Axial overdrive gear fitment for E10

[Smokin' Joe]

Here is some info for anyone wishing to add axial's overdrive gear (AX30401) to your E10's front axle. I have fit the gear in, but haven't yet used it.

One place where fitment is an issue is attaching the locker housing to the gear. The stock plastic locker housing needs to be ground down slightly in order to attach to the gear. If you have the upgraded aluminum spool (180009), it attaches without modification.

The other area where fitment is an issue is with the included pinion gear. The pinion gear does not have a flat spot for the stock drive shaft's set screw to attach to. Instead it has a 2.5 mm hole for a pin. The included pin doesn't work as the threaded area is 3mm instead of 4mm. I attached mine using a Traxxas pin (TRA5145). I then drilled a hole through the far side of my drive shaft to allow the pin to come all the way through. You may also need 5mm shims to place the pinion gear properly to smoothly interface with the ring gear.

I'll update this post if I run into any other issues after running the truck as well as impressions on the upgrade.

[hillbillyrc]

Axial shafts would work also. And if the overdrive gear fits then you can underdrive the rear axle which will help with torque twist also.
https://www.amainhobbies.com/axial-r...FU2SfgodJ6wN2g
I was pondering this mod the other day glad someone tried it.

[Bronco RC Crawler]

Interesting write up. I've been wondering lately about e10 and scx10 gear compatibility. Been thinking about adding some boom phat axles to my e10 specifically.

[Smokin' Joe]

"Axial shafts would work also. And if the overdrive gear fits then you can underdrive the rear axle which will help with torque twist also.
https://www.amainhobbies.com/axial-r...FU2SfgodJ6wN2g
I was pondering this mod the other day glad someone tried it."

Replacing the drive shaft was one of the options I considered. Most of the well recommended upgrade options are fairly expensive and some would require a different pin anyways so I decided to stick with my stock drive shaft for now.

Overdriving the front is fairly equivalent overall to underdriving the rear. The main difference is you'll end up with a slightly higher speed with the overdriving option and you'll keep the same speed with the underdriving option. Keeping the speed a little lower and going with the underdriving option would reduce torque twist slightly. You could do both if you want an even larger gear spread, but I figured I'd start with one gear for now. I wanted a little higher top speed so I went with the overdriving option. Also I can't guarantee fitment of the underdrive gear as it will be a little bit larger gear. I do think it would likely fit though.

[Smokin' Joe]

Update. Finally got my truck out to play briefly. Initial impressions are very good. Had a noticeable increase in speed and in turning radius. I didn't have too much opportunity to test an increase in climbing ability, but what I saw looked good. I have a rock on my backyard course with a significant break over that I hadn't been able to get over with my current suspension setup. Went two in a row getting over it with the overdrive gear in place.

[Smokin' Joe]

Update. I added an underdrive gear to my rear axle. Fitment is the same as described for the front axle overdrive gear.

[Smokin' Joe]

Update. Took my E10 out to my local hobby shop's crawler course. Very noticeable improvement with both under and overdrive gears installed. It seemed to turn quite a bit sharper. It also seemed to climb better though the effect was less noticeable than the improvement in steering. Wish I had done this sooner.

[hillbillyrc]

Good to know I plan to overdrive my front. Already underdriven the rear.