Complaint Rattling noise from underneath the vehicle

Bulletin number

LI4910-N-060969

Component

Engine

Summary

Complaint Rattling noise from underneath the vehicle. Cause One or more of the following conditions may be present: 1. The exhaust bracket from the DPF to the transmission is cracked or broken. • See Pic. 1 for an example of a broken bracket. 2. Transmission bell housing cracked or broken at the exhaust mounting area. • See Pic. 2 for an example of bell housing damage. 3. Exhaust bracket from DPF to engine (cylinder crankcase) cracked or broken. • See EPC OM651 #217 for bracket location. 4. Diesel Particulate Filter (DPF) pipe cracked at a weld joint. • Cracking may be present at bracket welds or along the DPF housing seams. • This can cause rattling noises and secondary exhaust bracket stress. • Perform a visual inspection of the DPF pipe and weld joints. Remedy Inspect all related components and repair or replace as required. Inspection and Repair 1. Inspect the exhaust bracket from the DPF to the transmission. • Check the bracket for cracks or complete separation. • See Pic. 1 for a failed example. • See EPC OM651 #550 and Pic. 3 for bracket location. • If damaged, replace the bracket. • See Pic. 4, Pic. 5, and Pic. 6 for the updated bracket design and identification. 2. Inspect the transmission bell housing. • Inspect the bell housing at the exhaust mounting point for cracks or structural damage. • See Pic. 2 for an example of bell housing damage. • Replace the transmission if damage is confirmed. 3. Inspect the exhaust bracket from the DPF to the engine (cylinder crankcase). • Inspect the bracket for cracks or broken mounting points. • See EPC OM651 #217 for bracket location. • Replace the bracket if damaged. 4. Inspect the DPF pipe. • Inspect the DPF for cracks at weld joints, especially near mounting points. • If cracking is found, replace per current aftertreatment guidelines. Correct positioning and tightening of the exhaust system are critical to prevent repeat failures. Positioning the Exhaust System 1. Position and align the exhaust system before tightening. • Support and fit the exhaust system in its installed position. • Push the exhaust system forward. • Install the DPF‑to‑transmission bracket and lightly tighten the mounting bolt. • Install the engine mount and V‑mount bolts by hand, approximately two turns. • See “Positioning of the exhaust system” image. Tightening Sequence 1. Tighten the exhaust system in the correct sequence. • Tighten engine mounting bolts to 25 Nm. • Tighten V‑mount bolts to 25 Nm. • Tighten exhaust bracket bolts to 15 Nm. • See “Tightening sequence of the exhaust system” image. 2. Verify mounting bolt locations. • Confirm correct mounting screw positions at the transmission bracket. • See Pic. 7 and Pic. 8 for mounting screw locations.

Owners of these vehicles have filed 94 complaints in the engine category.