Dana: Methods and Techniques for Overhauling Dana Loader Transmissions

　　The transmission of a Dana loader is one of its critical components, connecting the engine to the machine’s drive system. When a malfunction occurs during operation, how should it be repaired? Let’s explore the methods and techniques for servicing a Dana loader’s transmission.

　　 Repair Methods for DeNa Loader Transmissions

　　1. The hydraulic fluid in the transmission increases, while the hydraulic fluid in the reservoir decreases.

　　Cause of failure: The oil seals of the working pump or steering pump have aged, and the axial clearance or radial clearance of the pump shaft in the working pump or steering pump is excessively large.

　　Troubleshooting method: Replace the oil seal of the working pump or the steering pump; repair and inspect the oil pump, or replace the oil pump.

　　2. The hydraulic fluid in the transmission decreases, while the hydraulic fluid in the reservoir increases.

　　Cause of failure: Clogging of the hydraulic tank filter or blockage of the oil pump suction line.

　　Troubleshooting method: Clean or replace the oil filter, and replace the oil pump suction pipe.

　　3. After the transmission shifts to neutral or a gear is engaged, the transmission pressure is low, and the machine as a whole lacks traction.

　　Cause of failure: insufficient power transmission within the transmission, clogged transmission oil pan filter, damaged travel pump, poor volumetric efficiency, improper adjustment pressure of the relief valve or inlet pressure valve, and severe aging, degradation, or bending of the travel pump’s suction pipe.

　　Troubleshooting steps: Add hydraulic fluid to the transmission until it reaches the mid‑level mark at idle; replace or clean the filter; replace the travel pump; readjust the pressure to within the specified range; and replace the oil lines.

　　 Maintenance Procedures for DeNa Loaders

　　1. In the DANA loader’s gear, there is no walking force or it does not move. The remaining gears function normally.

　　Key diagnostic points: When the vehicle is stationary or moving slowly, the driveshaft rotates rapidly and with considerable force. When the engine speed is increased, the driveshaft speed rises in a manner that is clearly disproportionate to the speeds of the front and rear driveshafts. Furthermore, the transmission oil pressure remains normal across all gear ratios; however, once this particular gear is engaged, the pressure drops noticeably.

　　Causes of Denka Loader Malfunctions:

　　1) The bearing cover or nylon ring is severely worn.

　　2) When the bearing cover and nylon ring are in good condition, or when wear is slight, verify that the inner and outer surfaces of the clutch for this gear exhibit poor sealing.

　　Troubleshooting: Replace the damaged bearing cover or nylon ring, as well as the inner and outer sealing rings, and readjust the clearance between the sleeve and the bearing cover.

　　DeNa loader fault analysis: When there is no travel force or the machine fails to move in a particular gear, issues common to all gears—such as those involving the hydraulic torque converter, travel pump, and pressure-reducing valve—can be ruled out. The only potential source of the problem lies in the oil circuit from the shift control valve to the clutch piston for that specific gear. When vulnerable components like bearing caps, nylon rings, and inner/outer sealing rings wear, significant leakage occurs at the worn areas, causing a drop in hydraulic pressure. In neutral or other gears, since oil does not flow through the worn section, the hydraulic pressure remains normal.

　　2. The machine automatically moves forward in neutral, and it can also operate normally when shifted into drive. When in reverse, the machine stops and cannot move. All pressure levels in each gear are normal.

　　DeNa loader malfunction cause: the main and driven plates of the forward clutch have sintered and seized; the forward clutch piston is stuck, and the planetary carrier’s one-way valve is blocked.

　　Troubleshooting procedure: Disassemble the forward clutch, clean the oil passages, replace the driving and driven plates along with any damaged components, clean all relevant parts, replace the cover rings, flush the loose universal check valve, and replace the clutch discs and the inner and outer cover rings. 3. During normal operation of the entire machine, if the second‑gear gear suddenly fails to engage after being selected, verify that the operating pressure for this gear and for all other gears is within the normal range.

　　Cause of the DeNa loader malfunction: The clutch shaft has broken.

　　Troubleshooting method: Replace the clutch shaft and readjust the bearing clearance.

　　3. During operation, the machine shall not accelerate suddenly or reverse; the transmission operating pressure shall be normal.

　　Causes of Denka Loader Malfunctions:

　　1) Fault in the transmission distribution valve, or damage to the accumulators (40F, 50D, 50F); the pneumatic control valve system of the transmission valve is jammed or damaged.

　　2) Death due to blockage of the oil circuit

　　3) Accumulator circuit blockage

　　4) Failure of the pneumatically controlled shut-off valve

　　DeNa loader troubleshooting procedure: Clean the shift valve’s isolation spool or replace the pneumatic control valve to ensure all relevant oil circuits are unobstructed; repair or replace the pneumatic shut-off valve.

　　The above outlines the methods and techniques for servicing a DeNa loader’s transmission. For more information, please feel free to contact us at any time!

Beijing Yihaowei Power Equipment Co., Ltd. specializes in Dana, Dana Spicer, Dana agency services, and Dana repair. Its product lineup includes Dana drive axles, Dana torque converters, Dana transmissions, Clark transmission‑driven axles, and Allison transmission spare parts, among others. Established in 2002, the company obtained authorization from Dana in 2004, becoming one of more than 60 service centers worldwide. Today, we operate one of China’s largest warehouses for powertrain components. Backed by a highly skilled professional team, we provide expert technical support and genuine, high‑quality product solutions to numerous equipment manufacturers, end users, and distributors both domestically and internationally.