Our Colorado’s Rancho suspension continues to impress. Its quality is top-tier. One addition was needed, though.
We want our 4x4s to work well at crawling speeds. We also want them to perform well at high speeds, on the pavement or in the dirt. To do this, quality shock absorbers are necessary.
For the rear of the Colorado,...
For the rear of the Colorado, we chose Bilstein 5165 Universal Fit shocks. Their remote reservoir dramatically increases shock oil capacity for good heat dissipation and damping sensitivity. Special swivel banjo fittings on the reservoir hose allow for 360 degrees of rotation. For increased wheel travel and more shaft movement, the “floating” dividing piston is located in the reservoir. Space was tight up front, so we chose Bilstein 5125 Universal Fit shocks. The 5125s feature self-adjusting deflecting disc valving, independent rebound and compression tuning, and their high-flow piston reduces harshness. Both shocks are sold by length and valving and require additional hardware when used in the Colorado’s OE mounting points. The OE bushings and sleeves can be pressed out of the stock shocks and reused, but we had Bilstein send new hardware.
Bilstein offers their 4600 Series shocks for stock Chevrolet Colorado/GMC Canyon pickups. They’re a wise upgrade from OE. As we have a 4-inch lift Rancho suspension system on our Colorado, we went to Bilstein’s “Universal Fit” line of shocks that are sold by length and valving, but require additional hardware when used in OE shock brackets. For many applications, the OE bushings and sleeves can be pressed out of the old shocks and reused in the Bilsteins, but we went with new parts.
We chose new Bilstein 5165 reservoir shocks for the rear. Along with the shocks, Bilstein sent bonded bushings/bar pins for the upper rear mounts and sleeves for the bottom.
Up front, the configuration of the upper shock mount made using a reservoir shock impossible, so we chose 5125 monotube shocks. The top is a stud mount—no changes needed. We pressed in new bottom bushings and sleeves. The bushings and sleeves were too wide for the Colorado’s bottom mounting bracket, so they were ground down about 1/4-inch to fit.
Once the bushings and sleeves...
Once the bushings and sleeves were installed, the Bilsteins installed easily in the Colorado’s OE shock brackets.
Once the 5165/5125 Bilsteins were installed, we took the Colorado for a quick spin. Wow! What a difference. Compression and rebound valving is just about perfect. The Colorado no longer bounces over bumps. The ride is firm, yet controlled and comfortable. OK—we have to say it. The Bilsteins make the Colorado feel almost like a German sports sedan.
Next—winch, rocker guards, and Falken WildPeak tires.

We pressed in a bonded bar...

We pressed in a bonded bar pin and bushing on top and a new bushing with sleeve in the bottom of the 5165s. The reservoir has a long hose and can be mounted on the frame or body. We were pressed for time, so used the spacer and clamps included.

When mounting the reservoir...

When mounting the reservoir to the shock body on the passenger side, it has to be mounted between the muffler and the axle for clearance.

The front 5125’s top mount...

The front 5125’s top mount is a stud, so no changes were necessary. The bottom needed a new bushing and sleeve. The bushing and sleeve were too wide, so were ground down about 1/4-inch to fit the OE shock bracket.