Outcast Arrma Outcast rear diff

[ruizjunior83]

I just got this rc two weeks ago and believe the rear diff went out a bad landing. So I’ve changed everything Internals, spiral gear, and input shaft and soon as I hit mid throttle a loud clack happens and there go the teeth. 4 gears already.
I added a shim to the one outside by the bearing that was already there to see if that helped. And nothing. The oil is 50/100/10. I don’t know what else to do.

 

[WoodiE]

@ruizjunior83 what kind of batteries are you using?

 

[ruizjunior83]

2 Lectron 3s 50c 5000mah. I do have punch at 9. Could that be it? But I haven’t floored it. Most half throttle and that’s when the clank happens

 

[Camo]

Have u had the diff apart ? Sounds weird bro !!!
I have beat mine to death and only ever busted a planetary gear. The input cup might have come loose ?? Or broke a tooth on the pinion ??

 

[ruizjunior83]

I took diff apart. I keep breaking teeth on the big spiral gear and input gear. I don’t know what else to do. Would over threading the screws on the housing cause it? Two screws get tight but two just keep turning.

 

[olds97_lss]

Sounds like bad shimming and possibly a bad bearing or two. Did you check your pinion and diff bearings as well? Usually, if I'm going through the effort of installing a new diff, I replace the bearings as well just to know I have good ones. With spiral gears, pretty sure you have to shim them to have nearly no gear lash. Each diff/case will be different, so 1 shim for one guy may mean 2-3 shims for you, or none. You may even have to shim the pinion to push it closer to the center of the ring gear.

Might be a good idea to closely inspect the gear case as well. Perhaps it has cracked and you don't see it when not under load. When torque is applied, a cracked case will spread and your mesh will suffer.

 

[Hunter Reynolds]

Sounds like the pinion gear that drives the rear diff. I have had one go bad on me and it made the same sound your discribing. It could be worn or maby it needs a Shem behind it but that is what it sounds like to me

 

[ABRedneck]

Plus, if you have two stripped threads, they aren't holding things together.
The case probably spreads & the gears become misaligned.

Add that you have the punch set at 9 and I think that's the answer.
Nobody controls the throttle 1/2 way, eventually in the first 15 seconds, you'll punch it.

Maybe you can find longer bolts and nuts to bold the housing...
Or maybe just get the next size screw, and make new threads...

Good luck with it!
I know it sucks doing more repairing than driving, most times...
RJP

 

[ABRedneck]

Sorry Olds...
You beat me to the cracked case possibility.
But, if he has two stripped holes outta 4, I'm sure the gear mesh, pattern, misalignment,
whatever you wanna call it, I think it's happening!

Have a great weekend Olds!!
RJP

 

[olds97_lss]

Sorry Olds...
You beat me to the cracked case possibility.
But, if he has two stripped holes outta 4, I'm sure the gear mesh, pattern, misalignment,
whatever you wanna call it, I think it's happening!

Have a great weekend Olds!!
RJP

Yeah, I didn't catch that last response he made before I posted. Stripped screws will definitely cause a problem and make the case weaker as a whole. Alloy cases are best, but in lieu of that, good bite from the screws is a must.

With my old savage's, pre-x, they had a bit of flex in the diff cases so many people would upgrade to alloy housings for the entire diff to sit in which allowed for consistent shimming/gear mesh. These days, the cases are more robust, even if plastic and looking at the arrma cases, alloy isn't a necessity, but good screw threads are.

 

[Raji]

I just got this rc two weeks ago and believe the rear diff went out a bad landing. So I’ve changed everything Internals, spiral gear, and input shaft and soon as I hit mid throttle a loud clack happens and there go the teeth. 4 gears already.
I added a shim to the one outside by the bearing that was already there to see if that helped. And nothing. The oil is 50/100/10. I don’t know what else to do.

I'm in the same shoes here with my outcast. I stripped three I think tell now ( MAIN INPUT GEAR 10T SPIRAL (1PC) #AR310498 )
we keep striping it because of the back flips. Reduce the punch sitting also. I really like the Outcast in punch sitting 9, but that will eat your drive train

 

[ruizjunior83]

Is there an aluminum housing that won’t sacrifice the sway bars?