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SuperHornet

Lunchbox Issues

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after a few weeks of bashing... not really more than like 20 minutes of medium running like evry other night Im getting a really loud clicking noise coming from the gearbox, seems to be louder when I reverse.. closer inspection revealed nothing, put back together.. still the same sound. Anyone have any exp like this with this gearbox?

ps the box is 100% stock

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Sounds like your pinion has gone to me. The teeth should look like this /\ and not like this /l. If they do its why the noise is louder in reverse. ;)

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Wear on the brass pinion would be unusual. I have over 150 packs through mine with the 5700Kv pushing on it and no visible wear. No wear on any of the gearbox or diff gears infact.

Plastic bush worn would allow the idler gear to move. For the $12 cost of a bearing set for it, it's well worth it. Stripped screw would allow the box to seperate under load.

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are you sure it's the gearbox and not the motor? what surface do you run on?

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I'd take a closer look at the motor. I've had pebbles get into the vent holes on motors before and cause noises. And sometimes you catch a pebble that has enough iron in it that it sticks to the motor magnet, so it won't work its way out.

If you didn't see any obvious problems in the gearbox, it's probably fine. As long as you have ball bearings in it, and everything's assembled properly, it's more or less indestructible.

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Well I found the issue and I cant believe it escaped me the first time. I have attached a picture of it, I dont know the name of the gear, I have to look in my user manual.

The teeth are chewed in a few spots along this gear. photo.jpg

Im kind of upset about this, since I thought I put this thing together well... apparently not. I cant imagine what went wrong, maybe the actual gear on the motor was pushed too far out? have no idea. Either way I need to figure out what the cause of this problem was before I buy more gears and just chew through them too. I ran the lunchbox about 2 dozen or so times since I got it, and mostly on the street, but also various other terrain like rocks sand mud snow the beach... did a few jumps under 2ft, nothing crazy.

do they sell beefier versions of this gear?

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Ouch! It's the spur gear, runs off the pinion. First time I seen one that looks like that with this gearbox. I have a massivly powerful motor in mine with a lot of heavy use and not had this happen, and I have the ESC turned up full too. One thing my ESC won't allow is forward straight to reverse like a MSC or boat ESC will.

You need to splurge on some bearings. Bushes are for shelf queens.

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If you don't have bearings, and it wasn't greased properly the drag on the gears could cause it to slip under the pinion. Happened on my Hornet when I was a kid, at the time 8 for new gears was a month's pocket money! ;)

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If you don't have bearings, and it wasn't greased properly the drag on the gears could cause it to slip under the pinion. Happened on my Hornet when I was a kid, at the time 8 for new gears was a month's pocket money! :)

could too much grease cause this issue?

my esc is stock so its not forward to reverse instantly

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Yeah, too much grease can be just as bad as not enough...especially if it gets dirty, water in it (emulsifies) etc.

its clean though, no dirt or water in the case... I have a super hornet (which im going to be selling soon) I never had an issue with the gearbox. Theres got to be something wrong im doing, maybe the pinion positioning is wrong or could it be that this happened during a jump.. maybe the wheels spun too fast while airborne and came to an abrupt stop coming down and screwed up the teeth? shouldnt the diff prevent that?

Im going to pick this up, its pretty cheap

tower hobbies

do they sell alloy versions?

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Check your motor mount is assembled right. If one of the M3 nuts isn't in where it should be, it could cause that. The through bolts would both pass into the motor mount, and stop the motor swinging in and out of mesh, but it would not stop it flexing outways if only one through bolt was holding it in.

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Those are too long for the Lunchbox, the ideal setup is something around 80 -85 for the front & 90ish for the rears :)

Lots of people end up with 5 shocks on their machines, eg:

My Munchkin

Mymonsterbeetleisbroken

Skip665's

thanks for the awesome links

the kit says the shocks are 80 all around, any reason for the 90mm in the back?

I was thinking of picking these up

rcmart

and the 90mm version if I need, also which shock should I use for the 3rd shock mod?

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You can go with slightly shorter fronts & 80's in the back, the idea is to give it a nose down stance, by doing so it improves the handling.

There's room for experimentation, mine has 90's in the back & handles pretty well (for a Lunchkin chassis that is :) )

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You can go with slightly shorter fronts & 80's in the back, the idea is to give it a nose down stance, by doing so it improves the handling.

There's room for experimentation, mine has 90's in the back & handles pretty well (for a Lunchkin chassis that is :) )

ok cool

so im going to pick up the 80mm for the front the 90mm for the back and the new gear, then I should be rolling again

maybe the dampers will make the jumps a little more forgiving

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Also one more, Ive noticed the term "fully ball raced" when reading about some gearboxes, what does it mean specifically and is it possible to do this to a lunchbox?

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Thanks for the plug mate :)

Indeed, it's hard to believe but that rear deck can snap as the chassis gets older and more flexible.

Spur gears snapping teeth doesn't happen often, hopefully a rebuild with ball bearings and a new gear will sort it out.

Like a few others, I've got a stupidly fast motor and have found the gears love it :D

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