Threat problems as a warrior
Warriors are going to have threat issues for a few basic reasons and those issues usually occur in the first 3 seconds or so of a pull. First, warriors usually have vigilance on the wrong person or not at all. In a five man run, vig should be up on the party member most likely to take damage, such as melee dos, because vengance will activate and increase your attack power obviously giving you the ability to generate more threat. Second, if you have a crit heavy dps pulling off you right out of the gate your opening the pull with the wrong abilities. Heroic throw should be first when possible ( followed by charge of course) then shield slam and then revenge because by that time revenge will almost always be active. These abilities will generate all the threat you need to keep a huntard from pulling off you. Don't be afraid to mark the first mob to go down. Just because there is no special ability you are trying to prevent, it just alleviates Threat issues because if all dps are focused on the same mob no aoe damage is capable of pulling off you. If you mark the first mob that will give you time for rend and thunder clap and cleave to ensure that the rest of the pull will always stay on you. When I do a pull like this, once we get to the next mob to be killed I have around 1000% threat so there is no crit that is gonna pull off me. As for raids with more than one tank you should have vigilence up on the other tank. The other tank is taking damage constantly so vengeance is procing and your taunt is now spammable. for example, during the Beth telic fight I have vig up on the upper level tank so I can taunt all the spinners down in a matter of seconds. Warriors are sweet tanks but because you don't have the pally threat increasing ability and you don't do as much pure dps as a DK you just have to use your abilities correctly. Lastly, if you have an second tank pulling off you then you are not using shield slam and revenge enough. These abilities, for me have almost caused wipes because I have pulled aggro back too soon before damage stacks have dropped off. Follow this my friend and you will soon be in the ranks of epic tankdom.