Team Losi JRX / LXT Series Retrofit XXX Gear Diff Transmission Case/Hinge Mount

thingiverse

Retrofit gear box to allow for the use of XXX-SCT drivetrain in older Losi vehicles that are equipped with the LRM transmission (JRX2, JRX-Pro, JRX-Pro SE, JRXT, LXT, Junior 2, Junior T). PLEASE NOTE - CHASSIS MODIFICATION IS REQUIRED to get this to fit. I personally have always liked the LRM transmission. While I tended to run mine quite tight, I never had any issues with it. It seemed, in my opinion, to be better than the retrofit transmission when I raced (just seemed to spool up quicker). That being said, with the introduction of more widely available brushless systems, it may not always be up to the task of handling that kind of power. This was a bit of a "seeing if I could do it" project - but this uses the original retrofit transmission kit as inspiration to allow for the use of the XXX-SCT gear diff. NOTE: 1. VERY IMPORTANT AND MAY MAKE YOU NOT WANT TO DO THIS!!!! You will have to increase the chassis pocket slightly to account for the larger gear diff than the standard retrofit ball diff. I am not super wild about this aspect of the design - so I may revert this back to a ball diff. That would also allow for the use of the original slider driveshafts. The gear diff is wider, and just does not package that well. I did look at spacing it up higher (and may still try it) - but I was concerned with dogbone length. 2. The rear hinge mount has to be widened so a 3D printable version is included. It is the standard recommended kit version (antisquat/toe-in). 3. You will need a set up XX or XXX dogbones (for either the buggy or truck), XXX upper slipper shaft/gear, XXX idler and XXX SCT gear diff to complete this. You can use your older LRM motor plate. You'll need to pick the appropriate 4-40 hardware to complete. This is still a work in progress and more a proof of concept - I would like to dial in some of the clearances a little bit (relative to the rear bulkhead), overall heights to match printer resolutions, add some features to improve printability, and create a dust lip around the entire perimeter. Long term, I may model the original XX retrofit "box" as it's not that far off from this (different diff gear, but other portions of the design could likely be retained. It would also be a better fit with the existing chassis.