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!
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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

Hello,maybe someone know where to find the electric wiring circuit sheme for the gearbox 4L60-E. and gearbox repair manual. In the internet?Statistics [Go To Post]

Same meeting place as always, walmart gas station. These are the coordinates - 38.433346, -78.854626 or 38°26'00.1"N 78°51'16.7"W [Go To Post]

It's baby season apparently.I'm trying to make this trip, but our dayshifter's wife is about to sploop out anudder dumb kid, leaving ou [Go To Post]