48 2.0 Whining noise on first run

[Krackar]

Gave my 2.0 its maiden run today at a local school oval. It had a weird whining noise when at near to and at full acceleration. It seemed to lessen the longer I ran it. Other than the noise the buggy was perfect.

There was no binding in any of the drive train, pinion mesh was perfect and didn't change. Full stock set up. 1900kv motor, XR8 SCT with 16t pinion.

I haven't had a chance to look deeper into it yet. Could it just be new drive train wearing in? Any other places to star looking? Everything is still free with no binding at all.

 

[TBuggy]

You said the mesh is perfect...unless there is something loose and or literally flapping (like wires, or possibly even debris) my thought is that your pinion to spur gear mesh possibly too tight?

Its really hard to say what your problem is without pictures or even better a video.

 

[Billl DeLong]

... my thought is that your pinion to spur gear mesh possibly too tight?

+1

How did you set the mesh?
Did you use a piece of notebook paper to fit the gap?

 

[Skynet5]

+1

How did you set the mesh?
Did you use a piece of notebook paper to fit the gap?

This is what I did.

Slither of paper, against spur. Push pinion up against it. Lock in place, and pull paper out.

Paper pulled out should require a gentle tug with no chance of ripping.

You should be able to rock the spur gear a little without the pinion moving. You can hear the teeth knock side to side.


At least that's what I do.

 

[Krackar]

I set the mesh with the paper trick. I set it at the tightest point on the Spur gear.

I'll go over it today and check everything then run another pack in it. I'll try and get some video if it persists.

I'll report back later. Thanks for the responses!

 

[Krackar]

I think I may have found it. Was cleaning and removed one of the rear wheels. There was a small stick stuck inside wearing onto the rim. Which would explain the sound lessening as I continued to drive. I'll verify later when undoubtedly one of my sons wants to use the rc cars lol

 

[Krackar]

(like wires, or possibly even debris)

Looks like debris lol

 

[Krackar]

An update for this. The noise persisted after thinking it was debris.

I checked all the diffs, all the wheel bearings, cleaned all the cvd's. The noise persisted. It would be loud when first running the car then slowly lessen as it warmed up.

I ended up ordering some new bearings for the motor. I replaced the larger bearing on the shaft end and had the wrong size for the other end. The correct size is now on the way.

I've had a chance to run it once after replacing the bearing and no noise. The bearing I replaced was smooth as silk but must have had an imperfection somewhere. Just because it was new doesn't make it good!

Glad I found it anyway. Could have got a lot worse and maybe cost me a motor. Thanks for some pointers anyway.

 

[SHANKxTANK]

I had a hyper7 a long time ago. When the ring and pinions would get dry they had a horrible whining noise. Make sure the ring and pinion has a good coat of grease on them.