Power steering is unreliable, surge/increase in steering power is very unpredictable. This vehicle has been to dealer 5 times for this problem. First time the dealer said alignment was problem, not so. Second time the dealer replaced the power steering gear box, this fixed problem for 4 months. Third time the dealer replaced power steering gear box, power steering pump and flushed lines, this fixed problem for 5 months. Fourth time the dealer replaced the evo sensor on steering column, this fix lasted 15 months. Fifth time the dealer stated that the evo sensor must be bad and will not replace under extended warrenty. After much investigation, I find that this is an ongoing problem specific to the 1997 Suburban with the electronic control on the power steering system. There have been in excess of 75 reports of this or similar steering related problems. NHTSA should investigate this prior to there being any fatalities.

- Knoxville, TN, USA

Vehicle steering would be very unstable and give way in turns at high and low speeds. Steering wheel was very loose and would be tight in a left turn and normal in right turns. Took it to the dealer and they said it was a bad steering gear box. I looked under the plastic shroud for the steering input shaft and the locking nut was loose. This steering problem seems to be a problem for other Suburban owners as well, I don't htink this gear box is the only cause and don't think I should have to pay $1000 dollars for a repair that is a manufacturer defect.

- Mountain Home, ID, USA

The failure is the variable ratio steering which is meant to be high effort\low ratio once the vehicle reaches a certain speed (10-20 mph ? )(or gear?) what occurs is the steering will intermittently go back and forth between the high effort -'cruising' ratio and the low speed -low effort -quick ratio at a speed above when it should remain in the high effort mode. I also owned a 97 K1500 Chevrolet pickup that also had a very similar problem. It however would stay one way or the other and not go between the 2 ratios which at least made it more predictable. It had a valve replaced under warrenty that fixed the problem at about 35,000.

- Benton City, WA, USA

Vehicle would wander while driving at 50 mph or more and oversteering would occur whenever changing lanes or making turns. Vehicle been in dealer shop on several occasions, and some repairs were made on gear box, but problem still occurs. Passing on information concerning NHTSA investigation.

- East North Port, NY, USA