Mojave Diagnose this Sound?

[DTW]

Hey,

During a relatively mild bashing session my Mojave began making a very loud screeching noise. The clip doesn’t do it justice on how loud/grating it is. When lifted off the ground the noise mostly goes away. Any idea whats going on? There are no rocks/grim stuck in any moving parts that I can see.

Very short clip of the noise. Can take another video if needed.

Thanks,
Dennis

 

[dure16]

Gear mesh might be too tight. Perhaps the motor shifted closer to the spur on a hard landing.

Otherwise could be a blown bearing.

 

[3d-rc.myshopify.com]

Sounds like a lot of slipping there. I would definitely check the front and rear differentials. It sounds like it’s completely rounded over the teeth.

 

[Sandracer_NL]

Sounds like broken diff teeth.

 

[Tex Koder]

Pinion gear(its grub screw) came loose?

 

[SrC]

First check the motor's pinion gear like stated above.... for proper mesh/ loosened grub screw??? The obvious first.
But it sounds like one or more of your Main gear/ Input gears are stripped, worn or chipped. Probably need to replace the Main/Input gears as Sets now. No undoing that sort of damage. JennysRC has complete diffs/bulkheads for the least Coin. Still need to rebuild it. Don't just plop it in. You will be at square one again soon. I feel my Mojave is the least needy when it comes to diffs overall compared to my other 6s Arrma rigs. They last so much longer as an Offroader rig. But I never jump my Mojave. Only my other rigs.
Proper shimming and lube would have prevented it. IDK. Not sure what it is there until you open it up. I would open the Rear first. Usually they go first from my experience. Start there.
But after about 15 runs, diffs need a rebuild or at least a minor tear down to keep them in good shape. If you never opened your diffs and checked for diff oils and proper shimming, now you know. Most Diffs out the box are not set up properly anyway. Often underfilled and poorly shimmed. They fail much earlier than if if you built it yourself when new out the box. I learned the hard way also with my First OC many years ago. It is not truly RTR out the box.
Need shims always on hand in your toolbox. One or 2 as needed. I rather have a tighter than looser mesh. ( Arrma 6s diffs)

 

[oregoncoastrc]

First check the pinion gear like stated above.... for proper mesh/ loosened grub screw??? The obvious first.
But it sounds like one or more of your Main gear/ Input gears are stripped, worn or chipped. Probably need to replace the Main/Input gears as Sets now. No undoing that sort of damage. I feel my Mojave is the least needy when it comes to diffs overall compared to my other 6s Arrma rigs. They last so much longer as an Offroader rig. But I never jump my Mojave. Only my other rigs.
Proper shimming and lube would have prevented it. IDK. Not sure what it is there until you open it up. I would open the Rear first. Usually they go first from my experience. Start there.
But after about 15 runs, diffs need a rebuild or at least a minor tear down to keep them in good shape. If you never opened your diffs and checked for diff oils and proper shimming, now you know. Most Diffs out the box are not set up properly anyway. Often underfilled and poorly shimmed. They fail much earlier than if if you built it yourself when new out the box. I learned the hard way also with my First OC many years ago. It is not truly RTR out the box.
Need shims always on hand in your toolbox. One or 2 as needed. I rather have a tighter than looser mesh. ( Arrma 6s diffs

case in point on the diffs not bring truely rtr: i just took apart an rtr exb diff that had the equivalent of about 3 drops of oil in it and the lsd plates were installed upside down.. the sucker had thankfully never been run.

 

[SrC]

Good man, you know the dealio.
I have had HH send me oil numerous times before. I have like 3 dozen bottles of diff oil here anyway . On principal, I want HH to know they are cheap by not filling their diffs up. I paid for proper oil to be in there per the manual. They oblige, because they know that "I know" they do this with their rigs, a pattern over the years., NIB.
If you say nothing, HH hoping you won't notice and expect you to buy parts that failed early because of poor Factory assy. I bet 90% of their rigs sold, this happens to the buyer. I could see how a first time Arrma buyer would give up on Arrma easily due to frustration. The seasoned Arrma guys figured it out. After getting burned with their first Arrma rig. All my new Arrma rigs( any RTR brand) get rebuilt out the box before running them.
I find many stripped parts. PB nuts cross threaded, Wheel nuts over torqued, wheel alignment all jacked up. Tires poorly glued, Diffs poorly shimmed if at all, underfilled, pinion gears poorly meshed, I had a poorly stamped twisted Limitless chassis, Diffs that were locked up, diffs that had foreign metal in there chewing up the sun gears, I could go on and on. I let HH know and they easily oblige and replace parts. Sometimes as much as $250+ in parts. ( My Lim)
I am an old fart kit builder, so nothing goes past me with RTR's.

 

[JustAnOutcast]

Hey,

During a relatively mild bashing session my Mojave began making a very loud screeching noise. The clip doesn’t do it justice on how loud/grating it is. When lifted off the ground the noise mostly goes away. Any idea whats going on? There are no rocks/grim stuck in any moving parts that I can see.

Very short clip of the noise. Can take another video if needed.

Thanks,
Dennis

Dang. Mine was making a similar racket after a 3x diff service. Thankfully it went away after some mild jumping. I’m still spooked now and may tear them apart and have a look…
My guess would be something in your diffs is slipping.

 

[oregoncoastrc]

i didnt know they would do that! how do you contact them typically? I have an esc i need to send it for cogging and outside of filling out their online form for repair I’m unsure how to go about it. they hide the phone number on the site, probably for a reason, but I’d like to talk to someone to get a better idea of what to do/what they actually need for a warranty repair. When your new rtrs have issues do you call them, or use the online form and wait however long they want to take to respond?

 

[slick2500]

i didnt know they would do that! how do you contact them typically? I have an esc i need to send it for cogging and outside of filling out their online form for repair I’m unsure how to go about it. they hide the phone number on the site, probably for a reason, but I’d like to talk to someone to get a better idea of what to do/what they actually need for a warranty repair. When your new rtrs have issues do you call them, or use the online form and wait however long they want to take to respond?

1-888-959-2307
I also see 1-877-504-0233 listed. Not sure which one works.

 

[SrC]

Not sure if this HH # works still. Give it a try. I believe this was their Tech Support number. Not the Warranty dept. But I always got service from them.

888-959-2307

I haven called them in a while. My early released TLRT Typhon last Nov. was actually in perfect condition except for the stripped plastic front chassis brace. I was replacing with EXB alloy anyway.. A first Arrma for me that actually was "close" to perfect. Even the diffs were topped off and shimmed. I was like what??? Happy to say at the least. Had to be fluke!!!

@slick2500 beat me.

 

[oregoncoastrc]

Not sure if this HH # works still. Give it a try. I believe this was their Tech Support number. Not the Warranty dept. But I always got service from them.

888-959-2307

I haven called them in a while. My early released TLRT Typhon last Nov. was actually in perfect condition except for the stripped plastic front chassis brace. I was replacing with EXB alloy anyway.. A first Arrma for me that actually was "close" to perfect.

@slick2500 beat me.

You and @slick2500 rock!

1-888-959-2307
I also see 1-877-504-0233 listed. Not sure which one works.

i’ll find out! Thanks slick

 

[SrC]

Many companies now deleted their phone contacts. To save coin these days. Avoiding warranty claims. The way of the world.
Making it harder for the consumer.

HH is not in control of their Outsourcing Factories.
You can't even find where these factories are. It's a secret.
I bet 99% of HH doesn't even have a clue.
Arrma, UK is ultimately responsible for factory QC issues. Last I heard. At least for initial new production runs.
JD knows this. ( Arrma founder/engineer)

Part of the China business culture to cut corners. Cheezy......unskilled slave labor and so forth. All CH produced goods. State controlled Greed.
They crap out goods with fancy Box art, and false claims. And their culture supports this. Even within their own society.

 

[JustAnOutcast]

i didnt know they would do that! how do you contact them typically? I have an esc i need to send it for cogging and outside of filling out their online form for repair I’m unsure how to go about it. they hide the phone number on the site, probably for a reason, but I’d like to talk to someone to get a better idea of what to do/what they actually need for a warranty repair. When your new rtrs have issues do you call them, or use the online form and wait however long they want to take to respond?

I’ve had good luck using the chat link on the Arrma site. Have contacted them three times so far and they have always responded quickly and resolved my issues.

 

[oregoncoastrc]

Many companies now deleted their phone contacts. To save coin these days. Avoiding warranty claims. The way of the world.
Making it harder for the consumer.

HH is not in control of their Outsourcing Factories.
You can't even find where these factories are. It's a secret.
I bet 99% of HH doesn't even have a clue.
Arrma, UK is ultimately responsible for factory QC issues. Last I heard. At least for initial new production runs.
JD knows this.

Part of the China business culture to cut corners.

Interesting. What’s the point of keeping them secret? Keeping us from showing up with pitchforks?

 

[slick2500]

Interesting. What’s the point of keeping them secret? Keeping us from showing up with pitchforks?

So we can't see how the sausage is made.

 

[oregoncoastrc]

So we can't see how the sausage is made.

But i wanna see the sausage

 

[SrC]

I beat it with a stick. I looked and can't find any trace of these factories. I know there is more than one. I even asked HH. They have no clue, or would not say.
Even China's GPS system is "purposely" flawed to be off by many miles. Sounds stupid. But it is by CCP's own design. Another topic that is very true.
A protectionist attitude.
I only know that when Hobbico owned Arrma and Axial before bankruptcy, that it was DragonStar RC company making these RC cars.
Not a trace of this company exists today. But this company actually designed and created these RC's. Hobbico just bought rights and branded them as Arrma (also disfunct Team Durango) and Axial. What we know today.

 

[Tex Koder]

Interesting. What’s the point of keeping them secret? Keeping us from showing up with pitchforks?

It's a National Security Secret for the Communist Party to not let foreigners see where Cjhina is operating their "factories"..
Because They outsource too.
Can't claim "Made in China" when folks start to see it's from other countries.

So we can't see how the sausage is made.

No.
it's because there's just ONE Customer Care personnel who's answering calls.. So, that one phone gets all jammed up IF they post the number.