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Peterbilt 357/378 Parts

Find the best Peterbilt 378 aftermarket parts in the business here at 4 State. The Peterbilt 378 semi truck represents all of the characteristics of the Peterbilt brand, and was a popular model with similar features to the Peterbilt 379. Pete truck models are a brand of choice for experienced truckers who need dependable semi trucks. 4 State Trucks has all the semi truck parts and accessories you need to make your Pete 378 stand out to showcase your unique personality. Whether you need aftermarket bumpers, exhaust, or fuel tanks, we've got you covered. Hit the open road in style and comfort with the best custom gear for your Peterbilt heavy duty truck or 18 wheeler.
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  • Phantom 1 Design Light Bezel 6.6875 X 2.6875 Inch W/ Triple Chrome Plating

    Phantom 1 Design Light Bezel 6.6875 X 2.6875 Inch W/ Triple Chrome Plating

    UNITED PACIFIC

    $5.99
    Light Bezel Phantom 1 Design 6.6875 X 2.6875 Inch W/ Triple Chrome Plating* High Quality Light Bezel* Made Of Injection Molded Plastic* Triple Chrome Plating Process* Phantom I Design* Designed To...
    09-160500006
    SKU:
    09-160500006
    Product Type:
    Lighting
    Make:
    Universal Items
    $5.99
    Qty in Cart: 0
    Price:
    $5.99
    Subtotal:
  • Low Profile Flat Red 2 Inch Round LED Clearance & Marker Light W/ Red Lens

    Low Profile Flat Red 2 Inch Round LED Clearance & Marker Light W/ Red Lens

    UNITED PACIFIC

    $4.99
    Low Profile Flat Red 2 Inch Round LED Marker Light W/ 2 Female Connector* High Quality Clearance/Marker Light* Low Profile Flat Design* Includes:  - Polycarbonate Lens (Sonically Sealed To Housing) ...
    09-1601060679
    SKU:
    09-1601060679
    Product Type:
    Lighting
    Make:
    Universal Items
    $4.99
    Qty in Cart: 0
    Price:
    $4.99
    Subtotal:
  • H8/H11/H16 Bulb 3.3125 Inch W/ 6 Diode White LED

    H8/H11/H16 Bulb 3.3125 Inch W/ 6 Diode White LED

    UNITED PACIFIC

    $43.99
    3.3125 Inch H8/H11/H16 Bulb W/ Fanless Design & 110 Lumens Output* High Quality H8/H11/H16 Bulb* H8/H11/H16 Style Plug* Fanless Design (Proprietary Aluminum Heat Sink Dissipates Excess Heat)*...
    09-1601001084
    SKU:
    09-1601001084
    Product Type:
    Lighting
    Make:
    Universal Items
    $43.99
    Qty in Cart: 0
    Price:
    $43.99
    Subtotal:
  • Amber/Pink Dual Revolution M1 Style Gen 4 LED Marker & Auxiliary Light W/ Clear Lens

    Amber/Pink Dual Revolution M1 Style Gen 4 LED Marker & Auxiliary Light W/ Clear Lens

    TRUX ACCESSORIES

    $35.59
    Amber/Pink Dual Revolution M1 Style Gen 4 LED Marker Light W/ Chrome ABS Plastic Bezel & 3 Male Bullet PlugsAdd versatile lighting and a custom look to your truck with theAmber/Pink Dual Revolution...
    09-160105316
    SKU:
    09-160105316
    Product Type:
    Lighting
    Make:
    Universal Items
    $35.59
    Qty in Cart: 0
    Price:
    $35.59
    Subtotal:
  • 10 Piece Mounting Hardware Set For Watermelon Cab Lights

    10 Piece Mounting Hardware Set For Watermelon Cab Lights

    UNITED PACIFIC

    $2.99
    Mounting Hardware Set Fits Watermelon Cab Lights 10 Piece* High Quality Mounting Hardware Set* Made of Stainless Steel* For Mounting Watermelon Cab Lights (Lights Not Included)* Includes:  - (10) M4...
    09-16080021
    SKU:
    09-16080021
    Product Type:
    Lighting
    Make:
    Universal Items
    $2.99
    Qty in Cart: 0
    Price:
    $2.99
    Subtotal:
  • 10 Pack 1157 Type Clear Bulb W/ Indexed Double Contact Bayonet Base

    10 Pack 1157 Type Clear Bulb W/ Indexed Double Contact Bayonet Base

    UNITED PACIFIC

    $5.99
    Clear Bulb 1157 Type W/ Indexed Double Contact Bayonet Base 10 Pack* High Quality Incandescent Bulb* 1157 Type* Indexed Double Contact Bayonet Base* Sold As Pack (10)* Warranty On Incandescent Bulbs...
    09-16000219
    SKU:
    09-16000219
    Product Type:
    Lighting
    Make:
    Universal Items
    $5.99
    Qty in Cart: 0
    Price:
    $5.99
    Subtotal:
  • Mini Rectangular Rubber Grommet 3.25 X 1.875 Inch 10 Pack

    Mini Rectangular Rubber Grommet 3.25 X 1.875 Inch 10 Pack

    UNITED PACIFIC

    $6.99
    10 Pack Mini Rectangular Rubber Grommet 3.25 X 1.875 Inch* High Quality Mini Rectangular Grommet* Made Of PVC Rubber* Designed For Mini Rectangular Style Lights (Lights Not Included)* Provides...
    09-16020548
    SKU:
    09-16020548
    Product Type:
    Lighting
    Make:
    Universal Items
    $6.99
    Qty in Cart: 0
    Price:
    $6.99
    Subtotal:
  • Thread On Air Valve Knob 50 Caliber Bullet Style 5/8 Inch

    Thread On Air Valve Knob 50 Caliber Bullet Style 5/8 Inch

    UNITED PACIFIC

    $38.99
    5/8 Inch 50 Caliber Bullet Style Air Valve Knob Thread On* High Quality Air Valve Knob* Made Of Die Cast Aluminum* 50 Caliber Bullet Style* Removable Thread Lock Included To Prevent Loosening Of...
    09-15010325
    SKU:
    09-15010325
    Product Type:
    Interior
    Make:
    Universal Items
    $38.99
    Qty in Cart: 0
    Price:
    $38.99
    Subtotal:
  • Amber/Red & Purple Dual Function Mini Round Double Face LED Clearance, Marker & Auxiliary Light W/ Clear Lens

    Amber/Red & Purple Dual Function Mini Round Double Face LED Clearance, Marker & Auxiliary Light W/ Clear Lens

    TRUX ACCESSORIES

    $50.99
    Amber/Red & Purple Dual Function Mini Round Double Face LED Marker Light W/ Zinc Alloy Housing & Single Mount PostGive your truck a unique lighting upgrade with theAmber/Red & Purple Dual Function...
    09-160105324
    SKU:
    09-160105324
    Product Type:
    Lighting
    Make:
    Universal Items
    $50.99
    Qty in Cart: 0
    Price:
    $50.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Automatic Mack Drive Axles Haldex Type Slack Adjuster W/ 6 Inch 16 Degree Angled Arm Replaces 135.2832

    Automatic Mack Drive Axles Haldex Type Slack Adjuster W/ 6 Inch 16 Degree Angled Arm Replaces 135.2832

    AFTERMARKET

    $78.99
    Automatic Mack Drive Axles Haldex Type Slack Adjuster W/ 1.5 Inch - 28 Spline Diameter Replaces 135.2832* High Quality Slack Adjuster* Automatic, Mack Drive Axles, Haldex Type* 28 Spline Count* 16...
    09-05170517
    SKU:
    09-05170517
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    $78.99
    Qty in Cart: 0
    Price:
    $78.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Automatic Gunite Type Slack Adjuster W/ 5.5 Inch Straight Arm Height

    Automatic Gunite Type Slack Adjuster W/ 5.5 Inch Straight Arm Height

    AFTERMARKET

    $78.99
    Automatic Gunite Type Slack Adjuster W/ 1.5 Inch - 28 Spline Diameter* High Quality Slack Adjuster* Automatic Gunite Type* 28 Spline Count* Straight Arm* Adjuster Dimensions:  - 5.5 Inch Arm Height ...
    09-05170516
    SKU:
    09-05170516
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    $78.99
    Qty in Cart: 0
    Price:
    $78.99
    Subtotal:
  • FREE SHIPPING
    ABS Hydraulic Motor Kit W/ Hydraulic Pump & Motor Assembly Replaces S21808, S4784079472

    ABS Hydraulic Motor Kit W/ Hydraulic Pump & Motor Assembly Replaces S21808, S4784079472

    AFTERMARKET

    $1,047.99
    Meritor ABS Hydraulic Pump & Motor Assembly Replaces S21808, S4784079472* High Quality ABS Hydraulic Motor Kit* Meritor ABS Hydraulic Pump And Motor Assembly* Used By HABS-E Braking Electronics* Sold...
    09-05170518
    SKU:
    09-05170518
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    $1,047.99
    Qty in Cart: 0
    Price:
    $1,047.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Black Poly Quarter Fender Kit 24 X 24 Inch W/ Round Tube Support Internal Mount Replaces 03101657, 1000-QF1900

    Black Poly Quarter Fender Kit 24 X 24 Inch W/ Round Tube Support Internal Mount Replaces 03101657, 1000-QF1900

    AFTERMARKET

    $109.99
    24 X 24 Inch Black Poly Quarter Fender Kit W/ Hardware Kit Replaces 03101657, 1000-QF1900* High Quality Quarter Fender Kit* Made Of Polycarbonate* Round Tube Support Internal Mount* Includes:  - (2)...
    09-11050636
    SKU:
    09-11050636
    Product Type:
    Rear Fenders
    Make:
    Universal Items
    $109.99
    Qty in Cart: 0
    Price:
    $109.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Automatic Drive Axle Haldex Type Slack Adjuster W/ 1.5 Inch 28 Spline Diameter Replaces 133.2830

    Automatic Drive Axle Haldex Type Slack Adjuster W/ 1.5 Inch 28 Spline Diameter Replaces 133.2830

    AFTERMARKET

    $78.99
    Automatic Drive Axle Haldex Type Slack Adjuster W/ 34 Degree Angled Arm & 2 Bolt Holes 5 And 6 Inch C To C Arm Height* High Quality Slack Adjuster* Automatic, Drive Axles, Haldex Type* 28 Spline...
    09-05170513
    SKU:
    09-05170513
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    $78.99
    Qty in Cart: 0
    Price:
    $78.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Automatic Gunite Type Slack Adjuster W/ 5.5 Inch Straight Arm Height Replaces 138.1010

    Automatic Gunite Type Slack Adjuster W/ 5.5 Inch Straight Arm Height Replaces 138.1010

    AFTERMARKET

    $78.99
    Automatic Gunite Type Slack Adjuster W/ 1.5 Inch - 28 Spline Diameter* High Quality Slack Adjuster* Automatic Gunite Type* 10 Spline Count* Straight Arm* Clevis Kit Gunite Type Included* Adjuster...
    09-05170514
    SKU:
    09-05170514
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    $78.99
    Qty in Cart: 0
    Price:
    $78.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Automatic, Drive Axles, Haldex Type Slack Adjuster W/ 5.5 Inch Arm Height & 1.5 Inch 28 Spline Diameter Replaces 135.2835

    Automatic, Drive Axles, Haldex Type Slack Adjuster W/ 5.5 Inch Arm Height & 1.5 Inch 28 Spline Diameter Replaces 135.2835

    AFTERMARKET

    $78.99
    Automatic, Drive Axles, Haldex Type Slack Adjuster W/ 34 Degree Angled Arm* High Quality Slack Adjuster* Automatic, Drive Axles, Haldex Type* 28 Spline Count* 34 Degree Angled Arm* Haldex Type...
    09-05170512
    SKU:
    09-05170512
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    $78.99
    Qty in Cart: 0
    Price:
    $78.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Spring Brake Valve W/ 3/8 Inch NPT Control & Supply Port Replaces 170.110171

    Spring Brake Valve W/ 3/8 Inch NPT Control & Supply Port Replaces 170.110171

    AFTERMARKET

    $72.99
    Spring Brake Valve W/ 1/2 & 3/8 Inch Reservoir Ports, 2 - 3/8 Inch Delivery Port* High Quality Spring Brake Valve* Protected Reservoir Spring Brake Control Valve* Control And Supply Ports Are...
    09-05170509
    SKU:
    09-05170509
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $72.99
    Qty in Cart: 0
    Price:
    $72.99
    Subtotal:
  • FREE SHIPPING OVER $249
    MV3 Dash Valve W/ Integral Push=Lock-Connect Fittings & 4 M6 X 1 - 6H Mounting Holes Replaces 170.800622WF, 5006257

    MV3 Dash Valve W/ Integral Push=Lock-Connect Fittings & 4 M6 X 1 - 6H Mounting Holes Replaces 170.800622WF, 5006257

    AFTERMARKET

    $200.99
    MV3 Dash Valve 5.8 X 1.5 Inch C To C W/ 5 - 3/8 Inch PLC Ports* High Quality Dash Valve* MV3 Type Dash Control Module With Integral Push-Lock-Connect Fittings* Trailer Trip Pressure 25-45 PSI*...
    09-05170508
    SKU:
    09-05170508
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $200.99
    Qty in Cart: 0
    Price:
    $200.99
    Subtotal:
  • FREE SHIPPING OVER $249
    T18/24 Disc Brake Chamber W/ 2.5 Inch Ram Stroke & 4 Inch Push Rod Replaces 179.SB1824DB, LCP1824D

    T18/24 Disc Brake Chamber W/ 2.5 Inch Ram Stroke & 4 Inch Push Rod Replaces 179.SB1824DB, LCP1824D

    AFTERMARKET

    $162.99
    T18/24 Disc Brake Chamber 9.125 Chamber Height & 4.75 Inch C To C Mount Hole Distance* High Quality Disc Brake Chamber* T18/24 Disc Brake* Spring Brake Chamber Type* (2) M16 - 1.5 X 1.75 Inch...
    09-05170510
    SKU:
    09-05170510
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $162.99
    Qty in Cart: 0
    Price:
    $162.99
    Subtotal:
  • FREE SHIPPING OVER $249
    FF2 Type Full Function Trailer Valve W/ 2 Way Check & 4 Port Relay Valves Replaces 170.KN28601

    FF2 Type Full Function Trailer Valve W/ 2 Way Check & 4 Port Relay Valves Replaces 170.KN28601

    AFTERMARKET

    $118.99
    FF2 Type Full Function Trailer Valve W/ Control, Spring Brake, Supply, Reservoir & Delivery Ports* High Quality Trailer Valve* FF2 Type Full Function Valve* Combines The Functions of Pressure...
    09-05170504
    SKU:
    09-05170504
    Product Type:
    Air, Electrical, & Safety
    Make:
    Universal Items
    $118.99
    Qty in Cart: 0
    Price:
    $118.99
    Subtotal:
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Adding your products to cart

The Peterbilt 357 and 378 are known for their no-nonsense durability and old-school style. Whether you’re hauling heavy loads or running construction jobs, these workhorses are built to last—and we’re here to help you keep them in top shape.

Why Choose Aftermarket Peterbilt 357/378 Truck Parts?

- Engineered for your model: Every part is made to fit and function with your 357 or 378—so you can skip the guesswork and get back to work. - Performance you can count on: Keep your truck running strong with engine, transmission, suspension, fiberglass Pete 357/378 hood shells, LED headlights, and cab lighting accessories designed to turn heads. - Trusted brands, proven quality: We only carry parts from manufacturers we trust, so you know you're getting durable, road-tested gear. - Quick shipping, expert help: Get your parts fast and reach out to our team if you need help finding the right fit—we’ve got your back.

Shop the Perfect Aftermarket Accessories for Peterbilt 357/378 Trucks


Whether you're restoring a classic or keeping your work truck rolling, our Peterbilt 357 and 378 parts are built to match the strength and legacy of these iconic models. We stock a wide selection of aftermarket and replacement parts designed specifically for Peterbilt 357 and 378 models. From critical mechanical components to sleek interior cab accessory upgrades, we’ve got what you need to maintain, repair, or customize your rig. Explore our full selection and get the parts you need to keep your rig road-ready.

Frequently Asked Questions About Peterbilt 357/378 Parts

What years and models are compatible with Peterbilt 357/378 parts?

Most aftermarket parts for Peterbilt 357/378 trucks are designed to fit models from 1987 through 2007. However, there are important differences between early models (1987-1999) and later models (2000-2007), particularly in hood mounting points and grille configurations. Always verify the specific year range listed for each part, as some components like bumpers and fenders may have changed mounting hole patterns after the 2000 model year update.

Are aftermarket bumpers as durable as OEM Peterbilt bumpers?

Quality aftermarket bumpers are typically made from 16-gauge steel (same as OEM) and feature triple chrome plating or powder coating for corrosion resistance. The main differences you'll find are in the finishing details and fitment precision. While a well-made aftermarket bumper can last just as long as OEM, pay attention to the warranty offered - reputable manufacturers typically provide at least a 1-year warranty on chrome finish and 3-5 years on structural integrity.

What tools and modifications are needed to install replacement parts?

Most bolt-on parts like bumpers, grilles, and headlight assemblies require basic hand tools including socket sets (typically 1/2" to 3/4"), wrenches, and a drill with metal bits for any minor adjustments. Common installation challenges include slight drilling to align mounting holes (especially on pre-2000 models) and adjusting bumper brackets for proper fitment. Professional installation typically takes 2-4 hours for major components like bumpers or hoods.

What's the difference between chrome, stainless steel, and painted finishes?

Chrome-plated steel offers the brightest mirror finish but requires regular polishing and can pit in harsh climates. Stainless steel (usually 304 grade) provides excellent corrosion resistance with less maintenance but has a slightly duller appearance. Painted finishes are the most economical and can be color-matched to your truck, but may need repainting every 5-7 years depending on exposure. For winter driOEMg or coastal areas, stainless steel typically offers the best long-term value.

How do I ensure proper fitment when ordering hoods, fenders, or bumpers?

Start by confirming your exact model year and checking whether you have a standard or extended hood configuration. Measure key mounting points on your current parts before ordering - bumper width should be either 18" or 20" depending on your model. For hoods and fenders, verify whether you have the single-headlight or dual-headlight configuration. When in doubt, provide your OEM number when ordering to ensure compatibility, as some mid-year production changes aren't reflected in standard model year listings.


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