Trailer Slider Suspension Axle System

Featuring Haldex
Calipers and Actuators

Available on the SAF ULX40 trailer suspension, SAF-HOLLAND has developed the P89™ air disc brake system to meet the unique requirements of the North American trailer market.

SAF -HOLLAND is recognized as a global leader in air disc brake technology, with millions of disc brake axles in service, worldwide, since 1996.

Featuring Haldex
Calipers and Actuators

ULX40 Features

Lightweight with Quality Ride Performance

The lightweight SAF ULX40 allows more payload while delivering the quality and handling control required without the complexity of air-ride.

Independent testing of road conditions and impact on cargo shows that, along with today’s improved packaging material and pallet configurations, the mechanical suspension system performs to the ride quality standards expected by North American on-highway fleets.


40,000 lbs (18,144 kg)

SAF - THE ULX40 System™ is one complete integrated slider axle suspension system

Delivered completely assembled for efficient installation at the OEM and engineered for optimum performance for fleets – comes installed with SAF drum or optional disc brakes.

Qwik Release®
Pin Pull

With 20% less pulling effort than competitive models, one person can easily reposition the slider – also eliminates bound-up pin problems.

SAF X-Series 5.75" Diameter Axle

The optimized design of the 5.75˝ axle brings a 20 lb. weight savings per tandem, and is over 30% more rigid when compared to the standard 5˝ diameter axle.

Slider Sub-Frame

Manufactured with 80KSI yield steel and strategically located crossmembers to resist racking and buckling. Models available to accommodate 1-3/8˝ and 1-5/8˝ pins.


SAF P89 or P89 Plus Air Disc Brakes

Choose either the proven design and genuine value of the P89 air disc brake, or the premium performance and maintenance free design of the P89 Plus with legendary INTEGRAL® rotor/hub and premium sealed bearings.

Featuring Haldex
Calipers and Actuators


Tire Pilot Plus™

Tire Pilot Plus™ not only controls pressure through inflation, but also maintains equal pressure across all wheels and features high pressure relief for overinflated tires.


Air Release Pin Pull

A simple, efficient pin-pull system. The Air Release design is compact, durable, and allows easy manual operation in the event of an air-down situation.

Tire Pilot Plus™

Improve Profitability by Enhancing Tire Life, Fuel Efficiency and Uptime

Optional Tire Pilot Plusnot only controls pressure through inflation, but also maintains equal pressure across all wheels and features high pressure relief for overinflated tires.

The robust design sets it apart from competitive designs with durable components.

Proper Air Pressure is Critical to Tire Life

Full Contact
Optimizes traction, handling and maximizes tire life.

Outside Contact
Accelerates irregular tread wear, increases rolling resistance, and reduces fuel efficiency by up to 2%.

Center Contact
Only reduces tire life and traction. Tire is susceptible to tread damage and punctures.

Introduction to Tire Pilot Plus™

Installation Procedures

Troubleshooting Procedures

Ride Quality

Enhanced Performance

The SAF springs provide enhanced ride quality and handling control without the complexity of air-ride while still meeting the demands of most fleet operations.

Cargo Protection Analysis

A scientific study on the effects of vibration transmitted into differing loads. The study compares the results of using an air ride versus a mechanical spring ride suspension.

“… there was some concern at first of taking air bags off the trailers that they [our customers] wouldn’t get their furniture in the same condition as before, but we proved them wrong on that and they are very happy…”

Black Armour™

The Most Advanced Suspension Corrosion Protection Available!

Black Armour™

Standard on all SAF Suspensions

Protect your fleet and your bottom line when you spec a ULX40 series suspension system that comes standard with the exclusive Black Armourª corrosion protection treatment.

This advanced corrosion protection gives you the ultimate defense against rust and corrosion.

… Only from SAF-HOLLAND

  • Factory applied on ALL ULX suspensions
  • Weighs and cost significantly less than hot-dip galvanization
  • Can be used as a finish coat or a primer

A Unique Chemical Treatment – Not Just Another Paint or Coating!

Black Armour™ metal treatment is the perfect foundation for fleets that want to add their own topcoat. It can act either as a topcoat, or a primer for nearly any topcoat, all without additional sanding or prep work.

Black Armour™ is a water-based zinc-free coating with 72% fewer solvents than traditional coatings and fewer VOCs!

Black Armour™ is not just a paint – it grafts with metal to form a protective skin that will not shrink or peel, and is impervious to moisture and today’s harsh, anti-icing agents. Unlike paints and powder-coats, Black Armour™ prevents rust creep should chipping occur.

Support Literature

Maintenance & Warranty

Simple and Easy Maintenance

Fewer components mean it’s easier to maintain, and routine inspections are quick and easy:

  •  No shocks
  •  No air spring
  •  No height control valves
  •  No dock lock devices required

Studies show, a fleet of 500 trailers with composite springs can see an average savings of $325,000 over a 10 year period.

10-Year Durasystem™ Warranty Coverage*

The industry’s first and only 10-year suspension and axle system warranty.*

For the first time fleet operators can receive the extra value of a suspension and axle system that is covered for a full ten years.

* This full system coverage includes the mechanical slider assembly, SAF X-Series 5.75″ axles, welded bracketry, and axle connections.

Looking for P89, P89 Plus Disc Brakes or Disc Brake Parts?