I was re-connecting the outer tie rod end to the spindle and noticed that the castle nut would not tighten, the threads are not stripped. I pulled back the rubber boot and spun the nut with a wrench and the whole inside is spinning and will not tighten. I'm assuming the tie rod end is bad and I need a new one but I wanted to check with you guys first. Thanks

Sounds like you're re-using an old tierod. Are the threads clean? Has the nut bottomed out, no threads left? Could be that the tierod just hasn't pulled down into the spindle arm far even to keep it from spinning. If that's the case put a scewdriver inbetween the nut and the spindle arm and try pulling it down in so it seats.

If you've run out of threads then either the tierod or spindle arm is shot.

I use an impact, when I am on the road with no air then use some channel locks to squeeze the tie rod into the spindle and then tighten the nut.

Using a impact works nice. Or take a block of wood or a soft plastic style hammer, pound the tie rod in and then try tightening.

Chris.

also if you have a problem and the channel locks don't quite do it then put a washer or two in between the castle nut and the arm
once it seats then remove the nut and take out the washers and reinstall the nut
don't forget to use a new cotter pin though

There are plenty of threads left but no they are not clean. Sounds like I didn't get the tie rod end seated in the spindle all the way. I'll give it another try today and see what happens. Thanks for the replies.