Peterbilt 357/378 Dash Knobs

Frequently Asked Questions About Peterbilt 357/378 Dash Knobs

What are dash knobs used for on the Peterbilt 357/378?

Dash knobs are the control knobs found on the dashboard and console that operate functions such as headlights, panel lighting, heater and A/C controls, fan speed, wiper controls, and other dash-mounted switches. They are a small but frequently handled part of the cab, so they tend to wear, crack, or lose their printed labels over time and often need replacing.

Will these dash knobs fit my specific Peterbilt 357 or 378 model year?

Dash knob fitment can vary depending on the year of your truck and the type of control or switch shaft it attaches to, since Peterbilt updated interior components over different production runs. Always check the listed shaft size, spline pattern, and any noted year range on the product page, and compare it to the knob you are replacing before ordering.

What materials and finishes are available for these knobs?

Dash knobs are commonly available in materials like chrome-plated plastic or metal, and finishes range from polished chrome to satin or black textured options. Choosing a finish that matches your existing dash hardware helps keep a consistent look throughout the cab.

How do I install a replacement dash knob?

Most dash knobs simply pull or twist off the existing control shaft, though some are secured with a small set screw or retaining clip. Once removed, the new knob is pressed or twisted onto the shaft, and if there is a set screw, it should be tightened to keep the knob from spinning loosely. No special tools are typically needed, but a small screwdriver may be helpful for knobs with set screws.

Will the labels or symbols on the knobs match my original dash layout?

Many replacement knobs are designed to mirror the original OEM labeling, such as icons or text for lights, fan, or temperature, but designs can vary by manufacturer. Review the product images and description closely to confirm the labeling matches the function you need before purchasing.