I recently installed a set of Bilstein 7100 reservoir shock absorbers on the front of my Ranger:
https://www.ranger-forums.com/forum2...ad.php?t=27975

I liked how the swap turned out, so I decided to get a matching set of 7100's for the rear of the truck. I chose a set of 12" travel 'short body' shocks that have almost exactly the same compressed length as stock Ranger 4x4 shocks but allow 2" of additional rebound travel.

My original (wishful) thinking was that, unlike the front, the rear swap would be a simple bolt-on. Well, not exactly. It turned out that there were a couple of problems to overcome.

The first issue was the mounts. These are universal shocks that are sold under the assumption that mounts will be built specifically for them. They are not offered as a direct replacement for any specific OE shock absorber.

7100s come from Bilstein with very nice 1/2" bore Heim joints installed. That's fine for the Ranger lower mounts which use 12mm bolts and Bilstein had thoughtfully included 1/2" to 12mm adapters.

The upper mount is a different story. Rangers have a shouldered stud mount on top that has a 16mm OD. That is very close to 5/8" and there is obviously no way that a 1/2" Heim is going to slide on to a ~5/8" stud. I ended up removing the upper Heims and substituting some polyurethane bushings leftover from a James Duff traction bar kit. All I had to do to make them fit was turn a 26mm OD step on each JD bushing to match the ID of the Bilstein upper eye.

Now I thought I was truly home free .... until I tried to mount the driver side shock. The reservoir hose exits the shock body at about 45 degrees. If the hose is aimed up, it runs directly into the bottom of the bed with no room to turn. Flip the shock over and the hose fitting hits part of the spare tire crossmember.

Undaunted, I ripped the box off and broke out the MIG. To make some room for the reservoir hose, I cut a notch in the crossmember and reinforced it with side plates welded in. There weren't many options for the mounting of the reservoir itself. I finally decided to put it between the evap canister and the spare tire winch. A piece of motorcycle exhaust tubing was welded to the spare bracket to make a place to clamp the polyurethane reservoir mounts that came with the shocks. In this location, the Schrader valve can be accessed easily with the spare dropped. The bed still has to be lifted to remove the DS shock but that was a given regardless of where the reservoir was placed.



By comparison, the passenger side was easy. I just used the curve on the top edge of the frame as a mounting point and clamped it on.

 

Geez Bob... way to make me feel inferior AGAIN!

 

yeah. dont work too hard on that. nice work. im more of a OEM fit kinda person

 

Awesome work Bob! I just installed your old Bilsteins :)

 

You are the shiz-nazz Bob. Dang man, many props.

Brenton

 

looks good bob..ive always wanted some of those with the seperate resv.

 

Awesome Bob! Very cool!

So how's it ride?

 

I think that's what Bob was going for.. and it turned out freakin crazy.



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damn.. 7100's up front AND back?!? that's insane. How DOES it right?

 

I haven't had it off road yet but I have tried a couple of washboard dirt roads. The front is great but the rear is a little bit choppy. I guess that you have to expect some of that in a nearly stock small pickup.

At first, I was concerned that the Ranger damping stack wouldn't be compatible with the full size Chevy spring swap but, when I checked the Bilstein valving guide, the recommended damping was the same for both Rangers and full size pickups (255/70).

 

When you talk about valving stack, is that more or less the 'stiffness' of the shock? Would softening them up do any good on the dirt roads? Or would you want them stiffer?

 

Yes, Bilstein offers 6 different valving options for the 7100s. I am using Bilstein's recommended settings:

Front:
Part number suffix "06" AKA 360/80
This is 800 Newtons compression force and 3600 Newtons rebound force measured at 0.52 meter/sec.

Rear:
Part number suffix "04" AKA 255/70.
This is 700 Newtons compression force and 2550 N rebound force measured at 0.52 m/s.

Higher numbers mean more restrictive or "firmer" damping. Lower numbers are softer. The shocks can be disassembled and revalved to any of the 6 settings. I am going to drive them for awhile as received to see if there is any break-in change. They can always be revalved later if necessary.

 

nice job.....