The Samix Traxxas TRX-4 Aluminum Servo Horn is a double clamp lock style horn developed specifically for TRX-4 trucks. Precision machined to exacting specifications, this horn matches the TRX-4 geometry perfectly and is a great upgrade. The arm features a unique shape and dual clamp design that will keep the horn locked securely to the servo output. Package includes one 25 tooth servo horn and clamp lock hardware.
- Machined from high quality aluminum
- Clamping head for secure mounting in high stress applications
- Clamp hardware included
- Available in multiple color options with laser etched samix logo
- Available in 23T and 25T servo applications
This product was added to our catalog on December 19, 2017
This horn is flat and too thick, while original horn is not(it has steps). It moves steering link rod end down 3mm and it changes suspension geometry. For wheels to be straight, horn must be turn to the side and steering angle on that side is limited a bit then. Also screw that is holding steering link rod end to horn itself is binding with drag link under full compression. Horn itself touches panhard rod slightly under full compression.
My friend shaved it on CNC for me. Original horn is 6mm thick. I made it 5mm thick where it is attached to servo shaft to clear a panhard rod. And 3mm thick where rod end is to clear drag link and move rod end into position where it is meant to be. I suppose you can do the modification yourself even with dremel if you want. I have a picture of modified horn : https://www.rcportal.sk/public/upload/1527615587-4643.jpg
But other than that, as I said you can live with this horn as it is. You truck axle will not be under full compression while driving very often and most people will not notice slightly limited steering angle on one side at all. But it is shame they do not address this issues under development, especially when it was design for trx-4 exclusively.