transmission

Transmission Oil Cooler

for 2017 Chevrolet Silverado 1500 5.3L V8 EcoTec3 L83 · RWD

Editorial review:Chris Hackleman — Master Technician · 20+ years · Jeff Moore — Master Lexus & Toyota Mechanic · 20+ years

Difficulty

Moderate

Time

2.0 h

Tools

Steps

🔧Does this apply to your car? Depending on trim and options — tow packages especially — your vehicle may have a separate auxiliary transmission cooler, or one integrated into the radiator side tank. Check which setup you have before planning this job: if it's integrated, cooler service happens with radiator replacement instead.

✓Expert-verified. Personally reviewed and approved by OLP's master technicians (Chris Hackleman & Jeff Moore — 20+ years each). Always follow the vehicle's factory service information and torque specs.

This procedure covers removal and replacement of the transmission oil cooler, which is integrated into the radiator assembly on 2014-2018 Silverado 1500 models with the 8L90 8-speed automatic transmission.

Warnings

⚠️Allow engine and transmission to cool completely before starting work. Hot coolant and transmission fluid can cause severe burns.

⚠The transmission oil cooler is integrated into the radiator on these models. Radiator replacement may be necessary if cooler is damaged.

⚠ATF is flammable. Keep away from hot surfaces and open flames.

ℹ️Transmission fluid capacity assumes complete system drain. Partial drain may require less fluid during refill.

Tools required

Drain pan (minimum 12 quart capacity)Essential

Socket set (metric)Essential

Line disconnect tool setEssential

Torque wrench (10-100 Nm range)Essential

Fluid transfer pump

Pliers (hose clamp type)Essential

Catch basin for coolantEssential

Jack and jack standsEssential

Shop rags

Parts

Transmission oil cooler lines × 2 — Use OEM specification or inspect for reuse
Transmission oil cooler line O-rings × 1 — Kit typically includes all seals
Transmission fluid × 1 — ACDelco Dexron VI
Engine coolant × 1 — ACDelco DEX-COOL Orange
Transmission oil cooler (integrated with radiator) × 1 — Use OEM specification

Fluids

ACDelco Dexron VI ATF — 11.5 qt
ACDelco DEX-COOL (Orange) — 18 qt

Preparation

Ensure engine and transmission are completely cool to the touch
Raise vehicle and secure on jack stands with front end elevated
Place large drain pan under radiator and transmission area
Remove engine splash shield and skid plates if equipped
Disconnect negative battery cable to prevent accidental fan activation

Procedure

1
Drain engine coolant
Open radiator drain petcock at bottom of radiator driver side and drain coolant into catch basin. Remove radiator cap to speed draining. Collect coolant for proper disposal or reuse if clean.
2
Remove upper radiator components
Remove upper radiator hose by loosening clamps. Disconnect overflow hose from radiator neck. Disconnect cooling fan electrical connectors at fan shroud. On models with auxiliary transmission cooler, note routing for reinstallation.
3
Disconnect transmission cooler lines from radiator
Locate transmission cooler lines at passenger side of radiator. Use line disconnect tool to release quick-connect fittings. Be prepared for residual ATF to drain (approximately 1-2 quarts). Cap open lines immediately to prevent contamination. Inspect lines for damage, cracks, or excessive wear.
4
Remove lower radiator hose
Loosen clamps on lower radiator hose and remove from radiator. Position drain pan to catch any remaining coolant from radiator and lower hose.
5
Remove radiator mounting hardware
Remove radiator support brackets at top of radiator. On models with A/C condenser, carefully separate condenser from radiator without disconnecting refrigerant lines. Support condenser with mechanics wire or bungee cord to prevent stress on lines.
6
Remove radiator assembly
Carefully lift radiator assembly upward and out of vehicle. Be cautious not to damage radiator fins on surrounding components. Inspect lower radiator mounts and rubber isolators for wear and replace if necessary. Verify integrated transmission cooler for leaks or damage.
7
Prepare new radiator with transmission cooler
Transfer any reusable components to new radiator assembly. Install new O-rings on transmission cooler line fittings using light coating of ATF for lubrication. Do not use petroleum-based lubricants on O-rings.
8
Install new radiator assembly
Carefully lower new radiator into position, seating lower mounts into rubber isolators. Reattach A/C condenser to radiator if separated. Install radiator support brackets and tighten mounting hardware securely.
9
Connect coolant hoses
Install lower radiator hose and tighten clamps securely. Install upper radiator hose and tighten clamps. Reconnect overflow hose to radiator neck. Ensure all hose clamps are positioned properly and not interfering with other components.
10
Connect transmission cooler lines
Clean transmission cooler line ends thoroughly. Install lines to radiator fittings, pushing firmly until quick-connect fittings click into place. Verify both lines are fully seated by attempting to pull them free with moderate force.
11
Refill cooling system
Fill radiator with ACDelco DEX-COOL coolant mixture (50/50 ratio). Fill to bottom of radiator neck. Fill coolant reservoir to COLD mark. Install radiator cap. Run engine with heater on maximum to burp air from system. Recheck coolant level after reaching operating temperature.
12
Refill transmission fluid
Remove transmission fill plug. Using fluid transfer pump, add ACDelco Dexron VI ATF through fill hole. Start with approximately 4-5 quarts initially. Start engine and shift through all gear ranges with brake applied. Check fluid level with engine running at operating temperature. Add fluid as needed to bring to proper level on dipstick. Most models require 5-7 quarts after cooler replacement, but verify with dipstick.
Torque spec
Fill Plug42 Nm (31 lb-ft)
13
Reinstall underbody components
Reinstall engine splash shield and skid plates. Reconnect negative battery cable. Lower vehicle from jack stands.

Reassembly

Double-check all hose clamps are tight and properly positioned
Verify transmission cooler lines are fully seated in quick-connect fittings
Ensure no tools or rags were left in engine compartment

Verification

Start engine and inspect for coolant leaks at radiator connections while engine warms up
Check for transmission fluid leaks at cooler line connections with engine running
Verify cooling fan operates correctly when engine reaches operating temperature
Test drive vehicle and monitor transmission temperature gauge if equipped, ensuring transmission operates in normal temperature range (175-200°F)
Recheck transmission fluid level after test drive with engine at operating temperature
Inspect ground under vehicle 24 hours after repair to verify no fluid leaks are present