Peterbilt 357/378 Mirrors & Acc.

Frequently Asked Questions About Peterbilt 357/378 Mirrors & Acc.

Will these mirrors fit my Peterbilt 357 or 378 without modification?

Most mirrors and mirror accessories in this category are designed to bolt directly onto the factory mounting arms and brackets used on the Peterbilt 357 and 378 models. However, mirror setups can vary by production year and cab configuration, so it's important to check the listed specifications and compare them to your truck's existing mirror arms, mounting holes, and wiring connections before ordering. If you're unsure, comparing your OEM part number to the product description or reaching out to our team can help confirm fit.

What's the difference between the hood-mounted and door-mounted mirror options?

Hood-mounted mirrors attach lower on the truck near the fender, giving a different sightline than door-mounted mirrors, which sit higher on the cab door. Some Peterbilt 357/378 setups use one or the other, and some use both together. Check your truck's current mirror mounting locations to determine which style you need, since hood and door mirrors typically aren't interchangeable.

Do the heated and powered mirrors require special wiring or connectors?

Heated and power-adjustable mirrors typically use factory-style plug-in connectors that match the wiring harness already run to your mirror arms. In most cases, if your truck came equipped with heated or powered mirrors from the factory, the replacement will use the same connection points. If you're upgrading from manual mirrors to heated or powered ones, additional wiring may be needed, so it's worth verifying your truck's existing electrical setup first.

What finish options are available, and how do they hold up over time?

Mirror housings and brackets are commonly available in chrome-plated finishes as well as primed or black finishes ready for paint matching. Chrome offers a polished look but can show scratches and pitting over time with road exposure, while painted or powder-coated finishes tend to hide minor wear better. Choosing the right finish often comes down to matching your existing truck appearance and personal maintenance preference.

Can I replace just the mirror glass, or do I need the entire mirror head?

Many of our listings include standalone replacement glass for mirrors that are cracked or worn but still have a functional housing and mounting arm. If only the glass is damaged, replacing just the glass insert is usually the more affordable option. If the housing, arm, or motor is damaged, you'll want to replace the complete mirror assembly instead.