Senton Newb - Diff Issue? Horrible Grinding Noise

[GavinD]

Hi, my 8 year old son has a Senton 3S BLX. We only run it on 2S and it has a 13T pinion to slow him down and reduce damage. Not long ago it started making a horrible noise from the diff area. It turns out that the bearing for the Spur gear came apart in pieces, so I replaced them. But the noise remains. Is this a diff issue, slipper clutch, or something else? I pulled the motor and ran it while holding it and it didn't sound smooth and healthy but it didn't sound like this:

Arrma Senton Diff Noise Video

Any help is really appreciated.

Thank you
Gavin

 

[Velodromed]

Sounds like diff or spur… So your spur is okay? You checked it?

Hey man, pick up two diffs from jennys, throw one in the car to get it running (and know if you’re okay) and so your boy has his truck, then take apart and mess with the down one (with your boy, kids love that stuff). It’s what I do with many parts. Less stress lol. Jennys is a parts breaker. Affordable stock parts.

https://jennysrc.com/products/arrma...tial-front-rear-37t-granite-big-rock-ar102668

Sounds like diff or spur… So your spur is okay? You checked it?

Hey man, pick up two diffs from jennys, throw one in the car to get it running (and know if you’re okay) and so your boy has his truck, then take apart and mess with the down one (with your boy, kids love that stuff). It’s what I do with many parts. Less stress lol. Jennys is a parts breaker. Affordable stock parts.

https://jennysrc.com/products/arrma...tial-front-rear-37t-granite-big-rock-ar102668

When you pulled the motor did you push the chassis? Did it roll or crunch?

Sounds like diff or spur… So your spur is okay? You checked it?

Hey man, pick up two diffs from jennys, throw one in the car to get it running (and know if you’re okay) and so your boy has his truck, then take apart and mess with the down one (with your boy, kids love that stuff). It’s what I do with many parts. Less stress lol. Jennys is a parts breaker. Affordable stock parts.

https://jennysrc.com/products/arrma...tial-front-rear-37t-granite-big-rock-ar102668

When you pulled the motor did you push the chassis? Did it roll or crunch?

Pull motor, push chassis see if makes noise. Each wheel set will be isolated now so mess with each, feeling for any grinding. Honestly I’m not sure what else to do aside from that. If it was mine I’d take it apart…chase the problem till I found it. I’m sure others will chime in with more knowledge.

 

[jondilly1974]

Hi, my 8 year old son has a Senton 3S BLX. We only run it on 2S and it has a 13T pinion to slow him down and reduce damage. Not long ago it started making a horrible noise from the diff area. It turns out that the bearing for the Spur gear came apart in pieces, so I replaced them. But the noise remains. Is this a diff issue, slipper clutch, or something else? I pulled the motor and ran it while holding it and it didn't sound smooth and healthy but it didn't sound like this:

Arrma Senton Diff Noise Video

Any help is really appreciated.

Thank you
Gavin

To me that’s a seized motor bearing, but something is for sure binding.

 

[GavinD]

Thanks for the quick replies. I did not push the chassis without the motor, that is easy to do and a good suggestion. I will check it and report back. I ordered a diff just in case from JRC. I wasn't able to source an input gear anywhere

Thanks
Gavin

 

[Kla912000]

Here, Jenny's has input gears in stock for a Granite which are the exact same thing as your Senton. You get 2 input gears with 2 bearings on each gear for only $16. There are only 2 sets left. Hurry and get them before they are gone.

https://jennysrc.com/products/arrma...-bevel-gears-hd-13t-bearings-senton-ara4302v3

 

[Velodromed]

Here, Jenny's has input gears in stock for a Granite which are the exact same thing as your Senton. You get 2 input gears with 2 bearings on each gear for only $16. There are only 2 sets left. Hurry and get them before they are gone.

https://jennysrc.com/products/arrma...-bevel-gears-hd-13t-bearings-senton-ara4302v3

I forgot about the input gear lol. Those are good to have a couple spares.

 

[thrak76]

I forgot about the input gear lol. Those are good to have a couple spares.

Especially since it seems near impossible to get second bearing off the shaft!

 

[Velodromed]

Especially since it seems near impossible to get second bearing off the shaft!

I got a cute little gear puller for stuff like that. It even works half the time. Then there’s heat and freezing also.

 

[GavinD]

Sold out

 

[Velodromed]

Sold out

Hit the ‘notify me when available’ button. They won’t be out for long. When you get the email though, jump on it.

I have an extra set of input gears, two extra differentials, extra set arms, hub carriers…all from jennys lol. I didn’t have an extra spur gear and regret it because it went out on my vorteks. Now I’m waiting.

 

[GavinD]

Well, we figured out the issue. Either the bearing or the pinion left metal shavings that imbedded into the spur gear. Those shavings caused the gears to bind severely. Once I dug out the tiny fragments it ran fine. The pinion and spur gear do show wear and I will replace them when I can. I am learning what spares to keep around and a spur and pinion are on that list. Thanks for all of your help.

 

[Velodromed]

Well, we figured out the issue. Either the bearing or the pinion left metal shavings that imbedded into the spur gear. Those shavings caused the gears to bind severely. Once I dug out the tiny fragments it ran fine. The pinion and spur gear do show wear and I will replace them when I can. I am learning what spares to keep around and a spur and pinion are on that list. Thanks for all of your help.

Go ahead and cut the slot or drill a quarter inch hole underneath the spur. I held off doing that for a long time and did a lot of experimentation before I finally went ahead and drilled the hole. It does work to keep crud out of the gears Whether it comes from outside the car or inside.