Offroad Trailblazers and Envoys

Recovery Tools and Equipment

Tools and Equipment: A proper recovery kit will depend on which recoveries you will be performing. Passive Recovery: Jack Hi-Lift X-Jack Bottle jack Ladder Bridging Sand D-handle shovel Carpet strips Tire chains Lift-mate Larger jack base Dynamic Recovery: Another vehicle Proper anchor points on both vehicles Properly sized dynamic strap Static Hi-Lift Recovery: Hi-Lift Off […]

Static Vehicle Recovery (Winching)

Static Recovery: A static recovery derives the recovering force by steadily decreasing the length of the recovering system. Because this method is slower, it can provide much increased control and safety over a dynamic recovery. Anchor Points: Because of the recovery process here, the system needs an anchor. This can be a tree, a rock, […]

Dynamic Vehicle Recovery

Dynamic Recovery: A dynamic recovery derives its forces from the kinetic energy of a moving mass. Because of the method, it is important to ensure you are using an appropriate dynamic (stretchy) strap. Dynamic Recovery Straps: A dynamic recovery can be a simple method, provided that you have a second vehicle present. Dynamic recoveries derive […]

Passive Vehicle Recovery

Passive Recoveries: Passive recoveries are sometimes the simplest way to recover a vehicle, and often overlooked. People are quick to grab a strap and hook up to another vehicle without understanding that a few shovels of dirt could allow the vehicle to drive out safely under it’s own power. There are a few passive methods, […]

Assessing your Predicament

Assessing the situation As with any potentially hazardous situation, you always want to stop, take a breath, and slowly plan out your actions. The brutal truth is that most stuck situations are due to driver error – misreading the ground, or obstacle, or not understanding the vehicle limits. We all make mistakes here, often for […]

Factory Spring Part #’s and Associated Lift

PLEASE READ THE ENTIRE POST The table below works by looking up your stock front spring part number or tag color on the top line first. This can be found by looking at your stock spring tag, or by looking for the associated RPO code in the glove box (see below for RPO > Spring […]

Flipping Upper Control Arms

After lifting the suspension of our trucks, the upper ball joint can be put at some harsh angles. Especially when the suspension is flexed from side-to-side. A lot of users, including myself, have flipped the upper control arms to compensate for the angle of the ball joint. In order to “flip” your UCAs, you need […]

Trailer Brake Controller Installation

How to install a brake controller in a Trailblazer, Envoy, or other GMT360. Time: 0.5 – 1.5 hours (Depending on whether you solder or use butt connectors) Tools: 9/32” or 7mm Socket/Ratchet or Nut  Driver ¼” Socket and ¼” Drive Ratchet Wire Strippers Soldering Iron Solder Heat Shrink (medium and small sizes) Electrical Tape Dremel […]

Inner & Outer Tie Rod Replacement

Tie rods connect the rack and pinion to the steering knuckles.  They essentially transfer the lateral motion of the steering ram to the tires.  They go through a lot of abuse, especially off road.  Every bump, steering input, and braking motion put stress on the components. Tie rods are generally made up of two components.  […]

Suspension Lift Installation

This article is brought to you by BDS Suspensions. Front Installation 1.Park the vehicle and a clean, flat surface and block the rear wheels for safety. 2. Raise the front of the vehicle and support the frame with jack stands behind the lower control arms. 3. Remove the front wheels. 4. Disconnect the sway bar […]

Rear Wheel Bearing Replacement

I recently had a vibration problem in my 03 LS that didn’t go away after I replaced u-joints, balanced the tires, and checked the front wheel uni-bearing hubs (which were previously replaced). I also noticed a squeak and at times a rumble that seemed to be coming from the general direction of the rear axle […]

Rear Axle G80 Differential Rebuild

My G80 quit some time ago. I don’t know about you, but I like both of my rear wheels to lock up when I need them, so a rebuild was in order. Most other platforms simply ditch their G80’s in favor of something stronger. Unfortunately, us 8.0″ rear end Trailvoy’s don’t have that option. In […]

Front Wheel Hub / Bearing Replacement

This article covers how to diagnose and replace a front wheel bearing on a TrailBlazer (or Envoy). Wheel bearings are a complex and fairly expensive item for a TrailBlazer.  They serve to support the vertical weight of the vehicle, transfer lateral turning forces from the wheel to the body, transfer the power from the front […]

Transfer Case Operation: NVG 226 (NP8)

The New Venture Gear model NVG 226 transfer case is the dual speed, automatic, active transfer case in the Chevrolet TrailBlazer and GMC Envoy.  It provides five modes of operation: 2 HI Auto 4WD 4 HI 4 LO Neutral. General Operation: The Auto 4WD position allows the capability of an active transfer case, which provides […]

Front Axle 4WD Disconnect Rebuild

Theory of operation, common failures, and rebuilding:   Unit 56, above, is known as the front axle 4WD disconnect.  It resides on the passenger side of the oil pan, opposite of the front differential. The disconnect allows the front left and right wheels to spin independently of each other, and allows the front prop-shaft to […]

Trail Rating Guide

The following trail rating system is intended only as a guide. The one factor that can never be rated is driver experience. The ratings below assume a driver with a good knowledge of their vehicle’s capabilities and dimensions, line selection, and basic accident avoidance techniques like left foot braking, correcting for a skid, throttle control, […]

Vehicle Recovery

Understanding the basics: A lot of people make the mistake of just pulling out a winch line, wrapping it around a tree, and powering the winch in. No, no, no. That may get you unstuck, but it’s risky and can be dangerous. There are proper methods and proper steps that should be followed that can […]

Transmission Technical Documents – 4L60e

Through my research I’ve run across a few very helpful documents regarding the trailblazer transmission (the 4L60e).  I’ve amassed them here. Electronic Controls Document: Details of the internal wiring, pin-outs, and other electronic details. Hydraulic Schematic: (Left is the key document, right is the actual schematic file) Details of the internal hydraulic routing and their […]

Engine and Transmission Diagnostic Sheets

Below are trouble code diagnostic sheets for the TrailBlazer, Envoy, Rainier, Bravada, Ascender, and Saab 9-7 based on specific engines and model years. Year Engine Transmission LL8 4.2L I6 LM4 / LH6 5.3L V8 LS2 6.0L V8 (SS) LL8 4.2L I6 LM4 / LH6 5.3L V8 LS2 6.0L V8 (SS) 2002 PDF – – PDF […]

Diagnosing the 4WD System

We run into many questions where the owner realizes the front tires are not engaging when in a 4WD mode. The first and easiest step is to check for the appropriate sounds from your system.  With the engine off, but the key in the accessory position, switch the 4WD switch from 2HI to 4HI.  You […]

Differential Gear Ratio Calculator

Use this calculator table to determine the speeds and differences of differential gear ratios with different tire diameters.

Various Vehicle Specs.

4.2L 5.3L Years Details .: Torque Specs :. Lug Nuts X X 02-09 105 lbs/ft Brake Caliper Front Bolts X X 02-09 CV Axle Nut X X 02-09 103 lbs/ft Wheel Hub and Bearing Mounting Bolts X X 02-09 77 lbs/ft Outer Tie Rod X X 02-09 33 lbs/ft Inner Tie Rod X X 02-09 […]

Tire Size Calculator

Use this handy calculator to determine the differences between two different tire size dimensions.

Solid Axle Swap on a TrailBlazer

Two of our members have been crazy enough to hack off their entire suspension, and create an entirely new system based around a new solid front axle.  We wanted to highlight these creations today:   ChevyCrew   DirtyAnton

Straight Tie Rod Ends

ORTB team member, Fishsticks, came up with a solution to his constantly failing tie rods.  He found that 07 Silverado 2500HD tie rods worked as almost drop-in replacements.  More information in the link: