Automatic Transmission - 4L60-E/4L65-E - Overhaul & Testing: Diagnosis Chevrolet TrailBlazer I

TROUBLE SHOOTING

Note. For testing and diagnostic procedures of electronic components, see HYDRA-MATIC 4L60-E ELECTRONIC CONTROLS article.

Inspection

A visual inspection of torque converter may reveal converter is Blue from overheating. If torque converter has been removed from vehicle, stator roller clutch can be checked by inserting a finger into splined inner race of roller clutch and attempting to rotate race in both directions. Inner race should rotate freely clockwise, but should not rotate or should be difficult to rotate counterclockwise.

Torque converter must be replaced for any of the following reasons

1. Damage To Pump Assembly
2. Metal Particles Present In Oil
3. Leaks In Hub Weld Area
4. Hub Scored Or Damaged
5. Stator Failure
6. Torque Converter Imbalance
7. Engine Coolant Contamination
8. Excessive End Play

1. Inspect all valves, springs, sleeves and bushings for chips, burrs, distortion and free movement in bores. Check pressure relief check ball and spring for damage and distortion. Low line pressure will result if check ball and spring are damaged.
2. Inspect pump cover screen and "O" ring for wear and damage. Clean pump body and cover. Check all bores for obstructions. Inspect mating sides of cover and body for scoring, flatness and damage between channels. Check channels for dirt and damaged passages. Inspect stator shaft and pump body bushings for damage.
3. Inspect rotor and slide for scoring, cracks and damage. Check rotor guide and pump vane rings for excessive wear and damage. Inspect all seals for damage.
4. Measure pump rotor and slide thickness for surface wear. Rotor and slide measurements must fall into same thickness range. See «OIL PUMP COMPONENT THICKNESS»(ref-156199-S39294006492003071000000) table. If rotor and slide measurements do not fall into same thickness range, or are outside of all ranges, oil pump must be replaced as an assembly.

OIL PUMP COMPONENT THICKNESS

1. Inspect sprag assembly for weak or damaged springs and retainers and worn rollers. Inspect overrun clutch hub for spline damage, excessive wear and open oil passages. Inspect retainer and race for spline damage, surface wear and damaged ring grooves.
2. Replace sprag assembly if damaged. Inspect forward clutch race for spline damage, excessive wear and open oil passages. Inspect input shaft and housing for spline damage, wear and open oil passages.
3. Inspect 3 sealing check balls located in rear of turbine shaft for tightness. Turbine shaft contains one open lubrication hole. Ensure orifice cup plug is installed. Inspect turbine shaft seal areas for roughness and burrs.
4. Inspect check ball located in input housing for free operation. Inspect pistons for wear, damage and porosity. Inspect spring assemblies for damage and distortion.
5. Inspect steel and composition plates for damage. Inspect snap rings for distortion and damage. Check backing plates for flatness and distortion. Inspect clutch apply rings for distortion and damaged tangs.
6. Inspect forward clutch housing check ball for proper operation (if equipped). Inspect housing for cracks and damage in seal areas. Inspect bearings for excessive wear, flatness, damage and flat rollers.

Scheme 95

Scheme 96

Scheme 97

Scheme 98

Scheme 99

Scheme 100

Scheme 101

Scheme 102

1. Install the forward sprag assembly (642) into the forward clutch outer race (644). (Scheme 97)
2. Install the sprag assembly retainer rings (643) into the forward clutch sprag assembly (644). (Scheme 98)
3. Install the forward sprag clutch inner race and input sun gear assembly (640) into the forward sprag and outer race assembly. (Scheme 99)
4. Install the overrun clutch hub (639) onto the sprag clutch inner race and input sun gear assembly (640). Install the overrun clutch hub retaining snap ring (638). (Scheme 100) NOTE: If the forward clutch sprag assembly operates backwards, you have installed the sprag backwards. Reassemble the sprag correctly. Test the forward clutch sprag assembly for proper operation. Position the forward clutch sprag assembly with the input sun gear facing up. (Scheme 101)
5. Important The sun gear should only rotate in a counterclockwise direction. Hold the forward sprag clutch outer race with one hand and rotate the input sun gear with the other hand. Install the forward clutch sprag and input sun gear assembly into the input clutch housing. Index the overrun clutch hub into the overrun clutch plates. (Scheme 102)

Disassembly & Inspection

Remove inner race and snap ring. Remove roller clutch assembly. Check inner race for damage and surface finish. see scheme 59 Inspect roller and springs for damage and distortion. Inspect support for loose cam, cracks and damaged surface finish. Replace damaged parts as necessary.

Inspect all pistons for porosity and damage. Check for ring groove damage and servo bore in case for any wear which may cut servo seals. Check all springs and oil seal rings for distortion and damage.

Inspect valves and sleeves for scoring and cracks. Ensure valves move freely in bores. Inspect valve body for cracks and scored bores. Inspect machined surfaces for damage. Inspect springs for damaged coils. Replace damaged parts as necessary.

Cleaning & Inspection

Clean transmission case and dry with compressed air. Inspect case assembly for damage, cracks and damaged bolt hole threads. Inspect valve body surface for flatness and land damage. Check case oil passages for restrictions and blockage. Blow compressed air through all case passages. (Scheme 103) Inspect case internal clutch plate lugs for damage and wear. Inspect servo and accumulator bores for damage. Inspect all snap ring grooves for damage.

Scheme 103

1. Clean all parts and dry with compressed air. Inspect reaction and input carriers for pinion gear damage, excessive wear and improper staking of pinion pins. Inspect carrier bearings for heat damage, flatness and roller condition. Place output shaft sleeve inside reaction carrier and input carrier.
2. Rotate sleeve and note smoothness of bearing operation. Replace carrier assembly if roughness is felt. Check pinion gear end play on reaction and input carriers. (Scheme 104)
3. Pinion gear end play should be.008-.024" (.20-.61 mm). Inspect internal reaction gear and support for cracks and damaged splines. Inspect low-reverse clutch plates for wear and signs of excessive heat.
4. Inspect low-reverse clutch piston for roughness or damage in seal ring area. Inspect retainer ring and spring assembly for damage. Inspect sun and internal gears and supports for spline and bushing wear and damage. Replace damaged parts as necessary.

Scheme 104

Clean all parts and dry with compressed air. Inspect 1-2 and 3-4 accumulator parts for damage to pistons or housing. Inspect for flatness and condition of accumulator, oil passage plate and gasket. Inspect wiring harness leads and connectors for damage. Inspect speed sensor rotor teeth for damage and distortion.