Overview
The ARB Old Man Emu Nitrocharger Sport Rear Strut, part number 90048, is a rear coilover strut for the Ford Bronco 4-door. It fits the 2021–2022 Bronco in the Badlands, Base, Big Bend, Black Diamond, First Edition, Outer Banks and Wildtrak trims. It is tuned for use with Old Man Emu coil springs 3204, 3205 and 3206.
The rear strut is built to maximize the travel of the vehicle’s geometry. It uses Nitrocharger Sport valving, matched to spring selection and load.
The polyurethane bushing is designed to extend shock life, and the impact-resistant dirt shield guards against off-road debris. The induction-hardened chrome piston rod suits 4×4 touring use. A triple-lip oil seal helps keep contaminants out, and the Teflon-infused slip ring and bronze bushing support steady damping.
The nitrogen gas charge widens the usable temperature range and improves oil flow. An open length of 27 inches and a closed length of 16.73 inches should be compared with your suspension travel before fitting.
Key features
- Tuned for Old Man Emu coil springs 3204, 3205 and 3206
- Polyurethane bushing for longer shock life
- Impact-resistant dirt shield against off-road debris
- Induction-hardened chrome piston rod
- Triple-lip oil seal and Teflon-infused slip ring
- Nitrogen gas charge, multi-deflective disc valving
Choosing the right setup
Rear coilover struts work as a pair with the springs around them, so the strut and spring should be chosen together. A strut tuned for a specific spring rate keeps the damping in step with the load the spring carries. When the spring changes, the valving can stop matching the ride, which is why staying within the matched spring family keeps the setup predictable on the trail and on pavement.
Off-road, a strut that handles compression and rebound smoothly helps the rear axle follow uneven ground without the body feeling loose. Wheel travel, payload and tyre size all change how hard the strut works, so a vehicle carrying extra gear or running larger tyres may reach the stroke limits sooner. Check the strut’s open and closed lengths against the travel you actually use before committing to a setup.
- Match the strut to the spring family it is tuned for
- Check mounting eyelets and bushings for play after the first trail runs
- Inspect the dirt shield for dents that could rub the body
- Look for oil residue on the piston rod, which can signal seal wear
Specifications
| Brand | ARB 4×4 Accessories |
|---|---|
| Part number | 90048 |
| Shock series | Nitrocharger Sport |
| Location | Rear |
| Shock type | Coilover |
| Top mount | OEM |
| Bottom mount | Eyelet |
| Body diameter | 51 mm |
| Open length | 27 in. |
| Closed length | 16.73 in. |
| Charge | Gas charged |
Vehicle fitment
It fits the 2021–2022 Ford Bronco in the Badlands, Base, Big Bend, Black Diamond, First Edition, Outer Banks and Wildtrak trims. Other Ford models and Bronco years outside 2021–2022 are not covered. Confirm your vehicle’s year, model and trim before ordering.
Ford models other than the Bronco, and Bronco years outside 2021–2022, are not covered. Confirm your vehicle’s year, model and trim before ordering.
Installation notes
Use this strut with the Old Man Emu coil springs it is tuned for. The strut is built for 4×4 touring, and its valving is matched to the spring choice.
