e-maxx input shaft
 

what do people use to replace the weak rollpin on the input shaft of the e-maxx tranny, it's getting quite sickening, i have three tranny's sitting unusable due to a sheared rollpin, and i'm on my last tranny

I use a drill bit in mine and so do a lot of others. I've heard of other people using allen keys that they've sanded round.
I haven't had problems with the drill bit in mine, just make sure it's tight enough to not fall out.

i read an article in r/c car action and they say to heat the shaft and input gear in the oven, did you have to do all that or did you just shove the drill bit in? thanks for the quick response!

Yeah, I think I did try heating it. I remember it was a pain to put the new pin in though.

I used a hex key that was just too big and pressed it in with a bench vise. Should hold up alot better than the rool pin.

I just replaced the input shaft for $2.50.

Your new one will still have the roll pin though won't it. So it dosen't make the transmission any stronger.
My pin hadn't broken yet, but I replaced it with the drill bit when I went brushless, because I knew it wasn't going to last that long.

Get some permanant lock tite. I use the Red kind.

Dab a little on each end of the pin, then dab some on the input shaft between the gears. I usually do one gear at a time, then stand the shaft on it's end in a vise to let it soak in until it dries. Then turn it over and do the other gear.

Don't apply any on the outside of the gears or it will interfere with the bearings.

Yes, a new one will still have the weak roll pin.

I think alot of the potential weakness comes from using reverse alot. As well, as the extra BL power.

I dont you reverse very much at all now and the shaft is holding up just fine.

I am sure the main issue is caused by the slack that exists between the sliding coupler and the output gears. When you use the brakes the motor stops, as do all of the gears in the tranny. The coupler can rotate as much as 60 degrees before it engages the output gear. This shocks the gear train in the tranny and that weak roll pin takes a hit. After time this will eventually break it. Also with high power brushless and grippy tires the roll pin is simply the weakest part, especially if you have the slipper set tight.