Home/GMC/C3500 HD/GMC C3500 HD (1991-2000)/Repair manual/Automatic Trans/Automatic Transmission Overhaul - 4L80-E: Specifications
Contents Wiring diagrams Section: Automatic Trans All sections

Automatic Transmission Overhaul - 4L80-E: Specifications GMC C3500 HD

Automatic Trans 1 illustration ~471 words

No Torque In Reverse & 3rd

Broken forward clutch hub, housing or snap ring.

No Torque In 2nd

Worn or damaged intermediate sprag.

TORQUE CONVERTER

Note. For diagnosing torque converter clutch, see AUTO TRANS DIAGNOSIS - HYDRA-MATIC 4L80-E CONTROLS - 1995 article or AUTO TRANS DIAGNOSIS - HYDRA-MATIC 4L80-E CONTROLS - 1996 article.

TORQUE CONVERTER INSPECTION

Torque converter must be replaced for any of the following reasons.

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

TORQUE CONVERTER STALL SPEED TEST

  1. Torque converter whine is usually noticed when vehicle is stopped and transmission is in Reverse or Drive. Whine will increase when engine RPM is increased and will stop when vehicle is moving or when torque converter clutch is applied. Stall speed test is to ensure whine is coming from torque converter.
  2. Start engine, and allow it to reach normal operating temperature. Apply parking and service brakes. Put transmission in Drive. Depress accelerator to approximately 1200 RPM for less than 6 seconds. DO NOT depress accelerator for more than 6 seconds or transmission damage may occur. Torque converter noise will increase under this load.

Note. Torque converter whine should not be confused with pump whine, which is usually noticeable in Park, Neutral and all other gear ranges. Pump whine will vary with pressure.

TORQUE CONVERTER STATOR CHECK

  1. Torque converter stator roller clutch can either remain locked up at all times or freewheel in both directions. If stator is freewheeling at all times, vehicle tends to have poor acceleration from a stop. Vehicle may act normal at speeds above 30-35 MPH.
  2. If poor acceleration is noted, ensure exhaust system is not blocked, engine timing is correct and transmission is in 1st gear when starting from a stop. If stator is locked up at all times, performance from a stop appears normal. Engine RPM and acceleration is limited at high speeds. Engine may overheat from this condition.
  3. 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 trying to turn race in both directions. Inner race should turn freely clockwise but should not turn or should be difficult to turn counterclockwise.

TORQUE CONVERTER END PLAY CHECK

Mount Torque Converter End Play Fixture (J-39195) and Dial Gauge (J-8001) on torque converter to check end play. Push down on fixture handle to bottom stator. Zero dial gauge. Pull up on fixture handle and check reading. End play should be 0-.024" (0-0.60 mm). (Scheme 1)

Scheme 1

Scheme 1: TORQUE CONVERTER END PLAY CHECK

TRANSMISSION SPECIFICATIONS

ApplicationIn. (mm)
Clutch Clearances
Direct Clutch.121-.186 (3.07-4.72)
Forward Clutch
Model ZFP.087-.150 (2.21-3.81)
Except Model ZFP.121-.186 (3.07-4.72)
Intermediate Clutch.040-.107 (1.02-2.72)
Overrun Clutch.033-.094 (.838-2.39)
4th Clutch.040-.100 (1.01-2.54)
End Play
Front Unit.004-.022 (.10-.56)
Output Carrier & Reaction Carrier
Pinion Gear.009-.024 (.023-.61)
Rear Unit.005-.025 (.13-.63)
Torque Converter0-.024 (0-.60)
Oil Pump Gears-To-Body Clearance.007-.0028 (.017-.071)

TRANSMISSION SPECIFICATIONS

TORQUE SPECIFICATIONS

ApplicationFt. Lbs. (N.m)
Center Support Bolt32 (43)
Connector Cooler Fitting Bolt29 (39)
Converter-To-Flexplate Bolt32 (43)
Extension Housing-To-Case Bolt25 (34)
Manual Shaft-To-Detent Lever Nut18 (24)
Oil Pan Bolt18 (24)
Parking Pawl Bracket-To-Case Bolt18 (24)
Pump Body-To-Case Bolt18 (24)
Pump Cover-To-Pump Body Bolt18 (24)
Rear Servo Cover-To-Case Bolt18 (24)
Rear Transmission Mount Bolt32 (43)
Rear Transmission Support Bracket Nut32 (43)
Transmission-To-Engine Bolt32 (43)
4th Clutch Bolt17 (23)
INCH Lbs. (N.m)
Accumulator Cover-To-Case Bolt98 (11)
Pressure Control Solenoid Bracket Bolt71 (8)
Lube Pipe Clamp Bolt98 (11)
Pipe Plug98 (11)
Speed Sensor Bolt98 (11)
Solenoid-To-Valve Body Bolt71 (8)
Valve Body-To-Case Bolt98 (11)

TORQUE SPECIFICATIONS