Allison, along with German refuse service company Frankfurter Entsorgungs-und Service (FES) has subjected its fully automatic transmissions to a rigorous seven-year test to prove longevity and reliability using a fully synthetic TES-295 fully synthetic transmission fluid (in this case, Castrol TranSynd,) demonstrating the extended service intervals and positive effect on vehicle uptime, maintenance and operating cost.
After approximately seven years and more than 14,000 hours of operation per truck, FES reported that the Allison fully automatic transmissions ran virtually free of wear and tear, and without needing a single oil change.
The FES fleet comprises about 100 vehicles fitted with Allison transmissions driven with TES-295 fluid.
For the seven-year test, eight Mercedes-Benz Econic rear loaders equipped with OM 926 LA engines and Allison 3000 Series transmissions were strictly monitored.
When put into service, each was filled with 32 litres of TranSynd fluid, and then used in normal operation, collecting mainly residual waste, wastepaper and packaging, five days a week on average nine for hours a day.
Every six months each vehicle underwent a thorough inspection: checking the transmission and drivetrain for defects, measuring the oil level, and taking oil samples.
Analysing oil test samples was critical to determining how long the TES-295 transmission fluid could be used in severe-duty applications such as refuse collection.
Based on Allison's recommended service intervals, oil filters were replaced after 3,000 hours of operation, with samples showing that oil viscosity and composition remained constant during the seven-year test phase.
No oil changes were needed, and only six litres of fresh TES-295 fluid were required to compensate for oil loss during filter changes. In total, each vehicle needed only four filter changes, and 24 additional litres of TES-295 transmission fluid during the test.
Once the endurance test was complete, two transmissions were completely disassembled and thoroughly examined to comprehensively check transmission health. One was removed from a vehicle in operation for 14,219 hours and 162,609km; the other for 13,344 hours and 168,141km.
Upon examination transmission parts were still in excellent condition. The torque converter lock-up clutch showed only minimal wear, typical in the stop and go duty-cycle of refuse collection applications, and it was the only component replaced during the re-assembly process.
This extreme use of the TES-295 transmission fluid was only possible because all vehicles were subject to regular, extensive controls during the endurance test. Close monitoring was crucial to ensuring transmission health, as deteriorated fluid can result in insufficient protection from corrosion or reduced shifting quality.
Despite the excellent test results, Allison Transmission recommends waste management fleets change TES-295 fluids such as TranSynd after 240,000km, 6,000 hours or 48 months – whichever occurs first. Compared to conventional mineral oil-based transmission fluids, recommended service intervals for TES-295 fluids are up to 12 times longer.
While no oil changes were necessary during the FES endurance test, a comparable vehicle with 13,300 hours of operation would have required 26 recommended mineral oil changes versus only two recommended oil changes using TranSynd.
“We are happy we took part in this test because it has demonstrated that our fleet can rely on Allison transmissions in combination with TranSynd,” said Uwe Klein, workshop manager at FES.
“The test in Frankfurt went great. We gathered comprehensive data and gained experience while delivering benefits from the extended service intervals to the customer,” said Steve Graddy, service engineer at Allison Transmission, who oversaw the test across the entire period.
“It has been demonstrated that further reductions in life cycle costs can be achieved with the combination of Allison fully automatic transmissions and fully-synthetic TES-295 transmission fluids such as TranSynd,” he added.
