Bully 2 - noisy rear axle

[Shmilcat]

Hi, need some advice from you experts.

I recently purchased a RC2WD Bully RTR. since then I replaced the servo and rearranged the electronics.
really happy with it other than two issues:

The first is that almost every run ends by some minor failure - either a broken rod end, a torn motor wire, etc. - this is believe will be ironed out, and may be attributed to my lack of experience in setting up the rig.

The second one I noticed once I installed a DIG. Initially I just thought that the crawler is noisy, and having no experience, believed it is meant to be this way. However once I operated the DIG, I noticed that only the rear axle is noisy, while the front is much more quiet. It is kind of a high pitched noise.

I tried recording this, not sure you can hear the difference:
In the video I first run the front, then the rear, and finally both

any ideas?

https://www.youtube.com/watch?v=tTM5lvjgUPI

[josh6575]

These axles use a very specific pinion gear. Are you using the ones made for them?
Also sounds like the mesh could be too tight.
If you are thrashing on it hard enough break rod ends and rip wires, then the rear motor could have been pushed in to make it tighter.

[cboggs]

You can try adjusting the pinion gear mesh and see if that quiets it down some.

[Shmilcat]

Originally Posted by josh6575

These axles use a very specific pinion gear. Are you using the ones made for them?
Also sounds like the mesh could be too tight.
If you are thrashing on it hard enough break rod ends and rip wires, then the rear motor could have been pushed in to make it tighter.

I'm using the axles as I received them from RC4WD - I assume they installed the correct pinion gear.

Also sounds like the mesh could be too tight.
If you are thrashing on it hard enough break rod ends and rip wires, then the rear motor could have been pushed in to make it tighter.

You can try adjusting the pinion gear mesh and see if that quiets it down some.

since I'm completely new to this - could you direct me to or elaborate on how to change the the mesh tightness and how to know the right amount?

I don't want to noob this forum, but I assume this is a specific model questions. so I appreciate the answers and efforts

[cboggs]

Easiest way is to slightly loosen the motor screws and gently move the motor whichever way makes it quieter.... move motor, apply throttle, move motor again and reapply throttle, and so on till you get it right. Just very small adjustments is all your needing to do, as in barely moving the motor.

[josh6575]

I like to set the pinion mesh by taking off the inspection cover and looking at the gears. Loosen both motor screws and lightly tighten the one that is stationary. The one that follows the arc needs to be loose so you can make adjustments with a bit of pressure. Push the mesh all the way together then back it off until you can turn the wheels and notice a slight gap between the teeth of the pinion and first trans. gear. The gap between the teeth should be about the thickness of a piece of paper. A little bit of grease will also go a long way in these axles. My first 2.2 crawler was the same model and there was not much grease in there. Just a thin coat to gears will do. Packing it in there is just unnecessary weight.

[Shmilcat]

Thanks for the advices.
will try to do this over the weekend

[Shmilcat]

Update:

during this morning runs, the front axle motor dislocated and essentially turned the bully into rear drive rig.

from a certain perspective - a combination of my two issues .

and this is after going over the crawler and re-tightening and loctite applying any bolt. the second time.

Well, I guess this weekend will be relocating the motors.

[Shmilcat]

Another update:

re-aligned the motors.
also added thread lock to the motor screws

the rear motor was too tight, the front - on its way to disengagement

now they both sound about the same - not so noisy

Thanks

[Basherman61]

I had the pinion gears on my Bully 2 come loose right away. I always clean the pinion gears and set screws with alchohol now too remove any grease or oils. Then apply blue loctite to set screw and tighten. Let it dry over night and I have never had them come loose again.