Big Rock What is this noise?

[matflat]

Dear Arrma Forum, we went out yesterday for a bit of a blast. The terrain was grass and then there was a small dirt track. No crashes, no daft stuff. On the short walk back to the car, the big rock made the noise you hear in the video. We didn’t drive it any further. This morning we stripped the car down, cleaned all dust, little stones out etc, opened the spur and pinion casing, cleaned it out. Put it all back together and went out for a run. The car makes the noise when the rc is at 75%. It doesn’t make it 50%. The car runs fine when off the ground at all speeds and in reverse. The steering doesn’t make any odd noises. I’m the video I am accelerating straight. Think it’s a bearing or perhaps there’s some small stone or something. Going to strip the wheels back this afternoon but was hoping that you might be able to pinpoint what this noise is and where it comes from. I cannot tell you if it is on the left, right, front or rear. Hope you can guide me right. Many thanks, mat.

 

[nomis38]

Do those have a slipper clutch maybe it needs tightened, thats what it sounds like but i don't know that truck very well. If its a 3s not a 6s most likely this is what it is. A clutch on the spur gear that needs tightened.

 

[Warby]

Video too short to really identify the sound.

 

[bukshypro]

That looks like your slipper clutch* screaming. Got loose or its just simply used up and in need for replacement. iirc ppl said the clutch pads/plates would need go be replaced about every 15-20packs.

Try tightening it carefully and if it gets loose again, time to replace the pads


*I said spur gear first somehow

 

[nomis38]

I see in the Sig its a 4x4 which is a 3s model. Def is the slipper clutch. Easy fix and its free. The reason for a slipper is because its all plastic drivetrain, if it didnt slip at least a little youd shred driveshafts constantly. 6s model's don't need a slipper and have all solid direct driveline because its all beefy steel gears and shafts.

 

[matflat]

Do those have a slipper clutch maybe it needs tightened, thats what it sounds like but i don't know that truck very well. If its a 3s not a 6s most likely this is what it is. A clutch on the spur gear that needs tightened.

Thanks @nomis38 - I’ll go and have a look and get back to you. Didn’t think about that when we’re checked the housing.

That looks like your slipper clutch* screaming. Got loose or its just simply used up and in need for replacement. iirc ppl said the clutch pads/plates would need go be replaced about every 15-20packs.

Try tightening it carefully and if it gets loose again, time to replace the pads


*I said spur gear first somehow

Thanks @bukshypro - going to check that a little later

 

[Hector_Fisher]

There sounds like two noises there. In addition to the slipper being loose, that honestly sounds like a motor bearing on its way out. Had my HPI Bullet and Traxxas summit make the exact same noise when the bearings (or bushings in the trx) were on their way out.

 

[matflat]

There sounds like two noises there. In addition to the slipper being loose, that honestly sounds like a motor bearing on its way out. Had my HPI Bullet and Traxxas summit make the exact same noise when the bearings (or bushings in the trx) were on their way out.

Hi @Hector_Fisher - many thanks for this. Can you perhaps tell me the part number for this so I can go look? I just stripped the pinion housing down and there is nothing wrong sleuth the slipper clutch, the pads , or anything wrong with the spur and pinion. Cheers, mat.

 

[Hector_Fisher]

Hi @Hector_Fisher - many thanks for this. Can you perhaps tell me the part number for this so I can go look? I just stripped the pinion housing down and there is nothing wrong sleuth the slipper clutch, the pads , or anything wrong with the spur and pinion. Cheers, mat.

No part number. It's the motors internal bearing, which comes with the motor. But can be replaced. (You can also warranty the motor for a bad bearing if you bought your truck from a horizon hobby authorized seller).

For bearings, you can use jimsbearings.com or similar site to tell you what size bearings you need for the motor if you're going to replace them. I would try and sort out the slipper as everyone described above first and see if that addresses the issue. Mostly because then you'll know for sure whether it was the slipper or not. Then in the future if you have the same noise again, you wouldn't be wondering again whether or not it's your slipper or motor bearing.

Also why I would try the slipper first is because it's much easier (low hanging fruit, if you will). Replacing motor bearings is more of an involved process.

 

[matflat]

No part number. It's the motors internal bearing, which comes with the motor. But can be replaced. (You can also warranty the motor for a bad bearing if you bought your truck from a horizon hobby authorized seller).

For bearings, you can use jimsbearings.com or similar site to tell you what size bearings you need for the motor if you're going to replace them. I would try and sort out the slipper as everyone described above first and see if that addresses the issue. Mostly because then you'll know for sure whether it was the slipper or not. Then in the future if you have the same noise again, you wouldn't be wondering again whether or not it's your slipper or motor bearing.

Also why I would try the slipper first is because it's much easier (low hanging fruit, if you will). Replacing motor bearings is more of an involved process.

Hi @Hector_Fisher thanks again for the reply. I took everything out again and ran the spur and pinion with the back cover off and out of the chassis. I can spin it flat out forward and reverse all the way to 100%. The place I bought it from won’t do jack even though it’s a month or so old so I am left to get the parts and replace unfortunately. I might just drop the motor from my Typhon in it and check if it does the same. Will report back. Thanks for the guidance.

 

[Hector_Fisher]

Remove the power module cover then take out the slipper assembly and spin the motor (using battey/controller). It shouldn't make any weird noises and should spin for at least a second or so after you let off the trigger. If that's good, search YouTube for some tutorials for how to tighten the slipper when assembling everything. I think Razor RC has a good one.

If your shop you bought from won't deal with warranty, just contact horizon hobby directly. They're usually pretty good with that stuff and getting you taken care of.

https://www.horizonhobby.com/product-support-landing.html
I believe the email on that page is:
[email protected]

 

[Velodromed]

That is one interesting sound. Haven’t heard that coming from any of my 3S cars. It doesn’t make the sound in the initial wind up and then the sound lets loose after a second or so it’s definitely a high-speed, vibrating noise. Hector could be right about the motor bearing. However, when you’re messing with the spur, check the spur bearings very closely. I would even swap them out with new bearings and then test run it. Very curious to find out what that sound is.
Do you run your car in the wet at all?

 

[nomis38]

Lord lolol, It's the slipper and that's it. Just tighten it and see, its free and easy... Don't buy any parts!!

 

[SrC]

^^^
+1
The video is not defining the noise well...
But the fact that it doesn't happen at 50% throttle power means you should focus on the slipper clutch first. And there is learning curve with it. Patience.
Look for YT videos in regards and search AF for threads in regards. This is common with 4x4 line rigs.

@razorrc has a great video in regards. Check his threads and on YT.

 

[matflat]

@SrC @nomis38 @Velodromed @Hector_Fisher @bukshypro @Warby Huge thanks to all of you for helping to troubleshoot this issue. Fortunately it wasn't the motor, and unfortunately nor was it the sluipper clutch (as I had a spare ). Turns out it was one of the two bearings on the pinion gear. I pulled out a working set from the Typhgon and put them on the Big Rock and all was well. Have ordered a couple of pairs extra to get us through the Xmas holiday as there will be plenty of blasting. You guys are awesome, so helpful in guiding me to pinpoint the issue and work out what is happening. Really appreciate the help. Now to sit and wait for the spare parts to arive

 

[Velodromed]

Turns out it was one of the two bearings on the pinion gear.

You mean on the spur? Pinion doesn’t have bearings…

 

[matflat]

You mean on the spur? Pinion doesn’t have bearings…

Did it again. Yes the Spur.

 

[Velodromed]

Did it again. Yes the Spur.

No worries, do that all the time myself. Yup, that’s what I thought the sound was. Glad you got it figured out and now you know for the next time