The 5100 needs a sleeve for the F150 mount or they rattle? Are you sure. Also where do you get these sleeves! There was no mention of this at Bilstein web site.
Thanks.

 

Got a winner!! Shock should go boot (shaft) down. As for protection purposes, that shaft is substantially stronger and less prone to damage/dents than the body of the shock. Thus, the body goes up for protection purposes. But it also has some to do with the valving/internals as well. As for mud, gunk, and what ever else was mentioned getting on the shaft, these shocks have a scraper (most shocks do) who's sole purpose in life is to clean the shaft off as it compresses to prevent any grit or grime from damaging the seals, much less getting in the shock.

I am somewhat surprised to learn that the NBS trucks have the same mounting style at both ends of the shock?? The older trucks were not like this, thus making installation a one-way option. Those are always mounted body up. Look at any tough, off road shock...Edelbrocks, FabTech, etc...body up! And most guys don't even run any boots!

 

You always put the most mass(body)up to help keep the unsprung weight down. Mount them as close to the ball joint/drive wheel as you can. Ford finally did that. I've got to move mine on my 2002.

 

Ok to many competing answers. So i went to the horses mouth and called Bilstein. They said there is a blue Bilstein sticker on the shock and you should be able to read that when installed correctly. It should not be upside down.
Just checked mine and that would put the boot down.

Now ive got you!
Your thinking that in all the commotion did i shoot 5 or 6. Are you feeling lucky! Well are you punk?

Now run out side and check yours are in right.

Later.

 

No absolutely not. My truck must be upside down.

 

???? I guess yours are in wrong by your comment. Which by the way is a little confusing.

Does No absolutely not = Im wrong/ Bilstein the designer of the shock is wrong about how they install??? hmmmmm.

Maybe yours are installed differently if there not the 5100's. Just a thought.

 

If you have the Bilstein 5100's designed for 0-2 inches of lift install the rears with the boot down (its what I have on my truck and that's how I installed them per Bilstein instructions) but the Bilstein 5100's designed for 4-6 inches of lift (the ones that come with the RCD kit or you can buy them separately for the Rancho kit or Superlift kit) you have to install the rears with the boot up. Problem solved, do the research and you'll find the anwsers

 

Hey 07fx4silver,

How is the ride compared to the old stock shocks. I see some pics of your shocks in your gallery. Does your front shock have a boot as mine did not come with one like the rear?
I see you have the 2" leveling kit also. Did you re-use them or use the 1" or 2" spring perch location on the front 5100 shock.
I'm trying to decide whether to re-use my 2" leveling kit or the 1'' or 2'' option on the shock.
Thanks.

 

Here are some pics









The front coilover shock does not come with a boot. Ride is much more controlled and responsive over stock but get them off the pavement because this is where they really shine. It's up to you what you want to do for lift but since you have a 2" leveling kit I would ditch that and just use the shocks for your lift. I re-used my 2.5" leveling kit cause I want all the lift I can get, even if it's only half an inch more.

 

The more weight a supporting spring has to control the harder its job is. Aluminum wheels/control arms, upside down shocks, strut suspension, etc. are all made for lower unsprung weight. This allows better handling.

 

mine are upside down, no problems at all. I dont think it really matters up or down. If im correct the 5125's come with the 1/2 sleeve in them since they are generic and youll have to go to summit and get the 12mm step down. I was told the shop that did the lift should have sleeves, but i didnt want to drive back to dallas...

 

I called Bilstein and the guy I talked to said it didn't matter if the boot was up or down!