GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hello, my name is ***** ***** I will do all I can to help. If you raise the rear end up with a floor jack, and both rear wheels are hoisted off the ground, See if you hear any abnormal noise or grinding coming from the rear axle when you put it in N or D. keep your foot on the brake firmly and make sure the rear wheels aren't spinning before putting it in D or R. I believe the spider gears are damaged, I've seen it before and it will lock up one side in reverse and one side in drive. See if you hear any abnormal noises or grinding from the rear axle when you check it with the wheels off the ground. let me know what you find there and if you have any further questions.