SOunds liek it is a cable problem. It is not extremely hard to replace the cable you jsut need to have small hands sorta to get in behind the dash. You can find the cable at the back end of the transmission tail shaft. It will be on the passenger side and screw into the side of the tail shaft. IT will then run up to the body of the truck and into the firewall somewhere around where the steering shaft comes out of the firewall. You will need to remove the gauge cluster to get to the back of the spedometer to unhook it from the back. There are going to be 2-4 screws that hold the trim in to place. Remove those then you will see the screws that hold the actual guage cluster into place. Remove those and you can pull the cluster out a little bit to get your hand in behind it to unhook the cable. I am not sure aobut your particular truck but some of the Toyota vehicles have a two piece cable. You should be able to look at it and tell if it is is two piece or one pretty easily. HEre is a link to a site that will give a picture of where the cable comes outof the transmission. there is also one that gives you a blow up of the instrument cluster and where all the screws are to get it out. You dont have to do everything it says you only want to take apart the stuff for the actual cluster, not the entire dash assembly. I hope this helps a little bit. As faras taking it to a shop to have it done if they know waht they are doing they can probably have it done in less than an hour.
Oh yeah by the way welcome to Toyota Nation and enjoy your time here.
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