I have a 97 all wheel drive Ford Exloder and if the vehicle is moving (in gear or nuetral) there is a hard knock coming from the front differential. I thought it was a trany problem but I lifted the front and blocked the rear wheels off and could see thats where the knock was coming from when it idled in drive. When I blocked the front and lifted the back the rear wheels spun with no knock. What am I facing? A completely new differential.. having it rebuilt..? Is this an easy/cheap fix?
Thanks for reading and answering.