What is a Normal or Bad Sound of a RC Transmission?

parcou

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Hey Fam need vet advice!

I am not having any issues that I am aware of...
As I newbie in the hobby, I have not really seen anything or found anything to the current date on transmission sounds that's good/bad...

Example #1:
Losi Tenacity DB Pro

It sounds good under power no binding or gears making noise I can hear. I did have a post where you all showed me that Losi shipped me bad crown or planetary gears for rear diff. Replaced those and it no grinding sound as it moves. The last runs were fine. On the Losi if I am on dirt or low loose grass\dirt, and I power slide it very hard at full speed to a 180, sometimes I hear a sound like that when you are rolling the RC when it is off. I do hear a gear noise for a brief moment until out that very hard turn. Or, if I land wrong and one of the tires is slammed or pinned in a position before it is free, I hear that same sound of a gear noise. Makes me think of the sound of a slipper clutch, but the Losi has 3 diffs. Is this a sound that's protecting the RCs gears or something else? I see not teeth missing on the motor pinion or spur but have not looked at the center diff internally in a few runs.

Example #2:
BR or Granite BLX

This one does have the slipper clutch and I've had tons of bad landings when it comes down on a wheel or one was not in the right direction yet. I assume that quick gear winding\grinding I hear is coming from the slipper clutch on the BR, right?

Some in Example #1 what protects a 4x4 basher gears like the Losi when a wheel or something is hung up...is there slip protection?

Just curious to what is normal sound and bad...

@razorrc
 

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I'm not razorrc, but have a Granite. The Granite makes a whining noise, even at slow speed. I assume it doesn't come from the drivechain (slipper) because mine makes that sound even when not hitting the throttle but just coasting around slow. I think its the ESC or motor, but it's not upsetting. If you watch vids of Granites on youtube they all make a whining noise.
A grinding sound is a warning.
 

parcou

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I'm not a veteran but what protects a 4x4 is the center diff this acts as a slipper clutch to a point. It will only protect the gears if it isn't locked with extremely heavy oil. Someone please correct me if I'm wrong.

I welcome any advice..... This is what I am after to learn if this is the center diff. On the Losi DB Pro, it has 10k in the center but it is an RC that does not need heavy oil.

Like to just know what is that sound when the wheels are under a force like when I slam that turn an it makes that noise.

I'm not razorrc, but have a Granite. The Granite makes a whining noise, even at slow speed. I assume it doesn't come from the drivechain (slipper) because mine makes that sound even when not hitting the throttle but just coasting around slow. I think its the ESC or motor, but it's not upsetting. If you watch vids of Granites on youtube they all make a whining noise.
A grinding sound is a warning.

Thx for the post all good! I do hear that sound when it is moving I agree that is normal. But if I send the BR wrong and it lands in a crazy way....it is not that sound but I feel it is the slipper clutch trying to take some of that power away until the rig gets back right\level on the ground.

I'm just trying to find the RC science or video or info that explains for 3 diff, and that for slipper clutch how it protects them and maybe explain some of those sounds :)
 
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I welcome any advice..... This is what I am after to learn if this is the center diff. On the Losi DB Pro, it has 10k in the center but it is an RC that does not need heavy oil.

Like to just know what is that sound when the wheels are under a force like when I slam that turn an it makes that noise.



Thx for the post all good! I do hear that sound when it is moving I agree that is normal. But if I send the BR wrong and it lands in a crazy way....it is not that sound but I feel it is the slipper clutch trying to take some of that power away until the rig gets back right\level on the ground.

I'm just trying to find the RC science or video or info that explains for 3 diff, and that for slipper clutch how it protects them and maybe explain some of those sounds :)
Is it a clicking noise?
 

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I welcome any advice..... This is what I am after to learn if this is the center diff. On the Losi DB Pro, it has 10k in the center but it is an RC that does not need heavy oil.

Like to just know what is that sound when the wheels are under a force like when I slam that turn an it makes that noise.



Thx for the post all good! I do hear that sound when it is moving I agree that is normal. But if I send the BR wrong and it lands in a crazy way....it is not that sound but I feel it is the slipper clutch trying to take some of that power away until the rig gets back right\level on the ground.

I'm just trying to find the RC science or video or info that explains for 3 diff, and that for slipper clutch how it protects them and maybe explain some of those sounds :)
Slipper is in lieu of a center diff on 3s Arrma models at least. So no oil. I’ve not heard a car with a center diff but am figuring it’s different.
 

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slam that turn an it makes that noise.
Could it be something as simple as tires rubbing the body or similar? You said it happens when you slam that turn…if your steering is fully open, body flapping under speed wind bouncy whatever, it could flair out and make contact maybe? I had something similar on a rc car thet a pair of curved scissors took care of.
 

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Is it a clicking noise?

As for the Losi, it is not a clicking noise. It does not sound like bad gears which was the grinding gear sound when the crown gears were bad in my rear diff. This sound only happens when I put a load on the Losi if I turn hard in the grass that really grabs the tires in that 180deg turn. If I just the Losi and it lands on one wheel the wrong way...it's more like a sound of an old school revolver gun spinning. Just really driving and bashing does not happen rig sounds good.

Slipper is in lieu of a center diff on 3s Arrma models at least. So no oil. I’ve not heard a car with a center diff but am figuring it’s different.

No oil, no issue, or teeth missing. A lot of these 6S rigs have 3 diffs and the Losi has 3 diffs f/c/r so trying to see how that works to protect the gears/drivetrain with the sound I hear sometimes describes above. With the BR, I can tell when the slipper helps it has a noticeable sound that's different.
 

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As for the Losi, it is not a clicking noise. It does not sound like bad gears which was the grinding gear sound when the crown gears were bad in my rear diff. This sound only happens when I put a load on the Losi if I turn hard in the grass that really grabs the tires in that 180deg turn. If I just the Losi and it lands on one wheel the wrong way...it's more like a sound of an old school revolver gun spinning. Just really driving and bashing does not happen rig sounds good.



No oil, no issue, or teeth missing. A lot of these 6S rigs have 3 diffs and the Losi has 3 diffs f/c/r so trying to see how that works to protect the gears/drivetrain with the sound I hear sometimes describes above. With the BR, I can tell when the slipper helps it has a noticeable sound that's different.
That clicking sound you’re describing reminds me of when a cvd joint is going out on the front wheel drive car of an older car. Never messed with a Losi so I have no idea how those are set up.
 

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Could it be something as simple as tires rubbing the body or similar? You said it happens when you slam that turn…if your steering is fully open, body flapping under speed wind bouncy whatever, it could flair out and make contact maybe? I had something similar on a rc car thet a pair of curved scissors took care of.

Hi. None of those the Losi tires are open and I am dialed in to find those.... Yes, it happens when I seem to oppose the direction or a force on the tires or drivetrain. Same on the BR with a slipper clutch if I do something the wheels don't like it the slipper engages to protect the rig.

I think this is what is happening because on a clean jump or no bad landings, etc no sound I am referring to...if I land wrong like on one wheel and not all four it makes a sound I refer to like a revolver gun for a brief moment and back to bashing I go. I don't know if there is a form of a clutch in the center diff that has some form of protection...why I am asking.
 

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Yesterday I opened the center diff after opening the f/r a few days prior to maintenance.

All looks good planetary and spider gears have no marks on them. I have seen a few videos where some added more shims to lift the planetary some but by doing so the gear grind hard together it's not smooth at all...catchy. I choose not to do so just did not feel right comparing it to how my Arrma diffs fill.

This rig is running light oil on the 3S power but recommended by Horizon when I emailed them was 5/5/3 f/c/r. I run 7/10/5 but yesterday I made it 7/15/5.

Watched @razorrc video explaining diffs and a few others on open diffs. Like I said it runs fine just on those jumps if I land wrong or hard turn when the tire may catch or whipping it in a 180 (normally only in light\low grass where it digs in more) that is not all the time I get a sound from one of the diffs. Based on my limited knowledge and what I have seen, I make the assumption it is operating fine. Just with open diffs when it sends all that power to the least resistant wheel the full push of all that power spins it so hard I think it is a diffing out sound I am not familiar with. Nothing is broken but a unique sound when that power turns one side extremely hard or land hard on one of the wheels. Soon after it happens bash off sounding normal.

I'll keep watching and trying to learn. Thx all
 
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