Mojave Can't get the pinion off

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Mdgaming

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Arrma RC's
  1. Limitless
  2. Kraton 6s
  3. Mojave
my pinion gear has slipped over the motor shaft so it's no longer touching the diff gear. The problem is however that I can't get the pinion to slide over de Shaft any further and the grub screw is stripped(arrma has gone a little nuts with the amount of thread lock I think).

Any tips on how I can get it off? If possible without destroying the gear but I'm not afraid of killing it.
 
Have to use a good amount of heat to break the loctite loose..

If the hex is now stripped you can do one of several things...

Use torx bit, find one that almost fits... rest the pinion on a block of wood, set the torx bit up so every 2 splines lines up with the original flats of the hex... give the torx bit several sharp hits and drive it into the grub.. make sure it has made it to the bottom of the hex... after that, heat the pinion up good and unscrew the grub.. at that point toss it, replace with a new one... while it's hot remove the pinion from the shaft as well so you can clean it up and inspect the shaft..


Option 2, you can setup a jig that holds just the pinion, a slot in a stout piece of metal you can slip it in to support the back side of the pinion.. because it spun on the shaft you can leave the grub alone... find a nice punch that fits square on the end of the shaft and drive the shaft and motor out of the pinion bore.. then back to the torx bit method to remove the grub after the pinion is off the shaft.

Option 3 is drill the grub, but this leaves you no solution besides replacing the pinion and grub..

Option 4 is take a cut off wheel, very thin like the ones for a dremel.. cut a slot across the grub deep enough to use a small flat head screwdriver to engage the grub... lots of heat and try to unscrew it... will still be at the cost of a pinion and grub...

Option 5 is use the cutoff wheel to slice a groove through the length of the pinion almost to the shaft.. (don't go all the way to the shaft or you will cut into it) once you have your slot cut rest the pinion on something solid like a block of wood, use a tapered chisel, rest it on the slot you cut and give it a sharp hit... it will split the pinion and relieve the fit from the shaft.. again rendered useless and will need replacing...

Hope this helps
 
Only problem with option two is the flat on the motor shaft does not go to the end on the blx motor. If the screw has back off enough it still may work. Once that screw gets boogered up it’s a mess to get out.
 
Only problem with option two is the flat on the motor shaft does not go to the end on the blx motor. If the screw has back off enough it still may work. Once that screw gets boogered up it’s a mess to get out.

Excellent point, I forgot about that... good catch brother...
 
Have to use a good amount of heat to break the loctite loose..

If the hex is now stripped you can do one of several things...

Use torx bit, find one that almost fits... rest the pinion on a block of wood, set the torx bit up so every 2 splines lines up with the original flats of the hex... give the torx bit several sharp hits and drive it into the grub.. make sure it has made it to the bottom of the hex... after that, heat the pinion up good and unscrew the grub.. at that point toss it, replace with a new one... while it's hot remove the pinion from the shaft as well so you can clean it up and inspect the shaft..


Option 2, you can setup a jig that holds just the pinion, a slot in a stout piece of metal you can slip it in to support the back side of the pinion.. because it spun on the shaft you can leave the grub alone... find a nice punch that fits square on the end of the shaft and drive the shaft and motor out of the pinion bore.. then back to the torx bit method to remove the grub after the pinion is off the shaft.

Option 3 is drill the grub, but this leaves you no solution besides replacing the pinion and grub..

Option 4 is take a cut off wheel, very thin like the ones for a dremel.. cut a slot across the grub deep enough to use a small flat head screwdriver to engage the grub... lots of heat and try to unscrew it... will still be at the cost of a pinion and grub...

Option 5 is use the cutoff wheel to slice a groove through the length of the pinion almost to the shaft.. (don't go all the way to the shaft or you will cut into it) once you have your slot cut rest the pinion on something solid like a block of wood, use a tapered chisel, rest it on the slot you cut and give it a sharp hit... it will split the pinion and relieve the fit from the shaft.. again rendered useless and will need replacing...

Hope this helps
I will try a few of these options, see which works. Thanks for going into so much detail and giving so many options.
 
Heat via a good soldering iron (or a mini torch with a tight flame) and torx bit jammed in there would be my approach...

heat is key though, seriously get it hot (within reason here lol).
 
Well I tried a few different options you gave me, ended getting the Dremel out sadly. Even with the pinion at well over 100°c it wasn't coming out. The motor mount screw however did come out with a lot of heat.
 
Well I tried a few different options you gave me, ended getting the Dremel out sadly. Even with the pinion at well over 100°c it wasn't coming out. The motor mount screw however did come out with a lot of heat.


Is what it is brother, at least it's off and you can move forward and get back up and running... (y)
 
Is what it is brother, at least it's off and you can move forward and get back up and running... (y)
Indeed, whatever needs to be done to get it going again right! Luckily a new pinion and a set of screws won't set me back hundreds of euro's and are readily available at my lhs(gives me a reason to go and have a look at the new cars they got aswell)
 
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