The contact owns a 2004 Jeep Grand Cherokee. The contact stated that while driving at various speeds, there was an abnormal sound coming from the front and rear underneath the vehicle. There was no warning light illuminated. The vehicle was taken to spitzer Chrysler Dodge Jeep Ram (13001 brookpark rd, cleveland, oh 44142 (216) 356-5749) where it was diagnosed and it was determined that the rear differential failed and needed to be replaced. The vehicle was repaired however, the failure recurred and worsened. The manufacturer was notified of the failure however, no further assistance was provided. The failure mileage was approximately 160,000.

- Middleburg Hights, OH, USA

I am writing because the front driveshaft differential assemble in my 2004 Jeep failed on January 4, 2008 after I put it into 4 wheel drive for the first time. I had it serviced the day before at a Goodyear store. On January 10 the repair company determined that the problem was caused because two new tires, purchased from and mounted by the same Goodyear service company, had been placed on the front and two of the existing tires with tread had been placed on the back per Goodyear's instructions. The two existing tires were lower in tread than the new tires by about an 1/2 to 1 inch and they said this caused the failure. I checked this with a local Jeep dealer and they said that this would happen and that the tire company should have known this. When I brought this to the attention of the tire company that mounted the tires on December 1 and also did the service, they said they did not know about this potential problem and that I should have purchased four tires from them. The tire people had given a price on four tires but said that there was enough tread on the two front tires to continue to use them for a few months. They decided to move two front tires to back and put the two new tires on the front. The mechanics said that the problem was caused by using the four wheel drive with these tires. There is nothing about his in the owner's manual; it says "proper operation of four wheel drive vehicles depends on tires of equal size, type and circumference on each wheel. Any difference will adversely affect shifting and cause damage to the transfer case." All tires meet this. Jeep/Chrysler said the car was out of warranty and even thought Jeep new about the problem; they said they were not responsible for fixing it or providing information to their customers about the problem. The Goodyear tire company is stevenson tire services in fremont. (510) 792-3363. I have all of the receipts, repair check list and owners manual.

- Fremont, CA, USA