In Chinas trucking industry it has long been common to use a single, standard lubricant for both transmissions and axles. Some say the practice no longer provides adequate protection in modern heavy-duty trucks, but industry sources suggest operators may be slow to change their habits.
At a recent press conferencein Beijing, Zhao Jiandong, head of market development at PetroChina, said developments in logistics have created new challenges in China for heavy-duty trucks, which now have to carry more goods, go longer distances and experience more difficult road and weather conditions.
New generations of heavy-duty trucks have been designed to adapt to these trends, and these trucks require us to use specific gear oils for transmissions and axles to ensure optimal performance, Zhao said.
Zhao noted that Chinese heavy-duty truck operators typically use gear oils meeting the American Petroleum Institutes API GL-5 specification as a transmission fluid and axle fluid. But the number of equipment problems is growing, he suggested, and PetroChina believes the trend stems from inadequate performance by API GL-5 fluids. PetroChina conducted research showing that approximately 40 percent of manual transmission problems involve a gear synchronizer. API GL-5 simply cannot provide the stable and controlled friction performance that synchronizer requires, Zhao said.
He added that new trucks increasingly have aerodynamic designs that raise manual transmission temperature by at least 25 degrees Celsius, and that this requires gear oils with a high level of thermal oxidation stability. But GL-5 is too active for that, causing excessive amount of residue under high temperature.
To try to address the issue, PetroChina introduced two new gear oils – MTF18 and GL-5+ – designed specifically for manual transmissions and axles. Both products are marketed under PetroChinas Kunlun brand. According to Zhao, Kunlun GL-5+ is an upgraded version of API GL-5 and has passed a 100,000-kilometer test by Chinas for major truck manufacturers Dongfeng Motor and FAW Jiefang Automotive.
But satisfying original equipment manufacturers is only part of the equation. Chinese truck operators would also have to be convinced of the need to use different lubes for transmissions and axles. This is not easy.
As long as drivers use lubes from the same manufacturer, there shouldnt be any problem, a repair worker at Hubei province-based Aiben group, a heavy-truck maintenance service provider for the logistics industry, told Lube Report Asia. I never heard of transmissions and axles needing to use different lubes.
An engineer from Beijing-based truck manufacturer Foton Daimler expressed similar sentiments.
I dont think its necessary to use two different gear oils. We always suggest 85W-90 gear oils for clients, he said.
Dongfeng and Foton Daimler both sell their own genuine gear oils. ExxonMobil and Shell are major suppliers of axle gear oils in the Chinese market.