Laser Cladding. Now available at HVT.

Restoring Load Integrity to CAT 793 Rear Wheel Hub ( 377 – 5230)

Engineering Confidence: Comprehensive Crack Repair for CAT 793 Hubs

When a CAT 793 Rear Wheel Hub (377-5230) was brought in for a standard repair, things escalated quickly. During-repair prep, HVT’s welding team uncovered a 400mm through-crack missed by the initial non-destructive testing (NDT). The clock was ticking and the client already quoted the job meaning they couldn’t afford blowouts or schedule drift.

The challenge? Reinforce the hub without altering the pitch circle diameter (PCD) or bearing alignment. Even small distortion here would have triggered a full hub rebuild. HVT delivered a repair that contained the crack, controlled the heat and protected every critical tolerance.

What went wrong: A hidden crack with real consequences

What looked like a small fracture became a precision repair risk:

  • 400mm crack cutting across the paddle ribs, not covered in the original NDT.
  • Bearing and seal journal alignment threatened by potential distortion.
  • The PCD was at risk, meaning a deformation would require full re-machining of the bolt pattern.

How we fixed it: Careful welding without throwing off alignment

HVT applied a weld sequence engineered for structural stability.

  • Full exposure and tracking of the crack path across ribbing.
  • Reinforcement welds applied using distortion-neutral sequences.
  • Strategic bracing and fixture setup to stabilise the component under heat.
  • Interpass temperature controls maintained throughout.
  • The PCD and bearing seats were protected during every phase of the job. No shortcuts. Just methodical execution by a team experienced in failure-prone drivetrain components.

What came out of it: A clear repair, no rework needed

  • Critical flaw repaired: The 400mm crack fully excavated and structurally closed.
  • Precision held: No shift in PCD, all key fits and alignments remained within spec.
  • Client delivered a field-ready part, no re-machining required.
  • Costs controlled: Repair completed for under 30% of replacement price.

The component passed all final inspections and dimensional checks with no deviation from tolerance. The result: A fully functional hub, returned on time, without budget creep.

Where others weld, HVT engineers solutions

This project was a test of process control, and technical discipline. It proved once again that experienced repair backed by methodical execution can match, and often exceed, the performance of full part replacement.

Got fatigue cracking or alignment-critical drivetrain components under threat? Talk to HVT. We’ll help you catch what others miss, and fix it right the first time.

View More Projects
Contact Us

Contact Our Team

"*" indicates required fields

Max. file size: 100 MB.