Outcast High pitch "squeal" under full throttle.

[Sb09]

I recently acquired a second hand Outcast. First day I had it, I trashed a pinion. I replaced said pinion and the truck runs fine. But, I am getting a high pitch "squeal" noise under heavy throttle that wasn't there before the pinion replacement. Any ideas what is causing this?

 

[98jdmcivic]

How did you set the gear mesh? Might be too tight. Are you able to get the tires off the ground and pinpoint where the noise is coming from?

 

[Sb09]

I don't have any abnormal noise when spinning the tires by hand or rolling it across the ground. There isn't even any abnormal noise at moderate throttle. It's basically just at full throttle. I will back the gear mesh off a little bit and see if it helps. I've always used thin "receipt-like" paper to set my gear mesh. But, reading some past post here it seems like I should be using thicker paper on these Arrmas.

 

[Captain Dirt]

You should have a very slight play between the spur and pinion gears. If you rock them back and forth and they both move without any play then your mesh is too tight.

 

[slick2500]

Does it sound like this?

 

[olds97_lss]

Does it sound like this?

That has to be the motor bearing or something right? Sounds nasty!

 

[slick2500]

That has to be the motor bearing or something right? Sounds nasty!

Twas the motor bearing.

 

[Sb09]

That has to be the motor bearing or something right? Sounds nasty!

That sounds super nasty! I would say it's that same pitch of sound. But it only happens under heavy throttle and it is constant "squeal."
When just rolling by hand the truck sounds normal.

 

[olds97_lss]

Still could be your motor bearings then. Could try taking the motor off and spinning it up to speed outside the truck to see if it makes any weird sounds. I wouldn't let it run very long at WOT unloaded, taking the pinion off and leaving in the truck to do that would be the safest.

 

[LibertyMKiii]

My initial thoughts is bearings. It only occurs under full throttle and heavy loads because the torque applied on the bearing is heaviest in that scenario.

I'd start with motor and center diff bearings (assuming it is a 6s) then work your way out to the wheels.

 

[Sb09]

My initial thoughts is bearings. It only occurs under full throttle and heavy loads because the torque applied on the bearing is heaviest in that scenario.

I'd start with motor and center diff bearings (assuming it is a 6s) then work your way out to the wheels.

Good recommendation. I tried to loosen up the mesh a bit. Still same noise. Just messaged my LHS to see if he has a motor I can come by and pick-up. I'll try motor like you mentioned. I took apart the Center Diff last night and looked at everything. Seemed fine.

Just in case he doesn't have one, what is the recommended aftermarket replacement motor/ESC combo? I'm the type that likes to try new things when the stock parts break.

 

[LibertyMKiii]

Hobby wing max 6 seems to be a common favorite.
I like HW for their durability.

Castle MM2 is a great esc.

Just stick with a motor in the 1700-2200kv range for 6s use and should be fine.