What is the Hendrickson ULTIMAAX?
ULTIMAAX is Hendrickson’s severe-duty rear rubber suspension. The manufacturer describes walking-beam technology combined with progressive-rate springs and lists several capacity variants. This is a different suspension type from the PRIMAAX EX rear air system, despite both serving demanding vocational roles.
What matters in a comparison
For ULTIMAAX, identify the exact rating and axle spacing before comparing vehicles. Ask whether the body and working conditions match the documented application approval. Distinguish a site-travel rating from the truck’s ordinary road-loading limits. For used equipment, have the suspension and surrounding chassis assessed together; a catalogue capacity does not establish the condition of its springs, beams or connections.
Questions to take to the supplier
- What exact rating and axle spacing are documented?
- Which body and application were approved?
- Is a qualified chassis-condition assessment available?
Sources & limits
Manufacturer material supports the identification and overview above. Comparison considerations and supplier questions are Truck University’s original editorial interpretation, prepared with AI assistance. They are not an independent performance test or expert inspection.
Model-family reference only. Availability, specifications and service requirements can differ by year, market and configuration. Verify the actual vehicle or component using its identification and current manufacturer documentation. Do not use this page as a parts-fitment, modification, repair or loading instruction.
Published specifications and examples retain their labelled units; the header preferences apply to calculators.
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