How an agricultural OEM drastically improved leak test Gage R&R, reduced warranty claims

March 3, 2020 | By CTS Admin
A manufacturer of transmissions for agricultural machinery was experiencing an issue with warranty claims due to leaks.

The manufacturer offered a no-nonsense warranty: if a farmer had a problem with a tractor, it went back to the dealership in exchange for another, right off the lot. The faulty machine would then come back to the plant for repair.

On the transmission line, operators and quality engineers had lost all trust in the leak test system which had an estimated Gage R&R of 40%. Worse, the operators tried various tricks to get a pass, such as pressurizing the part faster during the fill phase, running the test repeatedly, or just ignoring fail results altogether.

Not surprisingly, that meant that a growing number of machines with leaky transmissions left the factory.
The issue with the leak test lay with the inherent challenges that come with leak testing large parts with large internal volumes. Internal temperature variation is a constant variable that can impact the reliability and repeatability of a test. The existing leak tester could not adjust for this variability.

The solution: Reduced Gage R&R, decreased warranty claims, improved profitability 

The manufacturer switched to the Sentinel 3520, which has the digital pressure regulation to measure down to one-millionth of a PSI, as well as the sensor sensitivity to compensate for ambient and internal temperature variations that can compromise the test. The digital process signature technology used to control and record each test provided comprehensive data that enabled in-depth reporting on test performance.

The result? Gage R&R fell from 40% to 5%. The new system paid for itself the first time it caught a leaky transmission which the old system would have missed. Warranty claims dropped, profitability improved and brand reputation was restored. The Sentinel 3520 became the specified leak test instrument for the company’s powertrain plants around the world.

Read the full case study for more details, "OEM cuts warranty claims with dramatic improvement to leak test Gage R&R".

A reliable, repeatable solution for large part leak test

Sentinel 3520Many manufacturers struggle with balancing accuracy, cycle time, and Gage R&R at the leak test station-particularly when faced with a leak test with complex requirements like large volume leak test, variable volume, multi-cavity parts, etc. These test scenarios require a precise balance of pressure control, flow range and fill rate to get an accurate reading and meet cycle time requirements, which the Sentinel 3520 delivers.