Tenneco Automotive recall 20E091

Affected vehicles (3)

Component / system

Defect

Ohlins USA, Inc (Ohlins) is recalling certain Front Struts, part number POS 5N20. These struts were sold as part of Ohlins strut kits part number POZ MN02, intended for installation on 1999-2005 Porsche 911 Carrera 4 and 4S (generation 996), and 2001-2006 Porsche 911 Turbo / Turbo S (generation 996) and kit part number POZ MN05, intended for installation on 2005-2012 Porsche 911 Carrera 4 and 4S (generation 997), and 2006-2013 Porsche 911 Turbo / Turbo S (generation 997). The pin of the strut may experience excessive stress during maximum steering, possibly resulting breakage of the pin.

Risk / consequence

If the pin fails, it will cause separation of the strut from the vehicle, affecting vehicle control and increasing the risk of a crash.

Remedy

Ohlins will notify owners, and dealers will request the return of all unsold kits containing the subject part from dealer/distributor inventory for a full refund. All owners who purchased one of the kits (POZ MN02 or POZ MN05) will receive replacement front struts (POS 5N20 or POS 5N21 - These parts are interchangeable), along with new top mount interface solutions, free of charge. The recall began December 22, 2020. Owners may contact Ohlins customer service at 1-800-336-9029.

Chronology of events

1. Jun 24, 2020

   6/24/20: Initial report regarding vehicle with two broken front struts communicated to Ohlins Sweden (no accident or property damage). Initial information indicates incorrect installation.

2. Jun 24, 2020

   6/24/20: Ohlins Sweden R&D team initiates engineering investigation. 6/26 – 7/12/20: Analysis of possible root cause started (Ishikawa), including mounting errors, changed design of OEM parts, problem with worn OEM top mounts, over-tightening of top pin, etc.

3. Jul 14, 2020

   7/14/20: As a precaution, Ohlins Sweden suspends shipments pending completion of engineering analysis.

4. Jul 21, 2020

   7/21/20: Second report of broken driver-side top pin on 997 Turbo received (no accidents or damage).

5. Aug 11, 2020

   8/11/20: Ohlins Engineering conducts first mounting test on 996 vehicle in Sweden. Testing continues in August and September to determine if mounting error can occur, if over-tightening of the top pin can cause the problem, if worn OEM top mount can cause excessive forces into strut or top pin, if parts in OEM top mount and interface to Öhlins strut can rotate causing excessive forces. Some potential causes ruled out, but difficult to draw conclusions for root cause until failed parts could be analyzed.

6. Sep 17, 2020

   9/17/20: Failed part received by Ohlins Sweden. 10/20 – 11/20: Testing performed with 2nd vehicle (997 Turbo) to identify high stress.

7. Nov 4, 2020

   11/4/20: Material analysis confirms materials are to specification; no manufacturing defect identified.

8. Nov 12, 2020

   11/12/20: Complete FEA model to calculate bending torque from top mount and correlate measurements on vehicle. 11/12 – 12/4/20: Validation of potential root cause.

9. Nov 17, 2020

   11/17/20: Engineering team preliminarily concludes interface between strut and OEM top mount is likely root cause.

10. Nov 30, 2020

    11/30/20: Findings of investigation reviewed; decision to escalate issue to Tenneco Global Warranty Committee (GWC).

11. Dec 4, 2020

    12/4/20: GWC reviews results of investigation and decides to initiate this safety recall. Ohlins USA is not aware of any accidents or injuries related to this issue.

Notification schedule

Dealer notification

DEC 21, 2020 - DEC 24, 2020

Owner notification

JAN 04, 2021 - JAN 08, 2021