Ok guys I had a friend do the the upper and lower ball joints and control arm on my 1999 for expedition XLT both sides...This was done about 2 months ago ...The other day I went to pull a stump out and was not able to engage the truck in to 4 wheel drive ... I hear no click when I turn the knob and the light dosnt come on in the dash window ... When I first start the truck the... 4x4 light comes on then go off ... Is there any thing I can look at before sending the truck to the shop Thanks Again Greg !!!!!