Broke my second diff outdrive today on my fourth run.

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stevedave

stevedave

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Arrma RC's
  1. Nero
I had all 3 diffs locked and hit a turn hard. Second time it's happened now, first time I thought it might have just been a poorly made part. Now I know it's not. Don't lock all the diffs and even dream about going fast, otherwise you're gonna break some stuff.
 
stevedave said:
I had all 3 diffs locked and hit a turn hard. Second time it's happened now, first time I thought it might have just been a poorly made part. Now I know it's not. Don't lock all the diffs and even dream about going fast, otherwise you're gonna break some stuff.
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yes...you are correct ..what you state is also in the manual...all diffs locked is not for high speeds. ..that warning is there...fast in blast mode all diffs open...fast in wheelie mode center diff locked. ..kinda fast in drift mode center and rear locked...all diffs locked is for crawling...

sorry dude...lots of inertial weight there. ..and we have pinged this topic on the board before...hate it happened...fix it and have fun the right way...

another thing...I hit a small jump..landed sorta kinda off angle and broke drive shaft and locked up another telescoping section of the drive shat on the opposite side...I didn't notice it...heated the outer bearing so hot that it melted the wheel hexes..did it twice before realizing bearing was heating up...I thought I didn't seat it...nero has so much power it wouldn't notice a boat anchor dragging behind...so strict throttle control on crawler mode..those aggressive blips can break stuff...
 
Look on eBay for your replacements. You can get a pair a complete driveshaft assemblies cheaper than 1 pair of outdrives or U-Joints. They are brand new take-offs.
 
Locking all the diffs basically turns it into a steamroller. when you turn, the outside wheel HAS to make more rotations than the inside wheel. if the diffs are locked, it becomes impossible and a ton of strain is put on the drive system.

This situation is universal for anything with wheels. even real 4x4 pickup trucks can and do break axles when all diffs are locked and are in a high traction environment.
 
there is a colorful description of modes and what to use them for with every new truck... full locked is for slow driving only!! you will break poop running around full lock.
 
Josh nortz said:
there is a colorful description of modes and what to use them for with every new truck... full locked is for slow driving only!! you will break poop running around full lock.
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Oh yeah definitely it's all on me no doubt about it. I thought I had switched them back to open, I was mistaken.
 
First five minutes out for the Christmas present and the screw pin broke that holds the driveshaft to the front outdrive.

Spares are far away at the hobby store... Can I just use a screw to see if it will hold? Assuming there is clearance for part of the screw head that sticks out?

Oh... And should I loctite this? I checked the other front screw and it was a bit loose... Not sure if it cam like that or loosened. It looks like while a lot of the screw is on metal, the threaded part is on the plastic ring.
 
Ekfchan said:
First five minutes out for the Christmas present and the screw pin broke that holds the driveshaft to the front outdrive.

Spares are far away at the hobby store... Can I just use a screw to see if it will hold? Assuming there is clearance for part of the screw head that sticks out?

Oh... And should I loctite this? I checked the other front screw and it was a bit loose... Not sure if it cam like that or loosened. It looks like while a lot of the screw is on metal, the threaded part is on the plastic ring.
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A regular screw won't do it, unless you find a nut and bolt that fits through there. If using a nut and bolt, ditch the plastic ring. Also double check that it clears the bulkhead.

I've broken 3, but never had one come lose. I did use blue loctite anyway on the ones I've removed.
 
I wonder if mine broke so readily because it was on diff lock and going quite fast...

Thanks for the tip. Will try to find a nut and bolt. Thought a screw would be the same since the screw pin is not bolted in.
 
Ekfchan said:
I wonder if mine broke so readily because it was on diff lock and going quite fast...

Thanks for the tip. Will try to find a nut and bolt. Thought a screw would be the same since the screw pin is not bolted in.
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that could be the source of the problem. ..it is best practice to come to a complete stop when switching between the different locking modes...

rolling and switching modes...that mistake is made quite often...so don't do it...

good luck dude. ..
 
Ekfchan said:
I wonder if mine broke so readily because it was on diff lock and going quite fast...

Thanks for the tip. Will try to find a nut and bolt. Thought a screw would be the same since the screw pin is not bolted in.
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Yeah. I would guess so. If you are going to drive fast I would leave it in blast mode. I broke a few rear pins in wheelie mode. Locked diff will put a lot of power to individual wheels and cause them to break.
 
Got replacement pins... Was going to lock tite but on inspection it looks like the threaded part of the screw pin only goes in the plastic boot.

Would assume ca glue would be better for this than loctite then?
 
Ekfchan said:
Got replacement pins... Was going to lock tite but on inspection it looks like the threaded part of the screw pin only goes in the plastic boot.

Would assume ca glue would be better for this than loctite then?
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I don't put anything on them. I haven't had one back out yet. I don't think gluing them to the plastic will stop it from breaking under extreme stress (i.e. locked diffs). I feel like the only thing gluing them will do is make it a PITA to take out when it does brake. I would just take the time to learn the limits of your truck with locked diffs. It's a lesson I am still learning. I have broken enough little small parts but I would happily take a broken grub screw over broken u joints. 6s is a lot of power and torque that needs to be respected...especially in a 14 pound truck. Just my $.02.
 
Depend of the weight of the truck and locked diffs, there is a lot of force on the lock pins.
if you are driving slow while you driving a curve, so the pins will damage a lot earlier than you lock the diffs while driving straight.
I do locking the gears always while driving slow and straight.
i do have also a 1:10 Axial Crawler with completely locked axels and with them i had more often problems with the shafts depends of the force between the axels an Motor.

I have my big rock since 3 weeks and i drive it very often. Till yet i have no damage on it. ...
Ok some scratches on the body and bumper but not mechanically damaging except one of the body holders was broken.
Maybe i am driving too slow, cause i drive just 4s offroad with the small gear.

Hope my bad english was understandable,
Regards,
lonee
 

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