---
title: TAK-4® Independent Rear Suspension System | Pierce Mfg
description: TAK-4 Independent Rear Suspension reduces road input on the vehicle, equipment and occupants while providing greater ride comfort and better traction.
---

# TAK-4® Independent Rear Suspension

![A Pierce Ascendant 100 Aerial Tower with TAK4 T3 Rear Suspension.](https://www.piercemfg.com/hubfs/TAK-4/TAK-4%20T3%20Aluminum%20Wheels/A-Pierce-Ascendant-100-Aerial-Tower-with-TAK4-T3-Rear-Suspension_WEB.jpg)

## Proven technology, front to back.

**[TAK-4 INDEPENDENT SUSPENSION BROCHURE](https://www.piercemfg.com/pierce/literature/tak-4-independent-suspension-brochure?hsLang=en-us)**

## IRS

### TAK-4 Independent Rear Suspension

Improved ride. Less maintenance. TAK-4 IRS operates in a similar capacity to TAK-4 IFS, only IRS has the ability to drive or provide power to the wheels. Though there are upper and lower control arms and springs, TAK-4 IRS utilizes coil springs instead of torsion springs. IRS has been proven on Oshkosh Defense vehicles since 1996 and modified for integration into Pierce custom fire apparatus. TAK-4 IRS adds 1,000 lb per axle to the weight of the apparatus.

**Benefits**  
• Improved ride with reduced road input.  
• Increased stability & comfort.  
• Less wear & tear on equipment.  
• Better traction.  
• Ability to add TAK-4 T3™ to further improve control & mobility.

![A close up of the rear tires turning on a Pierce Ascendant 100 Aerial Tower with Tak4 T3 Rear Suspension.](https://www.piercemfg.com/hs-fs/hubfs/TAK-4/TAK-4%20T3%20Aluminum%20Wheels/A-close-up-of-the-rear-tires-turning-on-a-Pierce-Ascendant-100-Aerial-Tower-with-Tak4-T3-Rear-Suspension._WEB.jpg?width=600&height=400&name=A-close-up-of-the-rear-tires-turning-on-a-Pierce-Ascendant-100-Aerial-Tower-with-Tak4-T3-Rear-Suspension._WEB.jpg)

 

## IRS Components

![TAK-4® IRS Components for a Pierce Fire Truck with an Independent Rear Suspension System. ](https://www.piercemfg.com/hs-fs/hubfs/TAK-4/TAK-4%20T3%20Aluminum%20Wheels/TAK-4%20Rear.png?width=600&height=337&name=TAK-4%20Rear.png)

 

**Steering**  
TAK-4 IRS is equipped with steering toe links that provide toe adjustments and maintain wheel control throughout the entire range of wheel travel.

**Control Arm**  
Cast steel alloy and ductile iron upper and lower control arms have integrated spring tower mounts.

**Springs**  
Heavy-duty coil springs provide maximum travel over a variety of road conditions.

## T3

### TAK-4 T3 IRS with Tight Turning Technology

**100 percent mechanical rear steering. Maximized mobility.**  
TAK-4 T3 combines the advantages of TAK-4 IRS with a 100 percent mechanical rear steering system. Just like TAK-4 IFS, the steering system is a mechanical-over-hydraulic system – free of electronics – with two steering gears that provide power to the steering linkage. TAK-4 T3 is available for steering on one or two axles on tandems. 

Reduce wide swing turns with a tighter turning radius. Maneuver effortlessly – turn the wheel and you get response. Minimize tire scrub for improved tire life. TAK-4 T3 is available on 24,000 - 26,000 lb single axle and 36,000 - 52,000 lb tandem axle configurations that are equipped with TAK-4 IRS. 

**Benefits**  
• Improved turning radius & turning diameter.  
• Increased tire life with reduced tire scrub.  
• Lane-to-lane turning.  
• Improved maneuverability & safety.  
• Pierce single-source manufacturing.

![The rear officer's side of a Pierce Ascendant 100 Aerial Tower with Tak4 T3 Rear Suspension.](https://www.piercemfg.com/hs-fs/hubfs/TAK-4/TAK-4%20T3%20Aluminum%20Wheels/The-rear-officers-side-of-a-Pierce-Ascendant-100-Aerial-Tower-with-Tak4-T3-Rear-Suspension._WEB.jpg?width=600&height=400&name=The-rear-officers-side-of-a-Pierce-Ascendant-100-Aerial-Tower-with-Tak4-T3-Rear-Suspension._WEB.jpg)

![Pierce Fire Truck driving in a parking lot in circles with a TAK-4® Independent Rear Suspension System. ](https://www.piercemfg.com/hs-fs/hubfs/TAK-4/Pierce_TAK4_Independent-Rear-Suspension-Turning-Radius.png?width=600&height=400&name=Pierce_TAK4_Independent-Rear-Suspension-Turning-Radius.png "Pierce_TAK4_Independent-Rear-Suspension-Turning-Radius.png")

## T3 Components

![TAK-4 T3](https://www.piercemfg.com/hs-fs/hubfs/TAK-4/TAK-4%20T3%20Aluminum%20Wheels/TAK-4%20T3.png?width=600&height=338&name=TAK-4%20T3.png)

 

**Steering**  
Mechanical-over-hydraulic steering system with two steering gears that provide power to the steering linkages.

**Control Arm**  
Cast steel alloy and ductile iron upper and lower control arms have integrated spring tower mounts. 

**Springs**  
Heavy-duty coil springs provide maximum travel over a variety of road conditions.

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