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Re: Thorp Dirt Burners Losi JRX2 LRM Gears
Posted: Tue Nov 15, 2022 5:43 pm
by Nige55
BattleTrak wrote: ↑Sun Aug 28, 2022 9:18 pm
The Thorp Delrin top shaft gear also fits properly on the Losi A-3120 Hydra-Drive/Slipper shaft. Which means it will also fit the A-3007 JRX-Pro top shaft and the A&L Power Clutch shaft.
I've just done this exactly after I received the topshaft and delrin gear today. However it binds when I tighten the gearbox fully. Did you need to grind any gearbox inner? I notice my Thorp gear is marginally wider than the stock gear for that topshaft.
Re: Thorp Dirt Burners Losi JRX2 LRM Gears
Posted: Wed Nov 16, 2022 6:30 am
by BattleTrak
Nige55 wrote: ↑Tue Nov 15, 2022 5:43 pm
BattleTrak wrote: ↑Sun Aug 28, 2022 9:18 pm
The Thorp Delrin top shaft gear also fits properly on the Losi A-3120 Hydra-Drive/Slipper shaft. Which means it will also fit the A-3007 JRX-Pro top shaft and the A&L Power Clutch shaft.
I've just done this exactly after I received the topshaft and delrin gear today. However it binds when I tighten the gearbox fully. Did you need to grind any gearbox inner? I notice my Thorp gear is marginally wider than the stock gear for that topshaft.
No, I didn’t have to grind anything.
A few things to check:
- Make sure the roll pin is centered or not too long to where it is interfering with the gear mesh.
- Make sure the hole for the top shaft in the gear case is 5/16” so that it doesn’t rub the slipper plate.
- Last, be sure to install a shim on the end of the top shaft…#69 in the pic.

Re: Thorp Dirt Burners Losi JRX2 LRM Gears
Posted: Wed Nov 16, 2022 6:47 am
by Nige55
BattleTrak wrote: ↑Wed Nov 16, 2022 6:30 am
Nige55 wrote: ↑Tue Nov 15, 2022 5:43 pm
BattleTrak wrote: ↑Sun Aug 28, 2022 9:18 pm
The Thorp Delrin top shaft gear also fits properly on the Losi A-3120 Hydra-Drive/Slipper shaft. Which means it will also fit the A-3007 JRX-Pro top shaft and the A&L Power Clutch shaft.
I've just done this exactly after I received the topshaft and delrin gear today. However it binds when I tighten the gearbox fully. Did you need to grind any gearbox inner? I notice my Thorp gear is marginally wider than the stock gear for that topshaft.
No, I didn’t have to grind anything.
A few things to check:
- Make sure the roll pin is centered or not too long to where it is interfering with the gear mesh.
- Make sure the hole for the top shaft in the gear case is 5/16” so that it doesn’t rub the slipper plate.
- Last, be sure to install a shim on the end of the top shaft…#69 in the pic.
Perfect! Thank you!! I realise from your post I don't have the shim there at the end of the shaft. Thank you, I'll try adding that
Re: Thorp Dirt Burners Losi JRX2 LRM Gears
Posted: Fri Nov 18, 2022 6:36 am
by Nige55
BattleTrak wrote: ↑Wed Nov 16, 2022 6:30 am
Nige55 wrote: ↑Tue Nov 15, 2022 5:43 pm
BattleTrak wrote: ↑Sun Aug 28, 2022 9:18 pm
The Thorp Delrin top shaft gear also fits properly on the Losi A-3120 Hydra-Drive/Slipper shaft. Which means it will also fit the A-3007 JRX-Pro top shaft and the A&L Power Clutch shaft.
I've just done this exactly after I received the topshaft and delrin gear today. However it binds when I tighten the gearbox fully. Did you need to grind any gearbox inner? I notice my Thorp gear is marginally wider than the stock gear for that topshaft.
No, I didn’t have to grind anything.
A few things to check:
- Make sure the roll pin is centered or not too long to where it is interfering with the gear mesh.
- Make sure the hole for the top shaft in the gear case is 5/16” so that it doesn’t rub the slipper plate.
- Last, be sure to install a shim on the end of the top shaft…#69 in the pic.
Thanks again for the help! Weirdly it's still binding. looking at the metal stock gear on that shaft, it doesn't protrude past the pin (the pin sits in a recess for it), whereas the Thorp one does. So I may just try sanding it down on the pin side.