The truck shakes badly under braking now, and I'm pretty sure its the wheel bearings. The only problem is I have NO knowledge when it comes to front suspension/axle stuff. How hard is it to replace bearings and are there any special tools needed? I really don't want to start taking it apart and find out I dont have what I need. What all has to come off? I need step-by-step instructions; I only know what I learn on here.

 

If it is only doing it while braking I would say your rotors are worped not the bearings they would be all the time. Does you steering wheel shake or the front of the truck bounce a little?

 

Yes and yes. The brakes were just checked and the guy said they were fine. It also makes an ugly screeching noise on and off from the front left. I'll get out and take a look to see what I think when I'm changing the oil today; I was just wondering, if it is the wheel bearings, how hard they are to replace?

 

front wheel bearings come out when you pull the rotor, ay least on a 2wd anyway.

 

Wheel bearing replacement is a several hour job on a W250. They do need to be repacked every couple years. What I would do is disassemble it, clean, inspect and repack the bearings, and replace as necessary, and have the rotors machined while it's apart. While it's apart, remove the spindles, and service the needle bearings that the stub-shafts ride on. Give the axle joints a good check. If they're questionable, you might as well replace them while you're in there.

I think the cause of your concern is rotor warpage or thickness variation. Whoever said your brakes are "ok" might have simply been basing that on a visual inspection of remaining lining, without measuring rotor runout or having a road test. I have noticed automatic trucks to have far worse rotor warpage concerns than manual trucks. The brakes overheat because nobody seems to downshift an automatic when stopping, letting the brakes do all the work.

 

4x4 need a socket special

 

yeah that socket was around 30 bux. for a castle nut, i believe.