Peterbilt 389 Glider Dash Knobs

Frequently Asked Questions About Peterbilt 389 Glider Dash Knobs

What are dash knobs used for on the Peterbilt 389?

Dash knobs are the control knobs used on switches, valves, and levers throughout the cab, including items like heater and defroster controls, headlight switches, wiper controls, and other dash-mounted hardware. They are primarily a functional component, though many drivers also use them to add a personalized touch to the interior.

Will these knobs fit my Peterbilt 389 glider kit truck?

Most knobs in this category are designed to match the stem sizes and mounting styles used on Peterbilt 389 glider models, but stem diameter, shaft length, and set screw placement can vary depending on the specific switch or valve you are replacing. Before ordering, check the existing knob or switch stem measurements against the product specifications listed on each item to confirm a proper fit.

What materials and finishes are available?

Dash knobs are typically offered in materials such as chrome-plated plastic, aluminum, and billet steel, with finish options ranging from polished chrome to brushed or anodized looks. Material and finish affect both appearance and durability, so consider how the knob will hold up to daily handling and cab conditions when choosing an option.

How do I install a replacement dash knob?

Most dash knobs are secured either by a set screw on the side of the knob or by a friction-fit push-on design. To install, simply align the knob with the flat or splined section of the stem, then either tighten the set screw with a small hex or Allen wrench or press the knob firmly into place until it seats securely. Always confirm the knob is seated fully and does not spin freely on the stem before returning the truck to service.

Can I mix and match knob styles for a custom dash look?

Yes, many drivers choose different knob styles or finishes to distinguish between controls or to match other chrome and billet accessories in the cab. Just be sure that any knob you select is compatible with the specific switch or valve stem it will be installed on so that function is not compromised for the sake of appearance.