How to Troubleshoot a Nissan Pickup Transmissionby David Marsh
Nissan pickup transmissions manage the transfer of power produced by the engine to the driven wheels. Nissan makes both automatic and manual transmissions. Automatic transmissions change gears through the use of electric pumps and hydraulic fluid, shifting gear-sets at pre-set speeds without driver intervention. Manual transmissions use a manually operated clutch to disconnect the gear box from the engine so that shifts can be made. Troubleshooting both is necessary for the car to stay useful.
Examine the floor of the garage or driveway where you park the vehicle. Transmission fluid looks like cherry cough syrup. Check to see if it's coming from the front of the transmission or the rear. There are two main seals in a transmission. One joins it to the engine. The other joins it to the drive shaft. Leaks can come from either one.
Open the hood when the engine is warm and smell inside. Burned transmission fluid makes a strong odor. Low fluid level, internal slippage caused by mechanical defects or clogged fuel lines can overcook the fluid.
Take the pickup for a drive and listen closely to the transmission. If you hear whirring or buzzing coming from the automatic transmission, there could be a defective torque converter or the fluid level might be low.
Pay attention to the shifting pattern and speeds of the pickup. Shifting should take place at the same engine speed and ground speed under the same driving conditions and go through all of the gears all the time. If the pickup starts shifting at much lower or higher speeds than usual or misses a gear, there is something wrong. This could be caused by a broken vacuum linkage control, broken lines, or band failure.
Look for a sudden gear change into neutral. Does the pickup pop out of a gear? Is it the same gear? If it's the same gear, then it could be a transmission problem. If it's all gears, it might be a bad clutch.
Listen for strange noises when you shift. The synchronizers inside the transmission help match gear speeds so each gear is traveling at the same rate for the shift. They should make each shift quiet and smooth. If you hear grinding in any gear, then the pickup needs to be serviced.
Be aware of the effort it takes to move from gear to gear. The effort should be the same in all gears. A clutch problem can make it hard to move from gear to gear, but it will be the same for each gear change. When it's harder to move from fourth to fifth than it is to move from first to second, there's a problem developing inside the transmission.
Open the hood and check the engine mounts. Look for open breaks or cracks. If the engine shifts, it will move it out of alignment with the transmission.
Ask your mechanic to change the transmission fluid and look for metal shavings which may be in the fluid or clinging onto the drain plug.