I have a 97 Tahoe with 246K miles on it. I treat the car well and it runs great. I'm in Richmond Va and during the winter we had 3 massive snow storms. So needless to say I was putting it in and out of 4wd. After the last snow I noticed a popping noise coming from under the engine. The noise happens when you shift into gear, brake, make a turn, go over a bump etc. It sounds like someone is knocking on the floorboard. You can also feel a slight bump on your feet when you hear the knock. I was thinking it was something to do with the suspension but the shop tells me it's a cracked transfer case, which is a $1700 repair. Being that the car is worth $1500 with the type of mileage on it this would effectively junk my car. I'm hesitant to believe these guys because from what I've read a broken transfer case is more of a grinding noise and it reduces how well you can drive it. It rides just fine (minus this noise) and the engine performs well. Does this sound to familiar to anybody? Do you think it's the transfer case of is there something else I can check? I don't want to get rid of my car. i don't want a car payment and I've been putting some cash into it the past 2 years to keep the engine primed. Let me know if anyone has any kind of experience with this. Your thoughts are much appreciated. Thank you.

 

Have you inspected the transfercase yourself? Have you looked at your u-joints? The u-joints tend to pop when put into gear, and tend to give a vibration at certain speeds. There is a problem GM trucks have that lets tension build up on the slip yoke (the connection of your transmission to the driveshaft). Look at the links below for the yoke problem...the first link will have a video on the 5th page to describe the knock.

http://www.gm-trucks.com/forums/inde...c=103620&st=60

http://www.truckmodcentral.com/forum...ead.php?t=2504

 

It is going to be hard to really help you because we can not hear it or see it. It could be the problem but might not be. Take it to another shop but do not tell them what the first shop said (you do not want to influence their diagnosis). If they say the same thing that is probably the problem. If it is the problem what about a used part?