Had to go out of town for work yestesday. Drove my truck to work and as I turned on to the road to my office there was a loud grinding sound that started. But I would hit a bump and it would quite hit another bump start again so on & so on. Turned into the parking lot at work and it quite. So now I'm in Mobile, AL till friday and I had a friend of mine who is a mechanic go get my truck. He drove it home about 30 miles and said it would do it off and on like before. Got home tonight and checked both wheels with no slack in either. He thinks its a wheel bearing or spindle bearing. What do you guys think, and would driving it the 30 miles home tear up the front axle?

 

If it's home, I would not risk driving it anymore until you can tear into it. I would suspect that a grinding sound from the from front end means metal on metal contact. Any more driving would just tear up otherwise salvageable parts resulting in a larger repair cost.
Here's a good writeup on the needle bearing replacement/maintenance:

Welcome to guzzle's 4x4 Needle Bearing Maintenance Web Page

Just my opinion. Good luck.

 

Sounds like a bad hub assembly. I had the same problem and it turned out to be the passenger side. I jacked the truck up and I found that there was more up and down movement then there should have been. I got a new Ford hub assembly and re-greased it all, now no more grinding noise. As Ponyboychris said, guzzels web site has it all there.

 

Well if that is it, I have been looking online and a new hub assy is $550 to $800 for an early 99 4x4. Is that about right I thought they were more like $250 to $300?

 

Try giving Ed (FTE PartsGuy - member here) a call or shoot him a PM. He sells OEM parts and good discounts.

Here's his website:

Th!nk Parts Guy/FTE Parts Guy

 

Yup... new hub assembly.
Hard to believe it costs as much as it does but... that was my exact issue too.

 

I got mine from Your Premiere Source for Ford Truck Parts | Powerstrokeshop.com and paid 385.72 for a kit which had the hub assembl the o-rings and the back seal needed. I would definitely recommend them.

 

Before I'd go dropping tons of money on parts to "hopefully" fix the problem, check the carrier bearing. Mine started that same way about 3+ weeks ago. Hit a bump and it'd start grinding, hit another and it may quit. It got to where it was going it all the time.

I ended up taking it into a shop only because I didn't have the time to work on it myself. They finally determined it to get the carrier bearing after the unbolted it from the crossmember and spun it on the shaft. Even though the old one didn't look bad on a visual inspection and didn't show any play when trying to spin the driveshaft in it, when spun around the shaft, that's when they found it. Replaced it and now it runs down the road much smoother than it did before!!

Not to say that it couldn't or isn't a hub or wheel bearing, but at least check the carrier or have it checked also before you go too far. Good luck.