i have a 99 f150 ext cab 4x4 4.6L and i replaced all the shocks on it last summer... and a few months ago i hauled a pretty heavy uhaul trailer and my suspension has went to crap...i take off my rear shocks and when i compress them for the first time they dont seem to do much, but once they fully extend and i compress them again they seem to be fine..but after a few days of riding they go back to being crap...so im guessing that there is some kind of internal leak or something with them and need to be replaced...but how can i tell if the springs are still good....cause my rear ends is riding a little lower than it should..im not sure if it is because of the bad shocks or the springs..and ive also noticed that there 1 inch spacers on my body mounts and would this have any negative effect on using stock shocks?...and one more thing...what all consists of the front suspension??? is it just the shocks...???...sorry for the length...any comments will be greatly appreciated....thanks guys...

 

What kind of shocks did you buy? I am no shock expert (other than taking 'em off and putting 'em on-doing tomorrow), but as far as I know, they should always be difficult to compress and expand easily (as long as they are still good).
The shocks do just that, absorb shock from bad road etc, and really have nothing to do with the springs. You may have taken a little of the flex out of the springs depending how long the rear suspension was under load and for how long.
Spacers in the body will have no effect, the shocks mount from the axle to the frame.
It might be easier to ask what is not in the front suspension. Inner/outer tie rods, upper/lower ball joints, torsion bars, pitman arm and much more. If you are really interested to know, pick up a Chiltons manual or somthing similar at your local auto parts shop.
Unless you really know the history of the truck, you may need to replace springs. lol

 

i use monroe shocks...and the reason i was asking about the front suspension is that i replaced the front shocks a few months ago and i can bounce one corner of the front end up and down and it wont hardly stabilize itself...just continue the up and down motion still it stops gradually...so i guess i just got some duds up front then....ive just not had too much luck with shocks..haha....thanks for the post...

 

I was/am planning on buying Monroe reflex shocks and putting them on tomorrow. A little more expensive then their "entry level" shocks. You make want to look into your warranty.