Allison 27101-CTCS Genuine TranSynd Transmission Fluid
This is the only synthetic fluid approved for the Allison transmission and has been specifically designed for Allison by Castrol. This fluid is highly recommended and compatible for all 2001-Current Duramax diesel trucks with Allison transmissions. Dmaxstore has tested this fluid for years in our personal trucks and hundreds of customer trucks. The results are superior with noticeably improved and smoother shifts. There is no need to compromise or experiment with other fluids Transynd is the best choice for your Allison. Gears, bearings, bushings, clutches, thrustwashers and other components benefit from improved viscosity stability and cooler lube oil.