Automatic Transaxle Overhaul - 4T40-E/4T45-E: Diagnosis Saturn ION I

Case Inspection

Note. Use J 36850 or equivalent during assembly in order to retain checkballs or to lubricate components. Lubricants other than the recommended assembly lube changes the transmission fluid characteristics and causes undesirable shift conditions or filter clogging.

1. Thoroughly clean the transmission case and all the case threads with solvent.
2. Inspect the case exterior and the external bores for cracks, sharp edges, porosity and excessive bushing wear.
3. Inspect the case interior for damage at the snap ring grooves, case lugs and band anchor pin.
4. Inspect all the gasket surfaces for surface damage and in order to ensure surface flatness.
5. Inspect the corresponding gasket for proper impressions in order to ensure surface flatness.
6. Inspect the bolt holes and fasteners for thread damage. If necessary, repair or replace any bolt holes or fasteners.
7. Air check the oil passages. For identification of the oil passages, refer to the transmission diagnosis section.

Output Shaft Inspect

1. Inspect the output shaft (94) for damage to the splines, snap ring grooves and the journals.
2. Clean and dry the output shaft.

Oil Pump Cleaning and Inspection

1. Inspect the bearing on the flange for excessive wear or damage.
2. Inspect the machined surfaces for scratches or nicks that may cause a fluid leak.
3. Thoroughly flush the oil pump assembly (10) with clean transmission fluid through the pump inlet and outlet passages.
4. Drain excess fluid from the oil pump assembly.