engine

Serpentine Belt Tensioner

for 2014 Ram 2500 6.7L I6 Cummins Diesel · 4WD

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

Difficulty

Moderate

Time

1.6 h

Tools

Steps

✓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 the removal and replacement of the serpentine belt tensioner on a 2014 Ram 2500 with the 6.7L Cummins diesel engine.

Warnings

⚠️Allow engine to cool completely before beginning work. The Cummins diesel retains heat for extended periods.

⚠Keep track of belt routing before removal. Take a photo or reference the underhood belt routing diagram.

⚠The tensioner spring is under significant tension. Control the tensioner carefully when releasing or compressing.

Tools required

Socket set (metric)Essential

Torque wrenchEssential

Breaker bar or serpentine belt toolEssential

Ratchet with extensionsEssential

Shop light or work light

Drain pan (if coolant removal required)

Parts

Serpentine belt tensioner assembly × 1 — Use OEM specification
Serpentine belt (if worn or damaged) × 1 — Use OEM specification

Preparation

Park vehicle on level surface and engage parking brake
Allow engine to cool completely
Disconnect negative battery cable to prevent accidental starter engagement
Document or photograph serpentine belt routing pattern
Remove engine cover if equipped (typically pull up on front edge, then lift)

Procedure

1
Access the serpentine belt system
From the front of the vehicle, locate the serpentine belt system on the passenger side of the engine. On the 6.7L Cummins, the tensioner is positioned on the upper front of the engine block. Ensure you have clear access to the tensioner assembly and can reach the mounting bolt.
2
Release belt tension and remove belt
Using a breaker bar or serpentine belt tool, insert into the 1/2 inch square drive hole on the tensioner arm. Rotate the tensioner clockwise (towards the front of the vehicle) to release tension. Slip the belt off one pulley while holding tension released, then slowly release the tensioner. Remove the belt completely from all pulleys.
3
Inspect belt condition
Examine the serpentine belt for cracks, glazing, fraying, or missing ribs. Check for oil or coolant contamination. If the belt shows wear or damage, plan to replace it during reassembly. The belt should be replaced if you observe cracking on the rib side or significant glazing.
4
Remove tensioner mounting bolt
Locate the tensioner mounting bolt at the pivot point of the tensioner assembly. This is a single bolt that secures the tensioner to the engine block. Using the appropriate metric socket, remove the bolt completely. Support the tensioner with your other hand as you remove the final threads to prevent it from falling.
Torque spec
Belt Tensioner Bolt55 Nm (41 lb-ft)
5
Remove tensioner assembly
Pull the tensioner assembly away from the engine block. The tensioner should come off freely once the mounting bolt is removed. Inspect the mounting surface on the engine block for debris or damage. Clean the mounting surface with a clean rag if necessary.
6
Inspect tensioner and pulleys
Check the tensioner pulley for smooth rotation - it should spin freely without binding, roughness, or noise. Examine the tensioner arm for free movement and proper spring tension. Inspect all other belt-driven pulleys for wobble, noise, or roughness while you have access. Replace any components showing wear.
7
Install new tensioner assembly
Position the new tensioner assembly onto the engine block mounting point, aligning the bolt hole. Start the mounting bolt by hand to ensure proper thread engagement. Thread the bolt in several turns by hand before using tools to prevent cross-threading.
8
Torque tensioner mounting bolt
Using a torque wrench, tighten the tensioner mounting bolt to specification. Ensure the tensioner is properly seated against the engine block before final torque. Verify the tensioner arm moves freely through its full range of motion after installation.
Torque spec
Belt Tensioner Bolt55 Nm (41 lb-ft)
9
Route and install serpentine belt
Following the belt routing diagram (underhood label or your photo), route the new or existing belt around all pulleys except one. Start at the crankshaft pulley and work your way around. Leave the belt off one of the smooth idler pulleys or the alternator for final installation.
10
Tension belt onto final pulley
Using your breaker bar or belt tool, rotate the tensioner clockwise again to release tension. Route the belt onto the final pulley, ensuring the belt is properly seated in all pulley grooves. Slowly release the tensioner to apply proper tension to the belt. Verify the belt is centered on all pulleys.
11
Verify belt alignment and tension
Inspect the entire belt path to ensure the belt is seated correctly in all pulley grooves and is not twisted. The tensioner arm should be in the normal operating position (typically between the tension range marks if visible). Rotate the engine by hand one full revolution using the crankshaft bolt to verify smooth operation and proper belt tracking.

Reassembly

Reinstall engine cover if removed
Reconnect negative battery cable
Clear any diagnostic trouble codes if battery was disconnected

Verification

Start the engine and listen for any unusual squealing, chirping, or rattling from the belt system
Observe the belt while the engine idles to confirm it tracks properly on all pulleys without slipping or misalignment
Check that all accessories (alternator, air conditioning, power steering) operate normally
After 5-10 minutes of operation, shut off engine and recheck belt alignment and condition
Test drive the vehicle and verify no belt noise under various load conditions

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