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Peterbilt 388 Frame Crossmembers & Covers

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  • Qty in Cart
  • Quantity
  • Price
  • Subtotal
  • Brunner Custom Enclosed Light Bar W/ 8 - 4 In Rnd, 5 - 2 In Rnd LED Lights W/ Square Corners

    Brunner Custom Enclosed Light Bar W/ 8 - 4 In Rnd, 5 - 2 In Rnd LED Lights W/ Square Corners

    BRUNNER FABRICATION

    $1,783.99
    Rear Light Bar W/ 8 - 4 Inch Round & 5 - 2 Inch Round LED Lights By Brunner FabricationIf you are wanting to add lights to your cab, 4 State Trucks offers this high quality Brunner custom enclosed...
    09-021013
    SKU:
    09-021013
    Location:
    Made In USA
    Truck Class:
    Heavy Duty
    Make:
    Universal Items
    Finish Options:
    Polished
    Light Options:
    With Lights
    Material Options:
    Stainless Steel
    Product Type:
    Frame & Chassis
    $1,783.99
    Qty in Cart: 0
    Price:
    $1,783.99
    Subtotal:
  • Smooth Aluminum Wide Big Mount Step Box 18 Inch

    Smooth Aluminum Wide Big Mount Step Box 18 Inch

    ICONIC

    $729.99
    18 X 24 X 29.13 Inch Aluminum Big Mount Step Box* High Quality Big Mouth Step Box* Aluminum* Dimensions:  - 18.00 Inch Wide  - 24.00 Inch Height  - 29.13 Inch Depth* With Smooth Aluminum Lid * 50...
    09-020100537
    SKU:
    09-020100537
    Truck Class:
    Universal
    Width Options:
    18 Inch
    Material Options:
    Aluminum
    Make:
    Universal Items
    Finish Options:
    Smooth
    Product Type:
    Cargo Control
    Ready To Ship:
    Yes
    $729.99
    Qty in Cart: 0
    Price:
    $729.99
    Subtotal:
  • 22 Inch Smooth Aluminum Big Mouth Step Box W/ Lid

    22 Inch Smooth Aluminum Big Mouth Step Box W/ Lid

    ICONIC

    $759.99
    Big Mouth 22 X 24 Inch Smooth Aluminum Step Box* High Quality Step Box* Made Of Smooth Aluminum With Smooth Aluminum Lid* 22 Inch Wide* 24 Inch Height* 29.13 Inch Depth* Recommended 09-020100007...
    09-020100535
    SKU:
    09-020100535
    Truck Class:
    Universal
    Width Options:
    22 Inch
    Material Options:
    Aluminum
    Make:
    Universal Items
    Finish Options:
    Smooth
    Product Type:
    Cargo Control
    $759.99
    Qty in Cart: 0
    Price:
    $759.99
    Subtotal:
  • Diamond Plate Aluminum Step Saddle Box 36 x 25 x 28 Inch W/ Polished Side/Back Panels

    Diamond Plate Aluminum Step Saddle Box 36 x 25 x 28 Inch W/ Polished Side/Back Panels

    UNITED PACIFIC

    $902.99
    Aluminum Step Saddle Box W/ Locking Latch* High Quality Step Saddle Box* Made Of Aluminum* 36 Inch Length X 25 Inch Width X 28 Inch Height * Box Can Be Opened, Closed And Locked With Key* 2 Keys Are...
    09-020100534
    SKU:
    09-020100534
    Truck Class:
    Heavy Duty
    Make:
    Universal Items
    Material Options:
    Aluminum
    Finish Options:
    Diamond Plate
    Product Type:
    Cargo Control
    $902.99
    Qty in Cart: 0
    Price:
    $902.99
    Subtotal:
  • Diamond Plate Aluminum Step Saddle Box 18 x 25 x 28 Inch W/ Polished Back/Side Panels

    Diamond Plate Aluminum Step Saddle Box 18 x 25 x 28 Inch W/ Polished Back/Side Panels

    UNITED PACIFIC

    $618.99
    Aluminum Step Saddle Box With Lockable Door And Keys* High Quality Step Saddle Box * Made Of Aluminum* 18 Inch W X 25 Inch D X 28 Inch H * Box Can Be Opened* Closed And Locked With Key* 2 Keys Are...
    09-020100532
    SKU:
    09-020100532
    Truck Class:
    Heavy Duty
    Make:
    Universal Items
    Finish Options:
    Diamond Plate
    Material Options:
    Aluminum
    Product Type:
    Cargo Control
    $618.99
    Qty in Cart: 0
    Price:
    $618.99
    Subtotal:
  • Diamond Plate Aluminum Step Saddle Box 12 x 25 x 28 Inch W/ Polished Side/Back Panels

    Diamond Plate Aluminum Step Saddle Box 12 x 25 x 28 Inch W/ Polished Side/Back Panels

    UNITED PACIFIC

    $913.99
    Aluminum Step Saddle Box With Locking Door And 2 Keys* High Quality Step Saddle Box* 12 Inch L X 25 Inch W X 28 Inch * Aluminum Step* Box Can Be Opened, Closed And Locked With Key* 2 Keys Are...
    09-020100531
    SKU:
    09-020100531
    Truck Class:
    Heavy Duty
    Make:
    Universal Items
    Material Options:
    Aluminum
    Finish Options:
    Diamond Plate
    Product Type:
    Cargo Control
    $913.99
    Qty in Cart: 0
    Price:
    $913.99
    Subtotal:
  • Diamond Plate Aluminum Trailer Tongue Truck Box W/ Angled Front 18.5 X 15 X 49 Inch

    Diamond Plate Aluminum Trailer Tongue Truck Box W/ Angled Front 18.5 X 15 X 49 Inch

    BUYERS PRODUCTS

    $550.99
    18.5 X 15 X 49 Inch Diamond Plate Aluminum Trailer Tongue Truck Box W/ Angled FrontThis Diamond Tread Aluminum Trailer Tongue Truck Box is built tough to mount to A-frame style trailers. It keeps...
    09-020100518
    SKU:
    09-020100518
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Aluminum
    Product Type:
    Frame & Chassis
    $550.99
    Qty in Cart: 0
    Price:
    $550.99
    Subtotal:
  • Diamond Plate Aluminum Trailer Tongue Truck Box 15 X 14.5 X 34/22.5 Inch

    Diamond Plate Aluminum Trailer Tongue Truck Box 15 X 14.5 X 34/22.5 Inch

    BUYERS PRODUCTS

    $422.99
    15 X 14.5 X 34/22.5 Inch Diamond Plate Aluminum Trailer Tongue Truck BoxThis Diamond Tread Aluminum Trailer Tongue Truck Box is built for A-frame style trailers. It's tough yet lightweight with a...
    09-020100517
    SKU:
    09-020100517
    Truck Class:
    Universal
    Make:
    Universal Items
    Material Options:
    Aluminum
    Product Type:
    Frame & Chassis
    $422.99
    Qty in Cart: 0
    Price:
    $422.99
    Subtotal:
  • Black Steel Trailer Tongue Truck Tool Box 16.38 X 15 X 35.25/21.25 Inch

    Black Steel Trailer Tongue Truck Tool Box 16.38 X 15 X 35.25/21.25 Inch

    BUYERS PRODUCTS

    $411.99
    16.38 X 15 X 35.25/21.25 Inch Black Steel Trailer Tongue Truck Tool BoxAdd more storage to your A-Frame Trailer with this Black Steel Trailer Tongue Truck Tool Box. Its heavy-duty steel construction,...
    09-020100516
    SKU:
    09-020100516
    Truck Class:
    Universal
    Color:
    Black
    Width Options:
    35 Inch
    Material Options:
    Steel
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    $411.99
    Qty in Cart: 0
    Price:
    $411.99
    Subtotal:
  • Gloss Black Diamond Plate Aluminum Topside Truck Tool Box W/ Double Doors- 72 Inch

    Gloss Black Diamond Plate Aluminum Topside Truck Tool Box W/ Double Doors- 72 Inch

    AFTERMARKET

    $1,148.99
    72 Inch Gloss Black Diamond Plate Aluminum Topside Truck Tool Box W/ Double DoorsProtect your tools with the 72-Inch Gloss Black Diamond Plate Aluminum Topside Truck Tool Box with Double Doors...
    09-020100235
    SKU:
    09-020100235
    Color:
    Black
    Truck Class:
    Universal
    Height Options:
    17 Inch
    Width Options:
    13 Inch
    Length Options:
    72 Inch
    Material Options:
    Aluminum
    Make:
    Universal Items
    Finish Options:
    Diamond Plate
    Style Options:
    2 Door
    Product Type:
    Toolboxes
    $1,148.99
    Qty in Cart: 0
    Price:
    $1,148.99
    Subtotal:
  • Bright Diamond Plate Aluminum Topside Truck Tool Box W/ Double Doors- 72 Inch

    Bright Diamond Plate Aluminum Topside Truck Tool Box W/ Double Doors- 72 Inch

    AFTERMARKET

    $1,029.99
    72 Inch Bright Diamond Plate Aluminum Topside Truck Tool Box W/ Double DoorsKeep your tools organized and easily accessible with the 72 Inch Bright Diamond Plate Aluminum Topside Truck Tool Box with...
    09-020100234
    SKU:
    09-020100234
    Length Options:
    72 Inch
    Truck Class:
    Universal
    Height Options:
    17 Inch
    Width Options:
    13 Inch
    Material Options:
    Aluminum
    Make:
    Universal Items
    Finish Options:
    Diamond Plate
    Style Options:
    2 Door
    Product Type:
    Toolboxes
    $1,029.99
    Qty in Cart: 0
    Price:
    $1,029.99
    Subtotal:
  • Matte Black Diamond Plate Aluminum Deep Angled Crossover Tool Box- 69 Inch For Pickup Trucks

    Matte Black Diamond Plate Aluminum Deep Angled Crossover Tool Box- 69 Inch For Pickup Trucks

    AFTERMARKET

    $842.99
    69 Inch Matte Black Diamond Plate Aluminum Deep Angled Crossover Tool Box Fits Pickup TrucksProtect your tools and maximize truck bed space with the Matte Black Diamond Plate Aluminum Deep Angled...
    09-020100171
    SKU:
    09-020100171
    Width Options:
    20 Inch
    Length Options:
    69 Inch
    Color:
    Black
    Truck Class:
    Universal
    Material Options:
    Aluminum
    Make:
    Universal Items
    Finish Options:
    Diamond Plate
    Product Type:
    Toolboxes
    $842.99
    Qty in Cart: 0
    Price:
    $842.99
    Subtotal:
  • Bright Diamond Plate Aluminum Utility Chest Box- 48 Inch For Pickup Trucks

    Bright Diamond Plate Aluminum Utility Chest Box- 48 Inch For Pickup Trucks

    AFTERMARKET

    $648.99
    48 Inch Bright Diamond Plate Aluminum Utility Chest Box Fits Pickup TrucksKeep tools and equipment safe on the go with the 48-Inch Bright Diamond Plate Aluminum Utility Chest Box. Constructed from...
    09-020100060
    SKU:
    09-020100060
    Length Options:
    42 Inch
    Truck Class:
    Universal
    Width Options:
    24 Inch
    Material Options:
    Aluminum
    Make:
    Universal Items
    Finish Options:
    Diamond Plate
    Product Type:
    Toolboxes
    $648.99
    Qty in Cart: 0
    Price:
    $648.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Battery Hold-Down Kit For 2 Group 30 Or Group 31 Batteries

    Battery Hold-Down Kit For 2 Group 30 Or Group 31 Batteries

    MINIMIZER

    $88.99
    Battery Hold Down Kit With Bolts, Nuts, Washer Plates, J Hookds, Flat Washers, Battery Clamps & Locking Nuts* High Quality Battery Hold Down Kit* Vent Holes Are Required When Storing Batteries In The...
    09-020100005
    SKU:
    09-020100005
    Truck Class:
    Universal
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    $88.99
    Qty in Cart: 0
    Price:
    $88.99
    Subtotal:
  • Minimizer Poly In-Frame Tool Box- 33.5 X 13.5 X 22 Inch

    Minimizer Poly In-Frame Tool Box- 33.5 X 13.5 X 22 Inch

    MINIMIZER

    $864.99
    33.5 X 13.5 X 22 Inch Poly Composite Between-Frame Tool Box By MinimizerEnsure dry, secure storage on your truck with the Minimizer Poly In-Frame Tool Box. Constructed from durable poly composite,...
    09-020100004
    SKU:
    09-020100004
    Truck Class:
    Universal
    Make:
    Universal Items
    Product Type:
    Toolboxes
    $864.99
    Qty in Cart: 0
    Price:
    $864.99
    Subtotal:
  • Limited Quantity Available
    Smooth Aluminum Fairing Tool Box 18 X 20 X 18 Inch With Top Chest Diamond Plate Lid

    Smooth Aluminum Fairing Tool Box 18 X 20 X 18 Inch With Top Chest Diamond Plate Lid

    ICONIC

    $589.99
    Aluminum Fairing Tool Box With Top Chest & Diamond Plate Aluminum Lid* High Quality Fairing Tool Box* With Top Chest Diamond Plate Aluminum Lid* Smooth Aluminum Body * Hasp Latch * Dimensions  - 18...
    09-020100003
    SKU:
    09-020100003
    Length Options:
    18 Inch
    Truck Class:
    Universal
    Width Options:
    18 Inch
    Material Options:
    Aluminum
    Make:
    Universal Items
    Finish Options:
    Smooth
    Product Type:
    Cargo Control
    $589.99
    Qty in Cart: 0
    Price:
    $589.99
    Subtotal:
  • BESTfit Air Spring Replaces 8864, 1R12-1097, 66666, AB1DK23L-8864 For Kenworth AG400L Suspension

    BESTfit Air Spring Replaces 8864, 1R12-1097, 66666, AB1DK23L-8864 For Kenworth AG400L Suspension

    BESTFIT TRUCK PARTS

    $193.99
    BESTfit Air Spring For Kenworth AG400L Suspension* High Quality Air Spring* Rolling Lobe Type* Plastic Base* Without Bumper* 5600 Lb Load At 80 PSI* 7100 Lb Load At 100 PSI* 65 CPM Natural Frequency*...
    02-051032K01
    SKU:
    02-051032K01
    Height Options:
    25 Inch
    Truck Class:
    Heavy Duty
    Rating:
    100 PSI
    Diameter Options:
    12 Inch
    Style Options:
    Rolling Lobe
    Material Options:
    Plastic/Poly
    Make:
    Kenworth
    Product Type:
    Frame & Chassis
    $193.99
    Qty in Cart: 0
    Price:
    $193.99
    Subtotal:
  • Bendix Idler Pin Replaces 238888BXW For Peterbilt 386

    Bendix Idler Pin Replaces 238888BXW For Peterbilt 386

    OPP - ORIGINAL PARTS PROGRAM

    $15.60
    Bendix Idler Pin Fits Peterbilt 386* High Quality Idler Pin * Sold Individually* Warranty On Idler Pin Against Defects In Workmanship & Material From Date Of Purchase*|** This Is An OEM Replacement...
    01-151700001
    SKU:
    01-151700001
    Location:
    Made In USA
    Truck Class:
    Heavy Duty
    Material Options:
    Steel
    Make:
    Peterbilt
    Product Type:
    Interior
    $15.60
    Qty in Cart: 0
    Price:
    $15.60
    Subtotal:
  • FREE SHIPPING OVER $249
    BESTfit 8.04 Inch OAL Air Spring Stud Replaces 27-01746 For Peterbilt New Low Air Leaf Suspension

    BESTfit 8.04 Inch OAL Air Spring Stud Replaces 27-01746 For Peterbilt New Low Air Leaf Suspension

    BESTFIT TRUCK PARTS

    $9.35
    BESTfit Air Spring Stud Fits Peterbilt New Low Air Leaf SuspensionThe BESTfit 8.04 Inch Overall Length Air Spring Stud is a premium replacement component designed to perfectly match OEM part number...
    01-051054K01
    SKU:
    01-051054K01
    Diameter Options:
    1/2 Inch
    Length Options:
    8 Inch
    Truck Class:
    Heavy Duty
    Make:
    Peterbilt
    Product Type:
    Frame & Chassis
    $9.35
    Qty in Cart: 0
    Price:
    $9.35
    Subtotal:
  • FREE SHIPPING OVER $249
    BESTfit U-Bolt Kit 13.5 Inch For Peterbilt W/ Flex Air Suspensions

    BESTfit U-Bolt Kit 13.5 Inch For Peterbilt W/ Flex Air Suspensions

    BESTFIT TRUCK PARTS

    $65.99
    13.5 Inch U-Bolt Kit By BESTfit Fits Peterbilt W/ Flex Air SuspensionsThe BESTfit 0.875 x 5.125 x 13.5 Inch U-Bolt Kit is a heavy-duty replacement designed to provide secure fastening for truck...
    01-051047K01
    SKU:
    01-051047K01
    Truck Class:
    Heavy Duty
    Make:
    Peterbilt
    Product Type:
    Frame & Chassis
    Position:
    Kit Full
    Diameter Options:
    7/8 Inch
    Width Options:
    5 1/8 Inch
    Material Options:
    Steel
    Length Options:
    13 1/2 Inch
    $65.99
    Qty in Cart: 0
    Price:
    $65.99
    Subtotal:
  • Total: items /

Adding your products to cart

Enhance your Peterbilt 388 with durable Peterbilt 377, 378, 388, and 389 frame crossmembers and stylish covers. From stainless steel and aluminum options to fiberglass and steel designs, this product lineup offers a variety of high-quality products to protect your truck's rear frame. Keep your rig looking its best with customizable covers that feature notch cutouts, light openings, and emblem mounts. Plus, find the right walking beam components to ensure a smooth, comfortable ride. Whether you're restoring a classic Peterbilt or upgrading a newer model, this collection of frame crossmembers and covers has everything you need to elevate your Peterbilt 388's appearance and functionality.

Frequently Asked Questions About Peterbilt 388 Frame Crossmembers & Covers

What are frame crossmembers and covers used for on a Peterbilt 388?

Frame crossmembers are structural components that run horizontally between the frame rails, providing rigidity and support for the chassis, while covers protect these areas from road debris, moisture, and corrosion. Together they help maintain frame integrity and give the underside of the truck a cleaner, finished appearance.

Will these crossmembers and covers fit my specific Peterbilt 388 configuration?

Fitment can vary depending on wheelbase, frame rail spacing, and whether your truck has factory or aftermarket modifications. It is important to check the listed specifications and, when possible, compare part numbers with your truck's build sheet or consult with our parts team before ordering to confirm a proper fit.

What materials are these parts made from, and how well do they hold up over time?

Most crossmembers and covers are constructed from steel or aluminum, depending on the specific part and application. Steel components typically offer strength and durability for structural crossmembers, while aluminum covers are often chosen for their corrosion resistance and lighter weight. Finish options may include raw metal, painted, or powder-coated surfaces to help resist rust and wear from daily use.

Can I install a crossmember or cover myself, or should I have a professional do it?

Covers are generally straightforward to install with basic tools and can often be handled by anyone comfortable with routine truck maintenance. Structural crossmembers, however, are load-bearing components, and improper installation can affect frame integrity and safety. For crossmember replacement or modification, we recommend having the work done by a qualified technician familiar with frame repairs.

How do I know if my current crossmember or cover needs to be replaced?

Common signs include visible rust or corrosion, cracks, bending, loose or missing mounting hardware, or a cover that no longer sits flush and allows debris underneath. If you notice any flexing or unusual noise from the frame area while driving, it is a good idea to have the crossmember inspected as soon as possible.


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