This procedure covers removal and replacement of the flexplate on a 2014-2018 Chevrolet Silverado 1500 with the 5.3L V8 L83 engine and automatic transmission, requiring transmission removal for access.

Warnings

Tools required

Parts

• Flexplate × 1 — GM 12643713 or equivalent
• Rear main seal × 1 — Replace if showing signs of leakage
• Transmission fluid pan gasket × 1 — Use OEM specification
• Transmission filter × 1 — Replace during service

Fluids

• ACDelco Dexron VI ATF — 11.5 qt

Preparation

1. Disconnect negative battery cable and secure away from battery post
2. Raise vehicle on lift or safely support on jack stands at frame contact points with front slightly higher than rear
3. Remove skid plates or underbody shields if equipped
4. Place drain pan under transmission and drain transmission fluid from pan
5. Remove driveshaft and mark yoke-to-pinion flange orientation for reassembly
6. Disconnect transmission cooler lines at transmission using line wrenches
7. Disconnect electrical connectors at transmission (range sensor, solenoid harness, speed sensor)
8. Remove starter motor assembly and secure out of the way
9. Support engine from above using engine support bar or hoist with load leveler

Procedure

1. 1

   Remove transmission crossmember
   Position transmission jack under transmission pan with a block of wood to distribute load. Raise jack until it just contacts transmission. Remove transmission crossmember mounting bolts and lower crossmember away from vehicle. Verify transmission is secure on jack.
   Torque spec

   Mounting Bolts60 Nm (44 lb-ft)
2. 2

   Disconnect shift linkage and wiring harness
   Disconnect shift cable from transmission lever and remove cable bracket. Disconnect transmission harness from all sensors and solenoids. Remove any remaining electrical connector bolts securing harness brackets to transmission case.
   Torque spec

   Electrical Connector Bolts8 Nm (6 lb-ft)
3. 3

   Access torque converter bolts
   Remove transmission dust cover or flexplate inspection cover from bellhousing. Mark position of torque converter to flexplate with paint pen for reassembly reference. Rotate crankshaft using a socket on the harmonic balancer bolt to access each torque converter bolt through the inspection opening.
   ℹ️There are typically 6 torque converter bolts spaced evenly around the converter. Ensure all are removed before attempting transmission removal.
   Torque spec

   Cover Bolts20 Nm (15 lb-ft)
4. 4

   Remove torque converter bolts
   Using a socket through the inspection opening, remove all six torque converter-to-flexplate bolts while rotating crankshaft to access each bolt. Keep these bolts separate as they may differ from flexplate bolts. Push torque converter back toward transmission to ensure it disengages from flexplate.
   Torque spec

   Torque Converter Bolts50 Nm (37 lb-ft)
5. 5

   Remove transmission-to-engine bolts
   Remove all transmission bellhousing-to-engine block bolts. Note locations of any bolts that secure harness brackets or ground straps. Support transmission firmly on jack and verify all bolts are removed before proceeding.
   ⚠️Ensure transmission jack is secure and positioned correctly. Transmission will shift rearward when separated from engine block.
   Torque spec

   Transmission-to-Engine Bolts55 Nm (41 lb-ft)
6. 6

   Separate and lower transmission
   Carefully pull transmission straight back away from engine, ensuring torque converter remains fully seated in transmission pump. Once input shaft clears bellhousing, slightly lower transmission angle and continue moving rearward. Lower transmission completely and remove from under vehicle. Plug transmission to prevent contamination.
   ⚠Keep torque converter tilted upward to prevent it from sliding out of transmission. If converter falls out, transmission pump may be damaged during reinstallation.
7. 7

   Lock crankshaft and mark flexplate orientation
   Install flywheel holding tool or lock starter ring gear to prevent crankshaft rotation. Mark flexplate orientation to crankshaft using paint pen on both flexplate and crankshaft flange. Note the offset weight positioning on flexplate - this must be reinstalled in the same orientation.
   ⚠Flexplate is NOT symmetrical. Installing it backwards will cause severe vibration and potential engine damage. Mark orientation clearly.
8. 8

   Remove flexplate bolts
   Using a breaker bar and socket, loosen all flexplate-to-crankshaft bolts in a crisscross pattern to prevent warping. Remove all bolts completely and set aside (these bolts should be replaced or inspected for thread damage). Remove flexplate from crankshaft, noting the orientation and any spacers or shims.
   Torque spec

   Flexplate Bolts85 Nm (63 lb-ft)
9. 9

   Inspect components and clean mating surfaces
   Thoroughly inspect old flexplate for cracks, especially around bolt holes and converter mounting pads. Check crankshaft flange for damage or wear. Clean crankshaft flange and engine block rear surface with brake cleaner and lint-free cloth. Inspect rear main seal for leakage; replace if seeping oil. Check dowel pins in crankshaft are present and not damaged.
10. 10

    Install new flexplate
    Position new flexplate onto crankshaft flange aligning the dowel pins and matching the orientation marks made during removal. Ensure offset weight and any balance marks face the correct direction (typically weight toward transmission). Install NEW flexplate bolts with medium-strength thread locker applied to threads.
    ⚠Verify flexplate part number matches engine application. L83 engines may have specific flexplate requirements based on transmission type.
11. 11

    Torque flexplate bolts to specification
    With crankshaft still locked, tighten flexplate bolts following the GM specified sequence (typically star pattern starting at 12 o'clock position). Torque all bolts to 85 Nm (63 lb-ft) in multiple progressive steps: first to 30 Nm, then 60 Nm, then final torque of 85 Nm. Verify each bolt is properly torqued.
    ⚠Improper torque sequence can crack flexplate. Follow GM service manual tightening sequence exactly.
    Torque spec

    Flexplate Bolts85 Nm (63 lb-ft)
12. 12

    Reinstall transmission
    Verify torque converter is fully seated in transmission pump (should be recessed approximately 1/2 inch from bellhousing face). Apply thin film of high-temp grease to torque converter hub. Raise transmission into position, align with engine block dowels, and carefully slide forward ensuring converter hub engages with crankshaft and flexplate. Do not force - if resistance is felt, lower and realign.
13. 13

    Install transmission mounting bolts
    Install all transmission-to-engine bolts and tighten following GM specified sequence. Torque to 55 Nm (41 lb-ft). Ensure transmission is fully seated against engine block before final torquing. Reinstall any ground straps or harness brackets removed earlier.
    Torque spec

    Transmission-to-Engine Bolts55 Nm (41 lb-ft)
14. 14

    Install torque converter bolts
    Rotate crankshaft to align torque converter bolt holes with flexplate holes, matching orientation marks made during disassembly. Apply medium-strength thread locker to torque converter bolt threads. Install all six bolts through inspection opening while rotating crankshaft. Torque to 50 Nm (37 lb-ft) following specified sequence.
    ℹ️Verify torque converter is fully engaged before installing bolts. Gap between converter and flexplate should be minimal and consistent.
    Torque spec

    Torque Converter Bolts50 Nm (37 lb-ft)
15. 15

    Complete transmission installation
    Install flexplate inspection cover and torque cover bolts to 20 Nm (15 lb-ft). Install transmission crossmember and torque mounting bolts to 60 Nm (44 lb-ft). Remove transmission jack. Reconnect shift linkage, electrical connectors (torque connector bolts to 8 Nm), cooler lines, and driveshaft matching original orientation marks. Install starter motor. Refill transmission with 11.5 quarts ACDelco Dexron VI ATF through dipstick tube.
    Torque spec

    Cover Bolts20 Nm (15 lb-ft)

    Mounting Bolts60 Nm (44 lb-ft)

    Electrical Connector Bolts8 Nm (6 lb-ft)

Reassembly

1. Reinstall all underbody shields and skid plates removed during preparation
2. Reconnect negative battery cable
3. Double-check all fluid levels including transmission fluid with engine running in Park
4. Verify all electrical connectors are fully seated and locked
5. Check for any fluid leaks around rear main seal and transmission cooler lines

Verification

• Start engine and verify no abnormal noises from bellhousing area
• With engine at operating temperature, cycle transmission through all gear ranges and verify smooth engagement
• Test drive vehicle and verify no vibration, unusual sounds, or transmission slippage
• Recheck transmission fluid level with engine running at operating temperature in Park on level ground
• Inspect under vehicle for any fluid leaks at transmission, rear main seal, and cooler line connections
• Verify no check engine lights or transmission fault codes are present using scan tool

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