My rear end is roaring and getting worse I have a 2004 f-150 fx4 I'm not sure what gears are in it a buddy told me my pinion gear is loose cuz I can shake my drive shaft up and down with my hand about how much would it be for me to just throw some new gears in it at home

 

You probly just need new bearings. Pinion bearings, carrier bearings, and both axle bearings while your at it. Did u run the fluid low or get water in your diff fluid from offroading?? bearings dont just go usually due to poor lubrication.

 

I probally ran the fluid low because it is leaking and it wouldn't surpize me if I got water in it

 

Yea so I'm almost positive its bearings they sell bearing kits for like 80 bucks I think.

 

If there has been that much play in the pinion for a while your gears are probably ruined also (change of wear pattern). Better plan on total overhaul.

 

It's been like this for about a week and I can shake my drive shaft just barley

 

You 'might' be ok..no guarantees..if it was mine and had to replace all the bearings, you can bet I would go the extra mile and do the gears also.

 

I would like to but have no idea what it would cost iv never messed with gears in these newer trucks