Kraton “Clack” when getting onto throttle

[MarkDfromtheSouth]

One thing I noticed is when holding the RC in the air, I can’t replicate the sound. It seems to need resistance, like from the ground, to be able to do it. Free wheeling will not make the noise.

I’m going to just have to tear it all down and closely examine everything. Thanks y’all for all the advice!!

 

[joshludden]

One thing I noticed is when holding the RC in the air, I can’t replicate the sound. It seems to need resistance, like from the ground, to be able to do it. Free wheeling will not make the noise.

I’m going to just have to tear it all down and closely examine everything. Thanks y’all for all the advice!!

How about your diff outdrive cups digging into the rear arms under heavy throttle, you see any gouges?

 

[KevinC]

Melted motor leads into the ESC can also cause issues like this. Have a look at those.

 

[MarkDfromtheSouth]

How about your diff outdrive cups digging into the rear arms under heavy throttle, you see any gouges?

I actually adjusted my droop recently as well, as a precaution (lol)

Melted motor leads into the ESC can also cause issues like this. Have a look at those.

I’ll take a look at those tomorrow, but I don’t recall noticing that. Thanks

 

[joshludden]

I actually adjusted my droop recently as well, as a precaution (lol)

I’ll take a look at those tomorrow, but I don’t recall noticing that. Thanks

Yeah, I would double check your droop to make sure you're shocks aren't bottoming out too far. There's a little cutout, but you'd see noticeable gouges in your a arms if they are digging too much.

 

[nathanlow]

make sure the diff cover is fully tightened down, and the screws are not loose when tightening.
Under load, the diff can move forward/backwards causing gap between input gear and diff ring gear.

 

[ross_jsy]

One thing I noticed is when holding the RC in the air, I can’t replicate the sound. It seems to need resistance, like from the ground, to be able to do it. Free wheeling will not make the noise.

Sounding more and more like a ring and pinion gear I'm afraid dude.

Generally when my stuff starts clicking I'll just send it till it won't drive. You will soon find out what is failing lol

But seriously, if you have shimmed the bearing on the ring gear so there is no slop, have a look at the pinion engagement with the ring gear.

First, you should assemble that pinion with a little preload on the bearings (i.e. hold the pinion with your thumb and the input cup with your forefinger and lightly squeeze whilst tightening the grub screw), then reassemble and check the mesh. If the pinion isn't engaging fully, disassemble and shim the pinion out.

I find when a diff starts clicking, it is on its way out regardless. But shimming it like that has gotten me a few more packs out of some fairly knackered diffs on several occasions

 

[Hector_Fisher]

I'm pretty sure the clack you're hearing is the driveshaft pins hitting the diff outdrives on each axle. As the diff outdrive cups and driveshaft pins gets worn over time from rubbing on each other, they develop slop between them. This is consistent with you saying the issues seems to have developed over time. When you move back and forward, the pins tap from one side of the drive cup to the other. When you accelerate, the pins move and then "clack" against the drive pin. When it's new, there very little slop between the drive cups and pins, so it's alot less pronounced. Its a common thing that's developed on most of my metal drive train RCs.

That's the first thing I would be checking for. What do your drive cups and driveshaft pins look like on the F/R diffs?

 

[Dan B.]

Generally when my stuff starts clicking I'll just send it till it won't drive. You will soon find out what is failing lol

Yes, I agree with that

First, you should assemble that pinion with a little preload on the bearings (i.e. hold the pinion with your thumb and the input cup with your forefinger and lightly squeeze whilst tightening the grub screw), then reassemble and check the mesh. If the pinion isn't engaging fully, disassemble and shim the pinion out.

That is exactly the method I use. When possible I use 8mm PTFE coated shims on the inputs on both bearing faces as well, this depends on tolerances.

 

[Moirae]

My kraton started doing this too. Thought I fixed it but nope! I think i'm going to replace the bulkhead with a metal one and hope it's cracked.

 

[Dan B.]

I think @Hector_Fisher nailed the culprit in post 28 above. I had the same thing with my NOTO, I just came home at lunch and looked at it and there is visible grooving where the center shaft pins engage the input cups.
And don’t get me wrong, I’m normally a big fan of some visible grooving but this just ain’t groovy, man.

 

[Senton_Prime]

I think @Hector_Fisher nailed the culprit in post 28 above. I had the same thing with my NOTO, I just came home at lunch and looked at it and there is visible grooving where the center shaft pins engage the input cups.
And don’t get me wrong, I’m normally a big fan of some visible grooving but this just ain’t groovy, man.

Let me see so I can check mine