Service bulletin LI27.60-P-079969
A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.
| Type | Service bulletin |
|---|---|
| NHTSA id | 11025536 |
| Published by NHTSA | 2025-11-14 |
| Manufacturer's number | LI27.60-P-079969 |
| Manufacturer's date | 2025-11-05 |
| NHTSA component | POWER TRAIN |
NHTSA's summary
Complaint Harsh 2-1 downshifts when coming to a stop with ECO start-stop function turned OFF. Note: When ECO start-stop is active, the engine is shut off before the 2-1 shift and the complaint will not occur. Cause Software application when engine is running. Remedy Short-term remedy: Perform IPR and follow the instruction to perform standstill adaptations. Long-term Solution: Aftersales software is currently in development. NOTE: The information contained in this document is intended for use by trained, professional technicians with the knowledge to properly and safely perform diagnosis and repairs on Mercedes-Benz vehicles, using Mercedes-Benz approved tools and equipment. It informs service technicians about conditions that could occur in certain vehicles and provides information that could assist in proper vehicle diagnosis, service, or repair. It does not indicate that a defect is present in any vehicle referenced in this document nor does it imply warranty coverage. DO NOT assume that a symptom or condition, or a described cause of a symptom or condition, affects any particular vehicle or groups of vehicles, or that a described repair applies to any particular vehicle or groups of vehicles. There can be multiple causes resulting in the same or similar symptoms or conditions described in this document, and trained professional service technicians must use their diagnostic skills to make evaluations on a case-by-case basis. The information contained in this document does not guarantee warranty coverage nor does it extend the vehicle’s warranty in any way.
The document
The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.
Components
Transmission and driveline
| MERCEDES-BENZ AMG C43 | 2023 to 2024 |
|---|---|
| MERCEDES-BENZ AMG C43 4MATIC | 2023 to 2025 |
| MERCEDES-BENZ AMG C63 S E | 2024 |
| MERCEDES-BENZ AMG C63 S E 4MATIC+ | 2024 to 2025 |
| MERCEDES-BENZ AMG E 53 4MATIC+ WAGON | 2025 |
| MERCEDES-BENZ AMG GLC63 S E | 2025 |
| MERCEDES-BENZ AMG GLC63 S E 4MATIC+ COUPE | 2025 |
| MERCEDES-BENZ C 300 | 2022 to 2025 |
| MERCEDES-BENZ C 300 4MATIC | 2023 to 2025 |
| MERCEDES-BENZ CLE 300 | 2024 (the catalog's model; the bulletin names a series or trim of it) |
| MERCEDES-BENZ CLE 450 | 2024 (the catalog's model; the bulletin names a series or trim of it) |
| MERCEDES-BENZ E 350 | 2025 |
| MERCEDES-BENZ E 350 4MATIC | 2025 |
| MERCEDES-BENZ E 450 | 2024 |
| MERCEDES-BENZ E 450 4MATIC | 2025 |
| MERCEDES-BENZ E 450 4MATIC ALL-TERRAIN | 2025 |
| MERCEDES-BENZ GLC 300 | 2023 to 2026 |
| MERCEDES-BENZ GLC 300 4MATIC | 2023 to 2026 |
| MERCEDES-BENZ GLC 300 4MATIC COUPE | 2024 to 2026 |
| MERCEDES-BENZ GLC 300 COUPE | 2024 |
| MERCEDES-BENZ GLC 350 E 4MATIC | 2025 |
Listing a model year does not mean every vehicle of it is concerned: the document says which.
| LI35.31-P-080353 | 2026-10-02. Service bulletin. Complaint Whining / humming noises (described as foghorn‑like) from the drivetrain in the rear axle area during cornering. (figure 1) On the above‑mentioned vehicles with a mileage up to 15,000 km (about 9,300 mi), noises can occur from the rear axle differential. Cause Drivetrain resonance caused by the gear mesh of the ring and pinion in the rear axle differential in combination with installed damper elements on the axle shafts. Remedy For precise noise analysis and localization, use the chassis ear/NVH kit and the following driving procedure: 1. Drive the vehicle in a tight circle with the steering at full lock in both clockwise and counter clockwise directions. ‑ Vary engine load during the maneuvers If a foghorn‑like noise occurs comparable to the reference video, the vehicle exhibits the condition If the noise is present: 1. Add 15 ml of additive (Friction Modifier) into the rear axle differential via the filler plug IMPORTANT NOTE: Do NOT use Friction Modifier in vehicles equipped with an electronically controlled locking differential (Code 467). 2. Tighten the filler plug 3. Drive the vehicle until the rear axle differential reaches operating temperature Note: Proper activation of the additive requires elevated oil temperatures After the test drive to operating temperature, evaluate the noise when the rear axle is cold and when warm. If the noise is no longer present: The issue is resolved and the vehicle can be released. If there is noticeable improvement: The vehicle can be released with the explanation that the noise will gradually disappear over an extended driving distance. If the noise is still present and remains unchanged: Replace the rear axle differential. |
|---|---|
| LI33.30-P-080490 | 2026-08-05. Service bulletin. Complaint Leakage/oil leakage at drive pinion sealing ring (input shaft) (Figures 1-2) Minor leakage/slight seepage at coupling flange nut at drive pinion (Figures 3-4) Cause Damage to sealing ring during production process or insufficient use of lubricating paste during assembly of collar nut on coupling flange Remedy If any of the above-mentioned customer complaints are present, or if oil leakage or seepage is found at the front axle differential during a workshop visit, the following steps must be performed: If oil leakage is found at drive pinion sealing ring (input shaft): • Remove coupling flange from differential, AR33.30-P-0550WT • Replace drive pinion sealing ring • New collar nut (for coupling flange), part number A 221 353 03 72, on contact surface and coat the 1st thread (from contact side to coupling flange) with lubricating paste (Figures 5-6) • Install coupling flange. If oil leakage or slight seepage is found at coupling flange nut to drive pinion: • Remove coupling flange from differential, AR33.30-P-0550WT • Clean threads on input shaft • new collar nut (for coupling flange), part number A 221 353 03 72, on contact surface and coat the 1st thread (from contact side to coupling flange) with lubricating paste (Figures 5-6) • Install coupling flange. |
| LI35.30-P-058566 | 2026-07-14. Service bulletin. Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The noise is heard once in each instance when changing direction of travel. Note: Sound file in attachment Cause If the complaint is eliminated by experimentally loosening the outboard collar nut (by 1 turn), the problem is due to cracking of the microweld between the wheel bearing inner race and the joint housing of the side shaft. Note: The collar nut must always be replaced after being loosened. See also LI33.20-P-078406 Remedy Coat contact surface of side shaft with wheel bearing with Molykote paint. To do this, proceed as follows: 1. Remove side shafts 2. Clean contact surface A (see image file in attachment "Outer joint housing before") before coating with Molykote, using "spirit" (free of dust and grease) 3. Coat contact surface A (see image file in attachment "Outer joint housing after") with Molykote and leave to dry for "one hour" in removed condition 4. Reinstall side shafts Note: Before using the antifriction coating (Molykote), stir it or shake it thoroughly for (at least 1 minute). |
| LI33.30-P-056665 | 2025-11-20. Service bulletin. Complaint Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The clunk is heard once when changing from forward to reverse (and vice versa). Note: Sound file in attachment Cause If the complaint is eliminated by experimentally loosening the outboard collar nut (by 1 turn), the problem is due to micromovement in the connection between the wheel bearing inner race and the joint housing of the side shaft. Note: The collar nut must always be replaced after being loosened and must be tightened to the specified torque. Remedy Coat contact surface of side shaft with wheel bearing with Molykote paint. To do this, proceed as follows: 1. Remove outboard side shafts (extract outer joint gearing from wheel hub) 2. Clean contact surface A (see picture file in attachment "Outer joint housing before") before coating with Molykote, using "spirit" (free of dust and grease) 3. Coat contact surface A (see image file in attachment "Outer joint housing after") using Molykote and leave to dry for one hour in removed condition 4. Reinstall side shafts Note: Before using the antifriction coating (Molykote), stir or shake it well (for at least 1 minute). |
| LI27.60-P-079968 | 2025-11-07. Service bulletin. Complaint A harsh 5-4 downshift can be felt during deceleration while braking or coasting. It may be mistaken for a hard brake engagement Cause Poor learning of brake B06 adaptation values over time. Remedy Short-term remedy: 1. Perform IPR and follow the instructions. 2. Perform resetting of deceleration values (VGS > Special Procedures > Special procedure > Resetting learned values Deceleration mode) 3. Perform standard adaptation 4. Reevaluate the concern and release vehicle if no longer present Note: ALL steps (resetting learned values and standard adaptation) must be completed to fully resolve the complaint. Long-term measure: Aftersales software is currently in development. |
| LI33.30-P-056665 | 2025-06-03. Service bulletin. Complaint Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The clunk is heard once when changing from forward to reverse (and vice versa). Note: Sound file in attachment Cause If the complaint is eliminated by experimentally loosening the outboard collar nut (by 1 turn), the problem is due to micromovement in the connection between the wheel bearing inner race and the joint housing of the side shaft. Note: The collar nut must always be replaced after being loosened and must be tightened to the specified torque. Remedy Coat contact surface of side shaft with wheel bearing with Molykote paint. To do this, proceed as follows: 1. Remove outboard side shafts (extract outer joint gearing from wheel hub) 2. Clean contact surface A (see image file in attachment "Outer joint housing before") before coating with Molykote, using "spirit" (free of dust and grease) 3. Coat contact surface A (see image file in attachment "Outer joint housing after") using Molykote and leave to dry for one hour in removed condition 4. Reinstall side shafts |
| LI33.30-P-056665 | 2025-01-31. Service bulletin. Complaint Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The clunk is heard once when changing from forward to reverse (and vice versa). Cause If the complaint is eliminated by experimentally loosening the outboard collar nut (by 1 turn), the problem is due to micromovement in the connection between the wheel bearing inner race and the joint housing of the side shaft. Note: The collar nut must always be replaced after being loosened and must be tightened to the specified torque. Remedy Coat contact surface of side shaft with wheel bearing with Molykote paint. To do this, proceed as follows: 1. Remove outboard side shafts (extract outer joint gearing from wheel hub) 2. Clean contact surface A (see image file in attachment "Outer joint housing before") before coating with Molykote, using "spirit" (free of dust and grease) 3. Coat contact surface A (see image file in attachment "Outer joint housing after") using Molykote and leave to dry for one hour in removed condition 4. Reinstall side shafts Note: Before using the antifriction coating (Molykote), stir it or shake it thoroughly for (at least 1 minute). |