Remove and replace the transmission cooler lines that run between the transmission and the auxiliary transmission fluid cooler located in front of the radiator.

Warnings

Tools required

Parts

• Transmission cooler line set (inlet and outlet) × 1 — Use OEM specification or equivalent
• Transmission cooler line O-rings/seals × 4 — Included with line kit or order separately
• Mopar ATF+4 transmission fluid × 2 — Mopar 68218057AC or equivalent

Fluids

• Mopar ATF+4 — 2 qt

Preparation

1. Park vehicle on level ground and apply parking brake
2. Place wheel chocks behind rear wheels
3. Raise front of vehicle and secure on jack stands rated for vehicle weight (approximately 7,000+ lbs)
4. Remove driver side front wheel for improved access to transmission cooler lines
5. Place large drain pans under transmission and along the path of cooler lines
6. Clean the exterior of transmission cooler line connections at transmission and radiator with degreaser

Procedure

1. 1

   Access transmission cooler line connections
   From under the vehicle, locate the two transmission cooler lines exiting the driver side of the 68RFE transmission. The lines run forward along the frame rail to the auxiliary cooler mounted in front of the radiator. Note the routing and any clips or brackets securing the lines.
2. 2

   Disconnect cooler lines at transmission
   Using the appropriate quick disconnect tool or flare nut wrench, carefully disconnect both cooler lines from the transmission case fittings. The 2014 model uses push-to-connect style fittings at the transmission. Depress the locking tabs while pulling the lines straight out. Allow fluid to drain completely into the drain pan. Inspect the old O-rings on the transmission ports.
3. 3

   Remove line retaining brackets along frame
   Working from transmission toward radiator, remove all clips and brackets securing the cooler lines to the frame rail and body. There are typically 3-4 mounting points along the driver side frame rail. Note the exact position of each bracket for reinstallation.
4. 4

   Disconnect lines at auxiliary cooler
   At the front of the vehicle, locate where the cooler lines connect to the auxiliary transmission cooler (mounted in front of the radiator support). Use a flare nut wrench to loosen the threaded fittings. These are typically 14mm or 16mm fittings. Support the line while loosening to prevent twisting the cooler ports. Allow any remaining fluid to drain.
5. 5

   Remove old cooler lines
   Carefully extract the old cooler lines from the vehicle, navigating past frame rails, steering components, and other obstacles. Note the exact routing path, taking photos if necessary. Inspect the old lines for the location and cause of failure (corrosion, rubbing, impact damage).
6. 6

   Prepare new cooler lines
   Unpack new cooler lines and verify they match the old lines in length and fitting configuration. Install new O-rings on the push-connect ends that mate with the transmission. Lightly lubricate the O-rings with clean ATF+4 fluid. Ensure threaded fittings at the cooler end are clean and free of debris.
7. 7

   Route new lines to auxiliary cooler
   Beginning at the front of the vehicle, route the new cooler lines from the auxiliary cooler location back toward the transmission, following the exact path of the original lines. Ensure lines do not contact exhaust components, sharp edges, or moving parts. Loosely install any frame rail brackets but do not fully tighten yet.
8. 8

   Connect lines at auxiliary cooler
   Thread the cooler line fittings into the auxiliary cooler ports by hand first to ensure proper thread engagement. Tighten the fittings using a flare nut wrench to 30-35 Nm (22-26 lb-ft). Do not overtighten as this can damage the cooler ports. Ensure lines are not twisted or kinked.
9. 9

   Connect lines at transmission
   At the transmission end, verify new O-rings are properly seated on the line ends. Push each line straight into the transmission port until you hear and feel a positive click indicating the locking tabs have engaged. Firmly pull on each line to verify it is locked in place and will not pull free.
10. 10

    Secure all mounting brackets
    Work along the entire length of both cooler lines, ensuring all brackets and clips are properly installed and secured. Lines should be supported every 12-18 inches and must not contact any moving or hot components. Verify adequate clearance from steering linkage and suspension components through full range of motion.
11. 11

    Refill transmission fluid
    With vehicle still raised and level, remove the transmission dipstick. Using a long funnel, add approximately 2 quarts of Mopar ATF+4 to compensate for fluid lost during the line replacement. Start the engine and allow to idle. Shift through all gear positions, pausing 2-3 seconds in each position, then return to Park.
12. 12

    Check fluid level and inspect for leaks
    With engine idling in Park and transmission at operating temperature (approximately 180-200°F), check fluid level on dipstick. Add fluid as needed to bring level to the HOT range. While engine is running, carefully inspect all cooler line connections at transmission and auxiliary cooler for any signs of leakage. Check along entire length of lines for weeping or drips.

Reassembly

1. Reinstall driver side front wheel and torque lug nuts to factory specification (148 Nm / 109 lb-ft)
2. Lower vehicle from jack stands
3. Perform final fluid level check with vehicle on level ground and transmission at full operating temperature
4. Top off transmission fluid to proper level on dipstick HOT range as needed

Verification

• Start engine and let idle for 5 minutes, then shift through all gears while monitoring for proper engagement
• Perform a test drive including highway speeds to fully circulate fluid and verify proper transmission operation
• After test drive, re-inspect all cooler line connections for any signs of leakage
• Recheck transmission fluid level after test drive and adjust if necessary
• Verify no unusual noises, vibrations, or fluid spots under vehicle after completion

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