I searched and searched for the howling problem for the F150's and found and had people reply that it is most likely the rear end. And my truck (99 F150 2WD) has 186,000 miles on it and the howling noise is annoying! And It prolly needs a rebuild with all those miles. So I want to rebuild it but I dont want to spend all the money because I am going to college. But I am taking automotive classes, so should I try to rebuild it myself in class? or should I let a professional do it? I am just trying to save money by doing it myself.

 

anyone suggestions?

 

do it urself in class. most schools will let u work on ur own stuff and dont charge for labor. u will get the experience of doing it, and ull want to make sure u do it right because u r the one that will have to live with it. plus ur teachers will be there to help you and they should know what they are doing, probably as good or better than someone in a shop would.

 

Being able to setup gears in an axle is a great tool to have. I wish I knew how to set them up.

I was going to post to just find another axle in a boneyard but since you have access to someone to help you learn how to set up gears, then go that route, you wont be sorry. It might cost a little more money but you'll be much better off in the long run.

 

When doing a rear end rebuild, what all I should i replace?

 

When you see what is required, you will find that not replacing all of the bearings will prove to be a waste of time. Since most of the bearings have been rotating roughly the same amount, and one or more has gone (going) bad, it is safe to say that all of them are on thier last leg.
Any good re-build will require a small shim pack, since some of the smaller shims may need to be replaced. You will keep in mind that the shims removed shoud be kept in the same order to get a baseline reference for the new installation. You may get away with re-using the old gear set, but only after careful inspection. With your master overhaul kit should come with all new seals and a new crush sleve. The rest is labor. Now if you have a LS unit, you will also need to rebuild it. The rear axle rebuild is not cheap.
Here is a smal link from others in your situation, and you can use the link to navigate for other assistance.
Good luck.

http://autorepair.about.com/library/a/1d/bl444d.htm

 

how hard is it to get a used differtial and swap another one in from a junkyard?

 

probably actually cheaper and easier than any other option

 

where can I find a used one at? for a good price?

 

You are going to shop for a complete axle, drum to drum, or disc to disc.
If you shop for just a differential, you may end up with just a carrier, and you need a complete axle assembly. You could re-use your brakes and such, but in order to eliminate any set-up of gears, you need the complete assembly, housing and all. Then all you have to do is unbolt the springs from the u-bolts, remove the driveshaft, swap out the brakes (if you buy an axle without them) and bolt up the new one. Simple as that.

 

I am looking around for a complete axle would like disc brakes. maybe junkyard?

 

Thats right. Junkyards are the way to go. Do make sure you can get some type of warranty, and inspect for obvious damage.
You will also need to know your current gear ratio so you can match it with the replacement unit.

 

This is a thread that is cirrently running. It indicates only one of the potential problems with trying to do this yourself. It also has a pic of a rear axle similar to yours.

https://www.ford-trucks.com/forums/6...rear-diff.html