2012-2013 Infiniti M35h Steering Rack: A Guide to the Hybrid-Specific System

Understanding the 2012-2013 M35h Electric Power Steering Rack

The steering rack in the 2012-2013 Infiniti M35h is a critical component that translates your steering wheel inputs into the turning of the front wheels. These models are equipped with a vehicle-speed-sensitive electric power steering (EPS) system. This means there is no hydraulic pump or power steering fluid. Instead, an electric motor provides the assistance, making the car easier to handle. This system is exclusive to the M35 Hybrid and is not compatible with the standard gasoline M37 or M56 models, which use a different setup.

Symptoms of a Failing M35h Steering Rack

Because this is an electric system, failure symptoms can be both mechanical and electrical. Here are the most common signs that your M35h steering rack may be failing:

• Heavy or Stiff Steering: The most common symptom is a sudden or intermittent increase in the effort required to turn the steering wheel. This indicates the electric assist motor is failing or not receiving the correct signals. It may be most noticeable at low speeds or when parking.
• Steering Assist Fails Intermittently: The power assist may cut out and then return unexpectedly. This can be caused by a faulty torque sensor, a problem with the control module, or a wiring issue.
• Clunking or Knocking Noises: A clunking or thudding sound when turning the wheel or going over bumps can indicate worn internal gears or loose mounting points in the rack itself.
• Power Steering Warning Light: An illuminated power steering warning light on the dashboard (often an icon of a steering wheel with an exclamation mark) signals that the onboard computer has detected a fault in the EPS system.
• Steering Wheel Vibration: Excessive vibration felt through the steering wheel, especially when turning, can be a sign of a problem with the electric motor or gears within the rack.

Known Issues, Recalls, and Technical Service Bulletins (TSBs)

While there are no specific recalls for the steering rack itself on the 2012-2013 M35h, there are related recalls and TSBs for these vehicles. For example, recall NHTSA 16V-527 was issued because a hybrid powertrain cooling system malfunction could lead to the engine shutting off while driving. While the steering system would remain operational, the loss of engine power could increase crash risk. Dealers were instructed to reprogram the control modules to prevent this. No widespread TSBs directly addressing steering rack failure were found in research, suggesting failures are typically due to normal wear and tear rather than a specific design defect.

Buying a Used 2012-2013 M35h Steering Rack: What to Look For

A recycled OEM steering rack can be a cost-effective and reliable alternative to an expensive new part. Here’s what to focus on when buying used.

Verify the Part Number: The Hybrid-Only Rule

This is the most important step. The M35h uses a unique electric rack. You must match the OEM part number to ensure compatibility. Verified part numbers for this application include:

• 49001-1MG0A
• 49001-1MG1A
• 49001-3WG0A (replaces previous numbers)
• 49200-1MG0A
• 49200-1MG1A
• 49200-3WG0A

The '49001' series generally refers to the rack and pinion assembly with inner tie rods, while the '49200' series may refer to a different assembly configuration. Always confirm with the seller which components are included.

Physical Inspection Checklist

Even without powering it on, you can spot red flags on a used rack:

• Check the Electrical Connectors: Look for any signs of corrosion, bent pins, or damage to the wiring harness. A damaged connector can cause intermittent failures.
• Inspect the Bellows Boots: The rubber boots at each end of the rack protect the inner tie rods. Ensure they are not torn, cracked, or leaking grease. Damaged boots allow contaminants in, which will destroy the inner joints.
• Examine the Housing: Look for any cracks, dents, or signs of heavy impact on the main aluminum housing of the rack and electric motor.
• Check the Inner Tie Rods: With the rack on a flat surface, try to move the inner tie rods up and down. There should be no excessive play or clunking.

Mileage and Wear

Steering racks are durable components, but the electronics can fail over time. Most steering systems are designed to last well over 100,000 miles. When buying used, a part from a lower-mileage vehicle is always preferable, as it has experienced less electrical and mechanical stress.

Replacement Considerations

Related Parts to Replace

It is highly recommended to replace the outer tie rod ends when installing a new or used steering rack. They are a common wear item and are inexpensive. A wheel alignment is mandatory after replacement, so replacing the tie rod ends at the same time saves you from paying for a second alignment down the road.

Cost Comparison: New, Used, and Remanufactured

The electric steering rack for the M35h is a specialized and expensive component. This makes a quality used OEM part a very attractive option.

Note: Prices are estimates and can vary based on supplier, location, and part condition. Labor costs do not include the mandatory wheel alignment.

Frequently Asked Questions (FAQ)