Offroad Trailblazers and Envoys

Where have you driven your Trailblazer? has the information you need to modify your GMT360/70
for exploration and discovery of the unpaved areas in the world.

Check out our Articles below and join the forum!
Visit the Forums

View the latest news posts and updates from ORTB.

Lifts / Suspension

Vehicle suspension maintenance information and lifting articles.

Wheels / Tires

Relating to everything wheels and tires.

Differentials / Axles

Look in here for information about drivelines and gearing.


Components built by members, and tips for your own fabrication.

Electrical / Communication

Batteries, wires, antennas, and buttons.


Stuck? We've got info to help you get out safely.

Utilities & Resources

Calculators, technical documents, and general resources.


Want to spend some time outside? You'll find info about that right here.


This section helps you find and resolve common problems.

Latest Forum Posts

I used Surco crossbars on factory rails for a while, but before I had a tent, I had a very overloaded roof basket. Started bending the factory rails w [Go To Post]

Okay, I appreciate you getting back to me. I will try it out, and see how it goes while I wait for my surco cross bars. With the surco cross bars, I h [Go To Post]

I wouldn't know if the factory ones would work. I took my factory rack off about 10 years ago and can't remember how sturdy they were. If it [Go To Post]