Senton Need help troubleshooting noise

[rflx]

Hey forum ?

My Senton 3s is producing some unsettling sounds and i'm having trouble finding out what the issue is. Before it started, i had opened up the motor (everything looked fine), changed to a 15t pinion, changed the diff syrup (100k/30k), put on 17mm hex adapters and buggy tires and tried adjusting the slipper clutch.

Now the Senton makes a very loud grating sound under acceleration, much louder than the usual noise. It does not happen when im holding the car up and all wheels are spinning freely. When i'm holding the rear tires in place and pull the throttle, the front tires spin and i can hear the grating. When i'm holding the front tires, the rear tires spin but there is no (or very little) grating.
I have taken another look at the pinion and spur gear - the teeth are fine and the mesh looks alright. The differentials and input gears looked fine when i changed the syrup.
I tried loosening and fastening the slipper clutch, but it did not seem to make a difference.

Any help is appreciated!

 

[slick2500]

Hey forum ?

My Senton 3s is producing some unsettling sounds and i'm having trouble finding out what the issue is. Before it started, i had opened up the motor (everything looked fine), changed to a 15t pinion, changed the diff syrup (100k/30k), put on 17mm hex adapters and buggy tires and tried adjusting the slipper clutch.

Now the Senton makes a very loud grating sound under acceleration, much louder than the usual noise. It does not happen when im holding the car up and all wheels are spinning freely. When i'm holding the rear tires in place and pull the throttle, the front tires spin and i can hear the grating. When i'm holding the front tires, the rear tires spin but there is no (or very little) grating.
I have taken another look at the pinion and spur gear - the teeth are fine and the mesh looks alright. The differentials and input gears looked fine when i changed the syrup.
I tried loosening and fastening the slipper clutch, but it did not seem to make a difference.

Any help is appreciated!

Best way to diagnose sounds is a video. Describing the sound sometimes can help but often times is not enough.

 

[jondilly1974]

From that description it sounds like a diff input or main gear.

 

[rflx]

Best way to diagnose sounds is a video. Describing the sound sometimes can help but often times is not enough.

I tried recording a video before posting here, but it does not sound at all like the real thing. I could try to record using my microphone and upload an audio file.

From that description it sounds like a diff input or main gear.

Alright, guess i will have another look at the diff input gears, maybe i missed something.
What is the "main gear"? The one in the middle of the slipper clutch?

 

[slick2500]

I tried recording a video before posting here, but it does not sound at all like the real thing. I could try to record using my microphone and upload an audio file.

Alright, guess i will have another look at the diff input gears, maybe i missed something.
What is the "main gear"? The one in the middle of the slipper clutch?

He is talking about the gears for the diff in the front and rear, the main gear is the large crown or ring gear that is attached to the diff cup, the input or pinion gear is the small one that attaches to the center driveshaft. The one that attaches to the slipper is called a spur gear. The gear on the motor shaft is also referred to as a pinion gear.

 

[rflx]

Thank you guys. I'm confused because everything was fine before I made all the changes. I didn't get to taking out the diffs today. Will report back after checking tomorrow.

 

[slick2500]

You may have missed something when putting the front diff back together as you mentioned the sound seems to be coming from that area. At this point it really is just a guessing game on our part.

 

[rflx]

Alright guys, it took me a looong time to get back to the Senton. I followed your suggestions and indeed, the main gear of the rear diff case is partly stripped. About one fifth of the teeth are noticeably shorter, so I assume that's my issue. It was not obvious from a cursory glance, so I must have missed it during assembly.
I can't find a single shop in Germany that has the part in stock, but the UK folks have me covered

Thank your for you help in figuring this out.

 

[rflx]

Umph, i cannot find anybody on this continent willing to sell me the differential case that i need to replace (AR310872). All german shops are out of stock, Modelsport UK has stopped international delivery.
I'm thankful for any pointers! Not very keen on ordering from the US because it's expensive and will probably take a loooong time.

Hope your rigs are holding!

 

[ph47mf]

This is my local one, see if it's any good...

https://wheelspinmodels.co.uk/i/307774/

 

[rflx]

This is my local one, see if it's any good...

https://wheelspinmodels.co.uk/i/307774/

Thank you mate! They even had all the other parts i need right now, so i just ordered everything from them.