Engine Mount - Front

This procedure covers the removal and replacement of the front engine mount on a 2007 Ram 3500 with the 5.9L Cummins diesel engine.

Warnings

Tools required

Parts

• Front engine mount assembly × 1 — OEM 52105546AA or equivalent
• Engine mount bolts (if corroded) × 1 — Use OEM specification

Preparation

1. Park vehicle on level ground and engage parking brake
2. Allow engine to cool completely if recently operated
3. Disconnect negative battery cable to prevent accidental starter engagement
4. Raise front of vehicle and support securely on jack stands at frame rails
5. Remove engine belly pan or skid plate if equipped
6. Apply penetrating oil to all mount bolts and allow to soak for 10-15 minutes

Procedure

1. 1

   Install engine support
   Position a floor jack with a wood block under the oil pan to support engine weight. Alternatively, install an engine support fixture from above. Raise jack or fixture until it just contacts the engine but does not lift it. The mount should still be bearing some weight.
2. 2

   Remove mount through-bolt
   Locate the through-bolt that passes horizontally through the engine mount bracket and mount body. This bolt connects the engine-side bracket to the frame-side mount. Remove the nut from the through-bolt, then drive the bolt out using a drift punch or dead-blow hammer. The bolt may be tight due to corrosion.
3. 3

   Support engine weight
   Carefully raise the engine approximately 1/2 inch using the floor jack or support fixture. This will relieve all tension on the front mount and create clearance for removal. Monitor engine position to ensure it does not contact hood, fan shroud, or other components.
4. 4

   Remove engine-side mount bracket bolts
   Locate the bolts attaching the mount bracket to the engine block front cover area. Verify the exact number and location of these bolts against factory service documentation for the 5.9L Cummins before removal. Remove these bolts completely and retain for reinstallation if in good condition.
5. 5

   Remove frame-side mount bolts
   Locate the bolts securing the mount body to the frame rail. Remove the bolts securing the mount body to the frame rail; verify the fastening method (captive nuts, weld nuts, or nut-and-bolt) against factory documentation for this platform. Remove these bolts and carefully lower the mount assembly away from the vehicle.
6. 6

   Inspect and clean mounting surfaces
   Inspect the engine block mounting surface and frame rail for cracks, damage, or excessive corrosion. Use a wire brush to clean all mounting surfaces, removing rust, old thread locker, and debris. Inspect all bolt threads and replace any damaged fasteners.
7. 7

   Position new mount to frame
   Position the new front engine mount onto the frame rail, aligning the bolt holes. Install the frame-side mount bolts finger-tight but do not torque yet. Ensure the mount is properly oriented with the engine-side bracket facing the correct direction.
8. 8

   Attach mount bracket to engine block
   While supporting the mount, carefully lower the engine using the jack or support fixture until the engine-side mounting holes align with the bracket. Install the engine-to-mount bracket bolts finger-tight. Verify alignment before proceeding.
9. 9

   Torque engine mount-to-block bolts
   Using a calibrated torque wrench of adequate range, torque the engine mount-to-block bolts to the factory-specified value (verify spec in service manual) in a crossing pattern if multiple bolts are present. Verify all bolts are properly seated before final torquing.
   Torque spec

   Engine Mount-to-Block Bolts65 Nm (48 lb-ft)
10. 10

    Torque frame-side mount bolts
    Torque the mount-to-frame bolts to specification. Ensure the mount is seated flush against the frame rail before final torquing.
    Torque spec

    Engine Mount-to-Frame Bolts75 Nm (55 lb-ft)
11. 11

    Install and torque through-bolt
    Install the through-bolt through the mount and bracket assembly. The bolt should pass freely through both components. Install the nut and torque to specification. This bolt centers the engine on the mount.
    Torque spec

    Through-Bolt85 Nm (63 lb-ft)
12. 12

    Remove engine support and verify
    Carefully lower and remove the floor jack or engine support fixture. Allow the engine to settle onto the new mount. Verify there is no binding and that the mount compresses slightly under engine weight. Check clearance around fan shroud, belts, and accessories.

Reassembly

1. Reinstall engine belly pan or skid plate if removed
2. Reconnect negative battery cable
3. Lower vehicle from jack stands

Verification

• Start engine and verify no abnormal vibration at idle or under load
• Visually inspect mount for proper compression and alignment while engine is running
• Test drive vehicle and verify smooth operation with no excessive engine movement during acceleration or deceleration
• Re-check all mount bolt torques after 50-100 miles of operation

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