Do I need a new reciever?

[axial 4x4 crawler]

Hello, I am sort of new to the forums.
I have an axial wraith, and the other day I was out drive it and all of a sudden it starts turning its wheels and reacting while I am not even touching the throttle, I stand about 20-25 feet away from the wraith and then it looses connection with the transmitter. I don't know if this has to do with to much voltage for the servo or what.
Here is my upgraded electronics I am running:
- TEKIN RS ESC w/ a redline 13.5 t brushless (3500 KV)
- HITEC HS-7985 TH "mega torque" (560 OZ on 6.0 volts & 611 OZ W/7.4)
- Venom 30c 2s 5000mah LIPO battery
- Stock Reciever w/ stock transmitter
Do I need to use a BEC with this setup?
Thank you, if anyone could help I would appreciate it.

[Charlie-III]

Since the normal rule is, "Over ~200inoz of output torque, you NEED an external BEC"...yes, it can help you out.

Did you check the battery voltage? It may have been rather low which can also cause issues.

What about the batteries in the TX??

[offroadace]

Yes, you need a BEC.

I don't think I will ever run anything without an external BEC anymore. Less I have to think/worry about and it is an easy fix even if you remain at stock settings.

[axial 4x4 crawler]

Well the battery voltage is 7.4 volts and I am sure that it was charge all the way up. I found the castle creations 10 amp BEC, would this be ok for this set-up? And if I attach a BEC will that fix the loss of connection with the receiver and transmitter? I checked the TX batteries and they are fine.
Thank you for your help.