Hi Problem with the gearbox: Reverse (R) gear does not move the vehicle and puts no load on the engine. The issue started right after the engine stalled due to a poor battery terminal connection. After checking the terminals, the engine started, but there is a problem with the gearbox. The symptoms: Drive (D): It shifts into 1st forward gear, puts a load on the engine, and the vehicle moves. However, as the RPMs rise, it drops into neutral. When 1st gear engages, pressure P1 is equal to pressure P7. Reverse (R): Reverse engages, but it puts no load on the engine and the vehicle does not move. Pressure P1 is equal to pressure P6. Diagnostic done: X1/A1 plug/connector test – Passed. Pressure metering test – Passed, but the torque converter (turbine) pressure is 0.2 MPa lower than it should be. The machine does not have a Contronic display. Hope we find machine where we can take it to see data by gearbox. Does anyone have experience with this? I suspect an internal mechanical failure in the gearbox, but the preceding electrical issue makes diagnosing it confusing. My next plan is to drop the oil pan (sump) and check the suction filter. Test results are attached.
Update on the situation: Contronic Display: installed, and it is showing the message: "Gear selector ER". Gearbox Oil & Filter: I have drained the gearbox oil and removed the suction filter. Found metal shavings and friction debris inside the filter.
I've encountered this problem before, and I'll tell you about some things I want you to check at the beginning. When you put in R or D gear without starting the engine , I want you to check the voltage coming from the load sensor on the diesel pump. The load sensor contains three lines : power 5v ,ground and single ; You must ensure that 5 volts are available between the power line and the ground on load sensor , Signal and ground line 0.8 volts on idle and 3,8 volts on high idle Because if the voltage on the signal line is higher than 0.8 volts at idle, the transmission understands that the engine speed is higher than 700 rpm and therefore will not engage any gears.
Machine engages 1st gear and can move, also engages R gear (contronic display shows it and pressures coming up in R gear pressure measuring port) but dosent move...maybe you can notice very slow and little moving. TCM pinout test passed and also gear selector, TCM, load sensor are swapped with other machine - all components working well.
I fear your transmission is toast based on the metal fillings and friction debris in the suction filter...
Does anybody have a 5HP500 transmission parts and repair manual?