|
|
Content .. 1013 1014 1015 1016 ..
3. Verify that there is no noticeable slip, noise or vibration. Manual First 1. With the vehicle stopped, move the gear selector to FIRST. 2. Accelerate the vehicle to 32 km/h (20 mph). 3. Verify the following: No upshifts occur. The TCC does not apply. There is no noticeable slip, noise, or vibration. Manual Second 1. With the vehicle stopped, move the gear selector to SECOND. 2. Accelerate the vehicle to 57 km/h (35 mph). 3. Verify the following: The 1-2 shift occurs. The 2-3 shift does not occur. There is no noticeable slip, noise or vibration. Manual Third 1. With the vehicle stopped, move the gear selector to THIRD. 2. Accelerate the vehicle to 64 km/h (40 mph). 3. Verify the following: The 1-2 shift occurs. The 2-3 shift occurs. There is no noticeable slip, noise or vibration. TORQUE CONVERTER DIAGNOSIS The torque converter clutch (TCC) is applied by fluid pressure, which is controlled by a pulse TORQUE CONVERTER STATOR
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
The torque converter stator roller clutch can have 2 different malfunctions. The stator assembly freewheels in both directions. The stator assembly remains locked up at all times. POOR ACCELERATION AT LOW SPEED If the stator is freewheeling at all times, the vehicle tends to have poor acceleration from a If the engine freely accelerates to high RPM in NEUTRAL, you can assume that the engine and POOR ACCELERATION AT HIGH SPEED If the stator is locked up at all times, performance is normal when accelerating from a standstill. If the converter has been removed, you can check the stator roller clutch by inserting a finger into NOISE You may notice a torque converter whine when the vehicle is stopped and the transmission is in Perform a stall test to make sure the noise is actually coming from the converter: 1. Place your foot on the brake. IMPORTANT: Do not confuse this noise with pump whine noise, which is usually noticeable in PARK, NEUTRAL and all other gear ranges.
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
2. Put the gear selector in DRIVE. 3. Depress the accelerator to approximately 1,200 RPM for no more than six seconds. A torque converter noise will increase under this load. TORQUE CONVERTER CLUTCH SHUDDER The key to diagnosing TCC shudder is to note when it happens and under what conditions. TCC shudder which is caused by the transmission should only occur during the apply or the IF SHUDDER OCCURS DURING TCC APPLY OR RELEASE If the shudder occurs while the TCC is applying, the problem can be within the transmission or Something is not allowing the clutch to become fully engaged. Something is not allowing the clutch to release. The clutch is releasing and applying at the same time. One of the following conditions may be causing the problem to occur: Leaking turbine shaft seals A restricted release orifice A distorted clutch or housing surface due to long converter bolts Defective friction material on the TCC plate IF SHUDDER OCCURS AFTER TCC HAS APPLIED If shudder occurs after the TCC has applied, most of the time there is nothing wrong with the The TCC is not likely to slip after the TCC has been applied. Engine problems may go unnoticed NOTE: You may damage the transmission if you depress the
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
transmission. Once TCC is applied, there is no torque converter (fluid coupling) assistance. Engine or driveline Inspect the following components in order to avoid misdiagnosis of TCC shudder. An inspection Spark plugs-Inspect for cracks, high resistance or a broken insulator. Plug wires-Look in each end. If there is red dust (ozone) or a black substance (carbon) Coil-Look for a black discoloration on the bottom of the coil. This indicates arcing while Fuel injector-The filter may be plugged. Vacuum leak-The engine will not get a correct amount of fuel. The mixture may run rich or EGR valve-The valve may let in too much or too little unburnable exhaust gas and could MAP/MAF sensor-Like a vacuum leak, the engine will not get the correct amount of fuel for Carbon on the intake valves-Carbon restricts the proper flow of air/fuel mixture into the Flat cam-Valves do not open enough to let the proper fuel/air mixture into the cylinders. Oxygen sensor-This sensor may command the engine too rich or too lean for too long. Fuel pressure-This may be too low. Engine mounts-Vibration of the mounts can be multiplied by TCC engagement. Axle joints-Check for vibration. Thorttle position (TP) Sensor-The TCC apply and release depends on the TP Sensor in Cylinder balance-Bad piston rings or poorly sealing valves can cause low power in a Fuel contamination-This causes poor engine performance. Replace the torque converter if any of the following conditions exist:
2008 Chevrolet Silverado 1500 2008 TRANSMISSION Automatic Transmission - 4L60-E/4L65-E/4L70-E - Cab & Chassis Sierra, Cab & Chassis Silverado, Sierra & Silverado
Content .. 1013 1014 1015 1016 ..
|
|
|