This is my tractor truck, approximately scale 1:10, inspired by an Iveco Stralis.
It 's almost completely IR-controlled, four-wheel drive with an XL engine almost directly connected to each wheel (only a couple of gears for each motor).
It has steering wheels, driven by a servo motor, with working steering wheel.
The first axle has independent suspension, the 2nd and 3rd are live axles with pneumatic self-leveling suspension.

It has a double pneumatic pump for compressed air, moved by 1 M motor. Another M Motors move 1 pneumatic valve, for lock the fifth wheel.
There are another 2 valves, activated manually, 1 for the cab tilting and 1 for give compressed air to the trailer.

A electric switch is used to turn on/of the front light, even this manually.

Dimensions:

Height: 51 (45) studs (without aerials)
Width: 37 (31) studs (without mirrors)
Length: 71 studs
Weight: 5.9 Kg

PF Elements:

4 XL Motors for Drive
1 Servo Motor for Steering
1 M Motor for Pneumatic Pump
1 M Motor for locking the fifth wheel
2 IR Receivers for Drive
1 IR Receiver for Steering and locking the fifth wheel
2 PF Lights for Front Light
1 PF Switch for Front Light
1 Extension Cable
3 AAA Battery Packs

Pneumatic elements:

2 S Pnematic Pumps
4 M Pneumatic Cylinders for rear suspensions
2 M Pneumatic Cylinders for Cab Tilting
1 S Pneumatic Cylinder for auto off the compressor
1 S Pneumatic Cylinder for locking the fifth wheel
2 Pneumatic Valves for rear suspensions
1 Pneumatic Valve for cab tilting
1 Pneumatic Valve for locking the fifth wheel
1 Pneumatic Valve for give compressed air to the trailer

Instructions will be available soon.