PULLMAN axle shock absorber – Cheval Liberté, Debon | KNOTT 990082

Product detailed description

Original KNOTT 990082 shock absorber for PULLMAN / PULLMAN 2

The KNOTT 990082 is an original hydraulic shock absorber for the PULLMAN / PULLMAN 2 independent wheel suspension used on Cheval Liberté and Debon trailers. It works together with the coil spring and the separate wheel suspension arm, forming an important part of the trailer’s suspension system.

This is not a standard universal shock absorber fitted to a trailer axle as an add-on. In the PULLMAN system, the shock absorber is a structural component of the independent wheel suspension and its damping characteristics are matched to this chassis.

For Cheval Liberté and Debon trailers

The KNOTT 990082 shock absorber is used on Cheval Liberté and Debon trailers fitted with PULLMAN / PULLMAN 2 suspension. It is found on Cheval Liberté horse trailers and on Debon cargo, box and other trailers using this type of chassis.

When replacing the shock absorber, check that the existing unit is marked KNOTT 990082 and confirm the suspension type fitted to the trailer.

How does PULLMAN 2 suspension work?

The PULLMAN 2 system uses independent suspension for each wheel. Each wheel is guided by its own articulated arm and suspended by a combination of a coil spring and hydraulic shock absorber.

A typical twin-axle PULLMAN 2 chassis has 4 separate suspension arms, 4 coil springs and 4 shock absorbers. Each wheel responds independently to road bumps, helping reduce the shocks and vibrations transferred to the trailer body.

Benefits of the PULLMAN / PULLMAN 2 system:

• independent suspension for each wheel
• effective suspension using coil springs
• hydraulic damping of each wheel’s movement
• reduced vibrations and impacts transferred to the trailer
• reduced movement of the trailer body
• very good stability and ride comfort
• smoother trailer handling on uneven roads

What the KNOTT 990082 shock absorber does

The coil spring and shock absorber perform different functions in the PULLMAN system. The spring cushions the wheel, while the KNOTT 990082 shock absorber controls and damps the movement of the suspension arm.

After the wheel passes over a bump, the shock absorber prevents the spring from continuing to oscillate and helps keep the wheel movement under control. Properly functioning shock absorbers therefore contribute significantly to stable and smooth trailer handling.

Precise KNOTT 990082 dimensions

The shock absorber dimensions are based on the KNOTT technical drawing. Lengths are measured between the centres of the mounting holes.

• mounting-hole spacing – shock absorber compressed: 185 ± 2 mm
• mounting-hole spacing – shock absorber extended: 277.5 ± 2 mm
• working stroke / extension: 92.5 mm
• mounting holes: Ø 12 mm
• shock absorber body diameter: Ø 32.5 mm
• outer sleeve diameter: Ø 42 mm
• mounting eye radius: R 15.25 mm

The mounting-eye bushes allow angular movement, helping the shock absorber operate without unwanted stress as the independent suspension arm moves.

Technical data

• manufacturer: KNOTT
• original number: 990082
• type: hydraulic wheel-suspension shock absorber
• suspension: PULLMAN / PULLMAN 2
• application: Cheval Liberté, Debon
• mounting-hole spacing – compressed: 185 ± 2 mm
• mounting-hole spacing – extended: 277.5 ± 2 mm
• working stroke: 92.5 mm
• mounting holes: Ø 12 mm
• shock absorber body diameter: Ø 32.5 mm
• outer sleeve diameter: Ø 42 mm
• sales unit: 1 piece

How many shock absorbers does a trailer need?

Each independently suspended wheel in the PULLMAN system uses one shock absorber. A twin-axle trailer with four independently suspended wheels therefore uses a total of 4 KNOTT 990082 shock absorbers.

When replacing one worn shock absorber, we recommend checking the other shock absorbers on the trailer as well. On an older chassis with similar mileage on all components, consider replacing them at least in pairs on the relevant axle, or replacing all four depending on their condition.

When should the shock absorbers be checked?

We recommend checking the shock absorbers regularly along with the other PULLMAN chassis components. An inspection or replacement may be needed if you notice:

• oil leaking from the shock absorber
• mechanical damage or deformation of the shock absorber
• damage to the mounting eyes or their bushes
• significantly more trailer bouncing after travelling over a bump
• impacts or unusual noises from the suspension
• noticeably weaker damping than at the other wheels

Check the complete PULLMAN suspension when replacing a shock absorber

The shock absorber is only one part of the independent suspension. When replacing it, we recommend also checking the coil spring, suspension arm, suspension-arm bush, mounting bolts and shock absorber bushes.

Play or damage in any of these components can affect the suspension and the performance of the new shock absorber.

Original KNOTT replacement part

The KNOTT 990082 is the correct replacement for the same type of shock absorber used in the PULLMAN / PULLMAN 2 suspension on Cheval Liberté and Debon trailers. Using the correct shock absorber is important for it to work properly with the spring and independent suspension arm.

The product is supplied as 1 shock absorber. We also offer KNOTT 990082 sets of 2 or 4 shock absorbers for servicing the complete suspension.

KNOTT 990082 technical drawing