What do you mean it doesnt work? The t-case shifter on my truck has seized up before. It would go into 4 hi, but the shifter would not push down to go into N or 4 low. If this is the case, lube the linkage underneath the cab and try to work it back and forth. The shifter had to be removed to get it freed up on my truck. Make sure to lube these linkages frequently, especially if you do not use 4 low a lot. But this depends on whether or not you have a manual shifter, like the last poster said. Hope this helps.