knocking drivetrain sound???

[MUDDING B-3000]

ok well when my truck sits over night an i drive it the next day my front end has a knocking sound but it happens when im driving slow like 10-20 kmh, then after about 5 min it goes away an doesnt start again till then nxt time my truck sits over night?? my truck is a 94 b3000 4x4 maunal locking hubs, what could this be? bad u joints or is it just front my truck being cold? cuz it get to like -15 everynight here so maybe its just cold an stiff?

 

[4x4junkie]

Describe the knocking sound.
Does it go away while you're on the brakes?

Happen in 2WD? 4WD? Both?

 

[MUDDING B-3000]

no it doesnt go off when i hit the brakes, it happens in 2wd lock 4wd locks an 2wd unlock, i was told it might be one of my front u joints so i check them an i found one loose one on the front axle so igoin to replaced all 3 of them an see if that helps.