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TAK-4® Independent Suspension

Pierce Fire Truck parked outside on a sunny day with a TAK-4® Independent Suspension System.

Safer. Smoother. Stops Sooner.



Proven, proprietary, severe-duty technology. Custom built for Pierce chassis. The TAK-4 Independent Suspension system maintains the feel of the road with outstanding steer-ability and a dramatically smoother ride over any surface. A tight steering system, torsion bar independent suspension and high-performance braking maximize control. It makes a 12-ton fire apparatus feel like an SUV.

TAK-4 was originally engineered and developed by Pierce’s parent company, Oshkosh Corporation, for military and aircraft rescue vehicles facing off-road duty. TAK-4 deals just as effectively with more mundane road events like pot holes, railroad tracks, speed bumps and crowned intersections. 

In 2001, Pierce changed the industry by introducing TAK-4 Independent Front Suspension (IFS), engineered specifically for Pierce vehicles. Pierce now offers TAK-4 Independent Rear Suspension (IRS) which applies the same military grade performance to the rear for supreme ride performance. For maximum mobility, Pierce also delivers TAK-4 T3™ system, which combines the advantages of TAK-4 IRS with a 100 percent mechanical rear steering system.



  TAK-4 Independent Front Suspension (IFS) TAK-4 Independent Rear Suspension (IRS) TAK-4 T3 IRS with Tight Turning Technology
Custom Chassis Enforcer™, Impel®, Velocity® Enforcer, ImpelVelocity  Enforcer, ImpelVelocity
Load Ratings 18,000 - 24,000 lb 24,000 - 52,000 lb 24,000 - 52,000 lb
Cramp Angle Up to 45° N/A Up to 9°
Wheel Travel

Up to 10"

Up to 14" Up to 14"
Dual Steering Gear Standard N/A Standard
Suspension Spring Type Torsion Bar Coil Coil 

Simplified Maintenance

The TAK-4 design not only maximizes a truck’s performance, it minimizes the wear and tear on your equipment and streamlines the maintenance process. There are no u-bolts on the front axle, no adjustments needed for the caster angle, and no need for lubricating the heavy-duty ball joints. Your rig spends less time in the shop and more time on the street.

Imperative Periodic Inspections
With a vast service network, Pierce provides you with trained certified technicians to perform routine maintenance and inspections that keep your vehicle running at its peak.

A certified technician servicing the TAK-4® Suspension System on a Pierce Fire Truck.


Pierce Fire Truck parked outside in a parking lot on a snowy day testing the TAK-4® Suspension System.

Testing the Most Brutal Road Conditions

Pierce partnered with the Transportation Research Center of East Liberty, OH to subject TAK-4 to the roadway works – chatter bumps, staggered bumps, high-crown intersections, ruts and potholes.

A 24,000-lb load was placed on the front axle to extreme-test the suspension, steering and braking systems. To gauge endurance, the vehicle then performed 17,700 actual test miles.

Based on our testing, the TAK-4 IFS was proven to outperform any other suspension system in existence in the most grueling conditions.