Reyco Granning 79KB Air Suspension

Quick Facts

  • Manufacturer: Reyco Granning
  • Product Series: 79KB
  • Product Type: Rear air-suspension system
  • Suspension Category: Medium-duty and specialty-vehicle air suspension
  • Primary Position: Rear axle
  • Common Axle Configuration: Single rear axle
  • Primary Applications: Buses, recreational vehicles, emergency vehicles, commercial trucks, and specialty chassis
  • Suspension Medium: Air springs
  • Axle Type: Driven or non-driven rear axle, depending on the vehicle
  • Production Status: Application and parts availability depend on model and production year
  • Primary Benefit: Provides controlled air-ride performance for medium-duty and specialty vehicles

Overview

The Reyco Granning 79KB is a rear air-suspension system used in commercial trucks, buses, recreational vehicles, emergency equipment, and specialty chassis. It connects a single rear axle to the vehicle frame while using air springs to support the chassis and payload.

The suspension is designed to provide a smoother ride than many conventional leaf-spring arrangements. Its air springs adjust to changing vehicle loads, while structural suspension members control axle movement and shock absorbers provide damping.

The 79KB designation can cover application-specific configurations with different capacities, ride heights, axle connections, frame brackets, and control systems. Some installations may be older or no longer offered as current original equipment, making the suspension identification tag especially important when ordering parts.

Key Characteristics

  • Single-rear-axle air suspension
  • Designed for medium-duty and specialty chassis
  • Air springs provide primary load support
  • Maintains a consistent chassis ride height
  • Suspension members control axle movement
  • Shock absorbers manage vertical motion
  • Suitable for driven or non-driven axle applications when properly configured
  • Can improve passenger and cargo comfort
  • Supports buses, recreational vehicles, emergency vehicles, and commercial trucks
  • Available in application-specific capacities and ride heights
  • Can be integrated with vehicle kneeling or lowering systems
  • Established service history in specialty-vehicle applications

Major Components

  • Frame brackets
  • Suspension beams or trailing arms
  • Axle mounting brackets
  • Air springs
  • Shock absorbers
  • Pivot bushings
  • Torque-control components
  • Lateral-control rod
  • Height-control valve
  • Ride-height linkage
  • Air lines and fittings
  • Crossmember
  • Rebound-control components
  • Structural fasteners
  • Optional suspension dump controls
  • Optional kneeling or lowering controls

How the Suspension System Works

Compressed air inside the suspension’s air springs supports the frame, body, passengers, cargo, and mounted equipment. When additional weight lowers the chassis, the height-control valve adds air until the vehicle returns to its specified ride height.

When weight is removed, the valve releases excess air. This allows the chassis to remain at a relatively consistent height under changing load conditions.

Suspension beams and axle-control components guide the axle as it moves vertically. These components also control forces created by acceleration, braking, and cornering.

Shock absorbers slow rapid movement and help prevent repeated bouncing. A lateral-control component limits unwanted side-to-side axle movement beneath the frame.

Suspension Position and Function

The 79KB is installed between the vehicle frame and a rear axle. Depending on the application, the axle may be a driven axle on a truck or recreational vehicle or a non-driven axle on certain specialty chassis.

The suspension performs several functions:

  • Supports the rear chassis and payload
  • Maintains the designed ride height
  • Allows controlled vertical axle movement
  • Reduces road shock transmitted into the body
  • Controls axle movement during acceleration and braking
  • Limits side-to-side axle movement
  • Helps maintain tire contact with the road
  • Improves ride consistency between loaded and unloaded conditions
  • Supports stable operation of passenger and specialty bodies

Common Specifications

  • Suspension Type: Rear air suspension
  • Axle Arrangement: Single rear axle
  • Suspension Capacity: Application-specific
  • Ride Height: Determined by the vehicle and suspension configuration
  • Axle Compatibility: Approved driven or non-driven rear axle
  • Damping: Heavy-duty shock absorbers
  • Lateral Control: Application-specific track or torque rod
  • Air Supply: Vehicle compressed-air system
  • Brake Compatibility: Air or hydraulic brakes, depending on the chassis
  • Wheel Configuration: Single or dual rear wheels, depending on the vehicle

Exact capacity, ride height, mounting dimensions, and component specifications must be confirmed using the complete suspension model and vehicle information.

Capacity, Ride Height, and Axle Travel

The 79KB was produced for application-specific vehicle capacities. The suspension must be matched to the axle rating, frame, brakes, tires, wheels, and completed vehicle weight.

Its mechanical capacity does not automatically increase the vehicle’s gross axle weight rating or legal payload. The completed vehicle remains limited by its lowest-rated component and certification.

Correct ride height is necessary for:

  • Full jounce and rebound travel
  • Proper air-spring shape
  • Correct shock-absorber position
  • Stable driveline geometry
  • Axle alignment
  • Tire and body clearance
  • Vehicle handling
  • Consistent floor or loading height

Ride-height specifications should be obtained from the service information for the exact 79KB configuration.

Ride Quality and Load Distribution

The air springs help isolate the vehicle frame and body from road impacts. This can improve comfort for drivers, passengers, patients, and recreational-vehicle occupants.

A more controlled ride may also reduce vibration affecting:

  • Interior cabinets
  • Medical equipment
  • Passenger seats
  • Cargo restraints
  • Body structures
  • Electronic equipment
  • Chassis-mounted components

The 79KB supports one rear axle and does not equalize weight between tandem axles. Proper passenger, cargo, fuel, water, and equipment placement remains necessary.

Suspension Controls and Adjustment Options

The 79KB normally uses a height-control valve to maintain the specified chassis position. Application-specific vehicles may include additional controls.

Possible control functions include:

  • Mechanical height-control valve
  • Manual suspension dump
  • Automatic suspension dump
  • Temporary kneeling function
  • Loading-height adjustment
  • Automatic leveling
  • Low-air warning
  • Dash-mounted suspension control
  • Body-equipment interlocks
  • Emergency inflation connection

Suspension controls should only be used according to the vehicle and suspension manufacturers’ instructions. The vehicle should normally return to its specified ride height before road operation.

Alignment and Suspension Geometry

Correct rear axle alignment helps control tire wear, vehicle tracking, and driveline vibration. The axle must remain square with the frame and correctly centered beneath the chassis.

Suspension beams, pivot bushings, axle connections, and lateral-control components maintain this geometry. Worn or loose components can allow the axle to shift during braking, acceleration, or cornering.

Alignment should be checked after:

  • Suspension-bushing replacement
  • Axle replacement
  • Frame repair
  • Ride-height adjustment
  • Collision damage
  • Severe curb impacts
  • Changes to the body or equipment
  • Appearance of irregular tire wear

Ride height should be verified before final alignment measurements are taken.

Axle, Brake, and Wheel-End Options

The 79KB suspension can be integrated with application-specific rear axles and brake systems.

Possible equipment includes:

  • Single rear drive axle
  • Non-driven rear axle
  • Single-reduction drive axle
  • Air drum brakes
  • Air disc brakes
  • Hydraulic disc brakes
  • Hydraulic drum brakes
  • Single rear wheels
  • Dual rear wheels
  • Conventional wheel ends
  • Unitized hub systems
  • Antilock braking equipment
  • Automatic lubrication systems

The installed suspension, axle, brakes, tires, and wheels must be identified before replacement components are ordered.

Common Applications

  • Transit buses
  • Shuttle buses
  • School buses
  • Recreational vehicles
  • Motorhomes
  • Ambulances
  • Emergency vehicles
  • Commercial straight trucks
  • Delivery trucks
  • Service vehicles
  • Mobile medical units
  • Specialty vocational chassis
  • Passenger-carrying commercial vehicles
  • Vehicles carrying sensitive equipment

Vehicle, Axle, and Frame Compatibility

The 79KB must be matched to the exact frame, rear axle, brake system, ride height, and vehicle application.

Compatibility depends on:

  • Vehicle manufacturer
  • Model and model year
  • Frame width and rail strength
  • Wheelbase
  • Rear axle model
  • Rear axle rating
  • Suspension capacity
  • Designed ride height
  • Brake system
  • Single or dual rear wheels
  • Driveshaft geometry
  • Fuel-tank placement
  • Battery-box location
  • Exhaust-system clearance
  • Body and floor structure
  • Completed vehicle weight distribution

A suspension should not be substituted solely because its rated capacity appears similar. Mounting geometry and structural loads must also be evaluated.

Advantages

  • Improved ride quality compared with many leaf-spring suspensions
  • Consistent chassis height as vehicle loading changes
  • Reduced shock transmitted into the body
  • Improved passenger and occupant comfort
  • Can help protect sensitive equipment
  • Supports application-specific commercial chassis
  • Air springs adjust to normal load changes
  • Provides controlled rear axle movement
  • May support kneeling or lowering functions
  • Can reduce stress on body and interior components
  • Suitable for driven and non-driven axle applications when properly configured

Limitations or Considerations

  • Requires a dependable compressed-air supply
  • Air leaks can lower the chassis
  • Ride height requires periodic inspection
  • Shock absorbers and bushings are wear components
  • Specifications vary between 79KB applications
  • Some configurations may be legacy products
  • Older identification tags may be damaged or missing
  • Replacement components must match the exact suspension
  • Does not increase the vehicle’s certified weight ratings
  • Improper ride height can cause driveline vibration or component interference
  • Specialty body equipment may restrict suspension clearance

Driver and Operator Experience

Drivers and passengers may notice less vibration and harshness than in a comparable vehicle using a conventional mechanical rear suspension.

The ride can remain more consistent as passengers, cargo, fluids, or equipment are added because the air system returns the chassis to its specified height.

Operators should report:

  • Vehicle leaning to one side
  • Rear chassis sitting too low
  • Slow suspension inflation
  • Frequent compressor cycling
  • Excessive bouncing
  • Unusual clunking
  • Poor vehicle tracking
  • Driveline vibration
  • Irregular rear tire wear

Maintenance and Ownership Notes

  • Inspect air springs for cracks, cuts, abrasion, and leaks.
  • Check air lines, fittings, reservoirs, and valves.
  • Measure ride height at scheduled intervals.
  • Inspect height-control valve linkage.
  • Check shock absorbers for leakage and damaged mounts.
  • Inspect pivot bushings and suspension beams.
  • Check lateral-control rods and their bushings.
  • Inspect frame and axle brackets for cracks.
  • Verify critical fastener torque.
  • Monitor tires for alignment-related wear.
  • Check driveline angles after suspension changes.
  • Maintain the compressor, air dryer, and reservoirs.
  • Test kneeling or lowering controls when equipped.
  • Inspect the suspension after overloading or severe impacts.
  • Use the correct service information for the identified configuration.

Common Suspension Problems

  • Air leaks: Damaged air springs, hoses, fittings, valves, or reservoirs may cause the chassis to settle.
  • Incorrect ride height: A faulty height-control valve, damaged linkage, restricted air line, or improper adjustment can reduce suspension travel.
  • Vehicle leaning: Uneven loading, air restrictions, valve problems, or damaged suspension components can cause side-to-side height differences.
  • Excessive bouncing: Worn shock absorbers, incorrect ride height, damaged air springs, or improper loading can reduce suspension control.
  • Worn pivot bushings: Bushing wear can allow axle movement, create noise, and contribute to alignment problems.
  • Driveline vibration: Incorrect ride height or shifted axle position can change driveshaft operating angles.
  • Irregular tire wear: Misalignment, worn bushings, tire-pressure differences, or wheel-end problems may be responsible.
  • Structural cracking: Corrosion, impacts, overloading, loose fasteners, or improper repairs can damage suspension brackets.
  • Difficulty finding parts: Older configurations may require the original suspension number, vehicle build records, and component measurements.

Identification Information

Identification information may be located on a tag attached to the suspension assembly, frame bracket, axle, or vehicle chassis.

Record the following information:

  • Vehicle manufacturer
  • Vehicle identification number
  • Vehicle model and model year
  • Complete suspension model
  • Suspension serial or assembly number
  • Rated suspension capacity
  • Designed ride height
  • Rear axle manufacturer and model
  • Rear axle rating
  • Brake type
  • Wheel configuration
  • Air-spring part number
  • Shock-absorber part number
  • Height-control valve number
  • Frame and axle bracket arrangement

If the identification tag is missing, component numbers, measurements, photographs, and vehicle build records may be required.

Buying Considerations

  • Confirm that the suspension is a 79KB configuration.
  • Record the complete model and serial information.
  • Verify the suspension’s rated capacity.
  • Match the required ride height.
  • Confirm frame and axle compatibility.
  • Check driven or non-driven axle requirements.
  • Match the vehicle’s brake system.
  • Verify single- or dual-wheel configuration.
  • Review replacement-parts availability.
  • Determine whether the suspension is still supported.
  • Inspect used systems for cracks, corrosion, and altered brackets.
  • Check air springs, shocks, bushings, and control valves.
  • Compare repair costs with replacement or suspension conversion.
  • Use a suspension shop familiar with specialty-vehicle applications.

Variants and Configurations

The 79KB designation may include different application-specific arrangements.

Configuration differences may include:

  • Suspension capacity
  • Ride height
  • Frame width
  • Axle type
  • Driven or non-driven axle
  • Single or dual rear wheels
  • Air or hydraulic brakes
  • Drum or disc brakes
  • Frame-bracket design
  • Suspension-beam configuration
  • Air-spring specification
  • Shock-absorber placement
  • Height-control system
  • Kneeling or lowering controls
  • Vehicle manufacturer integration

The complete model number should be used when comparing suspensions or ordering parts.

Comparison to Similar Equipment

Compared with the Reyco Granning 102AR Air Suspension, the 79KB uses a different suspension architecture and application range. Capacity, ride height, brackets, and components should not be assumed interchangeable.

Compared with the Reyco Granning 240AR Air Suspension, the 79KB is associated with a single rear axle. The 240AR is intended for tandem rear-axle applications.

Compared with the Link UltraRide Suspension, both may serve medium-duty and specialty vehicles. The correct choice depends on the chassis, axle, capacity, ride height, and original vehicle design.

Compared with a conventional leaf-spring suspension, the 79KB generally provides better unloaded ride quality and more consistent chassis height. A leaf suspension may have fewer air-system components.

Best Fit For

  • Vehicles originally equipped with a Reyco Granning 79KB
  • Buses requiring improved passenger comfort
  • Recreational vehicles and motorhomes
  • Emergency medical vehicles
  • Commercial straight trucks
  • Specialty vehicles carrying sensitive equipment
  • Vehicles with changing passenger or cargo loads
  • Fleets maintaining older air-suspended equipment
  • Applications requiring consistent chassis height
  • Operators with access to appropriate suspension service support

Related Vehicle and Trailer Types

  • Class 6 vs Class 7 vs Class 8 Trucks
  • Commercial straight trucks
  • Transit buses
  • Shuttle buses
  • School buses
  • Recreational vehicles
  • Ambulances
  • Emergency vehicles
  • Delivery trucks
  • Service vehicles
  • Specialty commercial chassis

Related Truck and Trailer Models

Related Suspension Types

Related Equipment Systems

Related Guides

Regulatory and Compliance Notes

The suspension’s mechanical capacity does not override the vehicle’s gross axle weight rating, gross vehicle weight rating, tire capacity, wheel capacity, brake rating, or legal road-weight limits.

Suspension changes must preserve safe brake, steering, driveline, fuel-system, electrical, and body operation. Frame modifications should follow approved engineering procedures.

Passenger buses, ambulances, recreational vehicles, and specialty vehicles may be subject to additional construction, accessibility, emergency-equipment, and final-stage manufacturing requirements.

Changes to ride height or kneeling controls should not interfere with vehicle stability, tire clearance, driveline geometry, or required ground clearance.

Real World Operating Notes

Many 79KB systems may now be found on older or specialized vehicles. Identification can be more difficult when tags have been painted over, damaged, or removed.

Vehicle body weight should be considered carefully. Passenger interiors, medical equipment, water tanks, generators, slide-outs, lifts, and storage compartments can significantly change rear axle loading.

Ride-height problems should be corrected before diagnosing alignment or driveline vibration. A vehicle aligned at the wrong height may still track poorly after normal ride height is restored.

Replacement air springs should be selected using the exact suspension configuration. A physically similar air spring may have different operating dimensions or load characteristics.

Frequently Asked Questions

What is the Reyco Granning 79KB?

The 79KB is an application-specific rear air suspension used on commercial trucks, buses, recreational vehicles, emergency vehicles, and specialty chassis.

Is the 79KB a front or rear suspension?

It is primarily a rear suspension designed for a single rear axle.

Does the 79KB use air springs?

Yes. Air springs support the chassis and help isolate the vehicle body from road shock.

Is it used with driven or non-driven axles?

The axle arrangement depends on the vehicle. Application-specific systems may be used with driven or non-driven rear axles.

Does the suspension increase vehicle capacity?

No. The vehicle remains limited by its certified axle, frame, brake, tire, wheel, and gross vehicle weight ratings.

Why is the ride height important?

Correct ride height preserves axle travel, air-spring shape, shock position, driveline angles, alignment, and tire clearance.

What causes a 79KB-equipped vehicle to lean?

Possible causes include an air leak, restricted line, faulty height-control valve, uneven loading, incorrect adjustment, or damaged suspension components.

Are all 79KB parts interchangeable?

No. Component differences may exist between capacities, ride heights, axles, and vehicle applications.

Is the 79KB still available?

Availability depends on the exact configuration. Some systems may be legacy products supported primarily through replacement parts.

How can the correct replacement parts be identified?

Use the suspension tag, vehicle VIN, ride height, axle information, and individual component numbers.

Availability and Where to Find

The Reyco Granning 79KB may be found on existing buses, recreational vehicles, emergency vehicles, commercial trucks, and specialty chassis.

Replacement air springs, shocks, bushings, valves, torque rods, and mounting components may be available through Reyco Granning distributors, commercial-vehicle dealers, bus and recreational-vehicle parts suppliers, suspension specialists, and heavy-duty repair facilities.

Because some configurations may be older, buyers should confirm whether original components have been superseded. The complete suspension model, ride height, axle information, and vehicle VIN should be recorded before ordering.

Current technical support, parts information, and distributor resources are available through the Reyco Granning website.

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