Infiniti M35 Steering Problem (Tramlining)

I own a 2006 Infiniti M35 Sport (CPO with 27,000 miles) that is exhibiting very alarming steering characteristics. At highway speeds, braking to a stop, or riding over uneven roads the steering will pull very hard to the left or right (inconsistently) to the point where I must actively and constantly work to keep it centered (tire pressure is at spec).

I have heard that this is called “tramlining” and is not uncommon in performance vehicles. Some say that this issue can be reduced or eliminated by realignment, different brands of tires, or by getting a new steering rack. Any guidance?

Here Are A Couple Of Links:

Miracerros Link: (Note: I couldn’t get their link to Tire Rack to work.)
Take a look at Bumpsteer Or Tramlining?

Here’s Tire Rack: (Tramlining: Coping with the Ruts in the Road)

Another Tire Rack Link: (Alignment) Look at The Camber section (reference to negative camber, bumps, and tramlining.)

Most likely causes are worn tires or misaligned suspension. Take the car to an Infiniti or Nissan dealer or to a good, independent, foreign car shop and describe the symptoms.

The problem with tramlining of the M35s continues through 2009. This is not a characteristic that can be attributed to the performance nature of the car; it is a design defect of the M35s. Unfortunately, the problem cannot be resolved with change of tires–I have already tried two different brands to no avail. In the event, a conscientious mechanic at an Infiniti dealership in Tysons Corner, VA admitted that the problem is with the steering rack, but, as usual, Nissan is not prepared to admit it and issue a voluntary recall.

My guidance is for you (and all other drivers suffering from the same alarming condition) to complain to the National Highway Traffic Safety Administration and recommend a recall. If NHTSA receives enough complaints, it will probably force Nissan to issue a Technical Service Bulletin, if not an outright recall.

Thanks for the resources. I should have noted that my Bridgestone tires are in great shape and tire pressure is almost always at factory spec. Also, the Infiniti dealer looked into my steering complaint and said that the steering rack, suspension, and alignment all checked out fine. The technican and service manager simply said that the M35 steering characteristics are typical for that kind of car (which is garbage because the G35/37 doesn’t generate these kinds of complaints).

The Tire Rack articles were helpful - particularly around camber and the difference between bumpsteer and tramlining. What I’m not clear on is if the design of the Inifiniti’s steering/alignment is faulty then how will a new steering rack (which I presume follows the original design) will help resolve the situation.

I have filed a complaint with the NHTSA as have dozens of others but I wonder how many have to file before a technical bulletin/recall actually happens. Guess I should have gone with the Acrua RL …