Motor looks crooked, plus high-pitched noise at full throttle

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Arrma RC's
  1. BigRock
I have a Big Rock V3, purchased right at the start of 2021. Ever since buying it, the motor has sat somewhat crooked on the mount. Is this normal? The two gears in the mesh (excuse terminology) are aligned.

The other day I was running the truck and at full throttle (75% power) I noticed a high pitched noise that I don't recall hearing before. I took the motor off the mount and adjusted the mesh best to my ability (it seems good, based on examples I have seen).

Would something with the motor sitting crooked cause the high pitched noise to develop over time? Unfortunately it has been raining nonstop so I haven't been able to take the car out for a test after making the recent mesh adjustments. It didn't seem to happen (or wasn't as noticeable) when I was holding the truck in the air and letting the tires spin.

bigrock-chassis.jpg
 
Is the motor mount bent(?) That's what it looks like. Happens sometimes when collisions with solid objects happen.

Or maybe your motor mounting screws are not mounted properly(?) I loctite mine. Do you have an adjustable motor mount(?) It is slotted for those screws.
 
That is more than “somewhat crooked” and it’s probably destroying your spur gear as you run it. Get a new motor mount and spur. Might want to check the pinion and motor bearings as well.

Bent motor mounts usually happen when crashing into something at speed.
 
Thank you both. I'll take the mount apart today to see if it is bent and I'll order replacements if that's the case.
 
Killed my spur gear. The pinion and motor bearings were fine. It was months later my motor bearing went so it was probably unrelated.

That crash also split my chassis under the front diff.
Lost radio contact. Have since replaced the STX2 that came with my truck. Stupid thing cost me a lot of money. Unreliable radio=devastating crashes
That was the stock motor mount
I wanted to replace it with an adjustable one anyway. Never tried to bend it back. I figured it has to be true to work well.
 
So I took the mount apart and it was indeed bent pretty bad and resembled the pic that Freelander posted. I ordered a new one. How can I tell if my spur gear has been affected? Visually it looks fine and spins great. Should I try the new mount and see if the noise is still present?
 
The OP's picture clearly shows a BENT motor mount.:LOL:

"Mission Control...we have a problem...":ROFLMAO:

Hopefully M2C gets their Motor mount support (the FIX) released soon.
 
Just check if there is play on your motor shaft. There should be none.

Otherwise your motor bearing might be fiddlesticked.

You'd probably know if your spur gear is roasted. There would be plastic shaving everywhere inside your power module.
 
Just check if there is play on your motor shaft. There should be none.

Otherwise your motor bearing might be fiddlesticked.

You'd probably know if your spur gear is roasted. There would be plastic shaving everywhere inside your power module.

Thanks. The motor shaft feels fine. There's no play.

Here are some additional photos. I have a new plate assembly on the way. I hope that fixes me up for a while.

spur-side.jpg


spur.jpg


motor shaft.jpg


mountplate.jpg
 
Dam ...$70..... HC
M2C knows that it is the only fix out there. They got a lock on it . Can charge what they want,
The 4x4 rigs are so costly to upgrade. For mere Fixes that Arrma wont address. Known issues out the box. 4x4's are more costly to own IMHO. Cheap to buy. That's all.
That's why I stay with the 6s line. 🤷‍♂️
To fix many issues with the 4x4's, Bling upgrades aside, you can easily double the cost of a 4x4.


EDIT:
I know the 4s 4x4's soon to be released have some tweaks to prevent some of those issues. Will they work?' It's anyone's guess.
I know the 4s motor will have a rear brace to keep the back of the motor in check, for starters.
 
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I dunno dude. Spur and poop looks fine. Looks like you stopped or couldn't run long enough to mangle more poop.

Lucky!

That bent no wonder you weren't going anywhere!

Yeah, bro. I would try and straighten it. Why not? Easy to check if it is good really. Hope you have a vice. Just be careful to get it as straight as possible so you don't fiddlestick up your motor trying to save a 20 dollar part if you know what I mean.
 
You can hack it and use a sledge hammer over a block of wood. BUT it will NOT be straight ever again. And the alloy will get weaker with bending it back. Will bend again even sooner.
Eat it, like I would. $20. . Might as well buy 2, one as backup while you are at it. May bend again sooner or later. Or just buy one more and a $70. (ouch) M2C mount support. ($90. total) Better order it ASAP from M2C. They will be flying out the door and go on B/O quick.
Why risk gear alignment. Never do that.
 
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The OP's picture clearly shows a BENT motor mount.:LOL:

"Mission Control...we have a problem...":ROFLMAO:

Hopefully M2C gets their Motor mount support (the FIX) released soon.
It's out already, there's a You Tube video on it, $70.00
 
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