they last much longer.

I hope any of this helps someone, no one knows everything but together we can know almost all of it!
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