Factory "Rancho" Tenneco Shocks Love 'Em or Hate 'Em/Upgraded

Sinkhole · May 24, 2019

I have a 2015 Z71 with the OEM Rancho shocks still. Still have them not because I love them, but simply because I see no need to replace them, yet. The ride is great when I compare it to my 2005 Silverado with Z85 suspension and Bilstein 4600 Shocks. When I bought my truck I drove several other trucks including an LTZ (Not a Z71) which rode much smoother on road but had a lot worse rebound on bumps. I am trying to compare my experience between my '05 and my '15 but there are a large number of variables that color the results. Tires, truck length, weight, height. All these factors will affect "ride". I put that in quotes because I think there is a difference in terms being used here. To me "ride" means the overall feel of the on-road/off-road experience. "Control" is an entirely different thing. The video posted many pages back shows nothing but a lack of "control" on vehicle driven way to fast for the conditions. You can not expect a truck with OEM suspension to handle conditions like that at those speeds nearly as well as a truck with a suspension designed for those conditions like a Trophy Truck for example. In my experience "ride" vs "control" is a compromise. You tend to give up control for "ride" and give up comfort for "control". There are some exceptions to this but those usually involve doing more than just a Strut/Shock replacement. Also "ride" is very subjective. Person A might find a soft cushy ride unacceptable while Person B is looking for that quality. The other thing to remember is ride is not solely affected by your shocks. Tires play a large part of it, but this is not about tires.
I personally will be getting rid of the OEM Rancho shocks when they are at life's end. I will be replacing them with either Bilstein 5100's or Fox 2.0 IFP's. Reason 1 is cost. The OEM replacement Ranchos are very expensive for what they are, and 2 I am looking for better control.

2kwik4u · May 24, 2019

I was thinking some more about this on the way into work this morning (we were out of coffee and I had to do something to keep my mind busy for 40 minutes)......

The best explanation I could come up with between the two trucks I drove is that my personal truck ('15 SLT Z71) is very "nervous" over bumps, while the loaner truck ('18 LT Z71) was very "composed" over most bumps.

For example.....There is a left hand sweeping curve on the expressway in the morning. Large pothole on the left side of the lane right in the middle of the curve. It's got a "sharp" edge on it, is about the size of a frying pan, and is 1-layer of concrete deep. City has fixed it multiple times and it keeps coming back. My truck hits that and it hits hard. I can feel it in the seat, and steering wheel. The front and back end scoot over a shade, and the whole truck feels largely unsettled. The loaner truck would take that bump in stride. It wasn't as much of a "bang" as it was a "thud" in the feeling. It was general softer overall, and the truck remained mostly settled throughout the impact.

The constant "banging" and "nervousness" of my truck is what I'm looking to eliminate. I want a nice "composed" ride. I want it to take the hits, but continue on it's intended path, and reduce some of the impact into the cab. The plan is to find some softer sidewalled tires, and a new set of shocks and see where that gets me.

Sierra Dan · May 24, 2019

43 minutes ago, 2kwik4u said:

I was thinking some more about this on the way into work this morning (we were out of coffee and I had to do something to keep my mind busy for 40 minutes)......

The best explanation I could come up with between the two trucks I drove is that my personal truck ('15 SLT Z71) is very "nervous" over bumps, while the loaner truck ('18 LT Z71) was very "composed" over most bumps.

For example.....There is a left hand sweeping curve on the expressway in the morning. Large pothole on the left side of the lane right in the middle of the curve. It's got a "sharp" edge on it, is about the size of a frying pan, and is 1-layer of concrete deep. City has fixed it multiple times and it keeps coming back. My truck hits that and it hits hard. I can feel it in the seat, and steering wheel. The front and back end scoot over a shade, and the whole truck feels largely unsettled. The loaner truck would take that bump in stride. It wasn't as much of a "bang" as it was a "thud" in the feeling. It was general softer overall, and the truck remained mostly settled throughout the impact.

The constant "banging" and "nervousness" of my truck is what I'm looking to eliminate. I want a nice "composed" ride. I want it to take the hits, but continue on it's intended path, and reduce some of the impact into the cab. The plan is to find some softer sidewalled tires, and a new set of shocks and see where that gets me.

You will have a planted, composed ride with Bilsteins or any other Monotube type shock.

Btw, Welcome to the site and Club 2kwik4u

2kwik4u · May 24, 2019

13 minutes ago, Sierra Dan said:

You will have a planted, composed ride with Bilsteins or any other Monotube type shock.

Btw, Welcome to the site and Club 2kwik4u

Thanks for the welcome, and the vote for some monotubes.

Been lurking for 18mo or so. Just recently started being more active here.

mdreynolds · August 4, 2020

On 8/28/2018 at 11:28 AM, Sierra Dan said:

This Brand new Off Road Sierra AT4 truck has seemingly the same Ranchos as our current K2's

Notice the Bounce and out of control body roll? Look familiar ?

I want to see GM offer a better shock off the factory line for such a cool, smart targeted Package in the AT4 and Trail Boss

https://www.youtube.com/watch?time_continue=3&v=jgvVs3RZQuI

My understanding the shocks on your 2016 along with all the 2019 and 2020 Z-71/X-31 have twin tube Ranchos, the TrailBoss/AT4 have Monotube Ranchos.

Not knowing the difference in shocks at the time, But with driving the 2020 Sierra SLT with Z-31 then the Sierra AT4, the AT4 was definitely a bit better, even my wife that doesn't know the difference between a Shock and a Spark Plug even chimed in that the ride on the AT4 was better. At that time is when I researched and found the different style shocks used.

Edited August 4, 2020 by mdreynolds