• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

Bad Front Differential, 2500...


Full Member
Sep 15, 2002
Hello All,
I am a recent member of this here board and already Ive gotten a heap of useful information. Thanks!

I am the proud owner of a 2002 2500 series Avalanche. Ive had it in for front end problems 3 times now and Im wondering if anyone else has experienced difficulties with bad front hub engagement switches or vehicle speed sensors.

The first time I brought it to the dealer the differential would lock up after a 3 hour trip. Noticable in parking lots and slow tigh turns. Then one day while driving on the highway, the front left wheel locked up twice within a 5 second period for about 1/2 a second per time...definitely nerve racking and dangerous. I took it in and was told it was a defective front hub engagement switch. Seemed to do the trick but didnt have a long trip to test it on.

Second time, same story, long trip. About 2 hours into it, at about 75mph, the trans starts slipping totally, my ABS and brake lights stay on and my speedo starts going crazy. This happens for about 15 seconds then the trans catches again. Happened on and off for several miles. Brake and ABS lights are still on. I managed to limp it to a dealership where they find a bad Vehicle speed sensor. Switched it out and I was on the road in about 1 hour.

Driving home from said trip, drove for 2.5 hours flawlessly. As I got off the Hwy, it looked like the ramp was slippery so I switched into Auto 4WD. I came to a light. While stopped, the Check 4 wheel drive light comes on and I discover that the front wheels are totally locked up and it will not switch out of 4WD. Aye aye aye! I very rarely use Auto 4WD, its usually in 2WD.

The truck is now in the shop, has been for 5 days and will probably be there for at least 5 more. Chevy is going to replace the front differential and hopefully that will do the trick. They are saying that I had a slow leak in the differential and that caused the gears to seize up. The differential started giving me big problems immediately after it was in the shop for a differential service.

Anyone else have similar symptoms? Sorry this is so longwinded but wanted the info to be clear. Happy Avalanching!


Charter Member
Full Member
Feb 6, 2002
Welcome to the site...I will move this topic down a bit on the forum to the Questions,probs, and anwers section.....you won't have any problem finding the answer to your problem from our resident experts..good luck.... :B: