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Peterbilt 388 Frame Crossmembers & Covers

  • Product
  • Qty in Cart
  • Quantity
  • Price
  • Subtotal
  • Auxiliary Spring Hendrickson/ Aux Replaces E-14896, 67778, 67778-000

    Auxiliary Spring Hendrickson/ Aux Replaces E-14896, 67778, 67778-000

    AFTERMARKET

    $172.99
    Ds Auxiliary Spring Hendrickson/ Aux* High Quality Auxiliary Spring* Height- 4.218 Inch* Made In USA* Sold Individually* Warranty On Auxiliary Springs Against Defects In Workmanship & Material From...
    29-05100124
    SKU:
    29-05100124
    Truck Class:
    Heavy Duty
    Product Type:
    Frame & Chassis
    Height Options:
    4 Inch
    Make:
    Universal Items
    $172.99
    Qty in Cart: 0
    Price:
    $172.99
    Subtotal:
  • U-Bolt Plate 3-1/2 Inch Replaces R309613

    U-Bolt Plate 3-1/2 Inch Replaces R309613

    AUTOMANN USA

    $8.09
    U-Bolt Plate 3-1/2 Inch* High Quality U-Bolt Plate* Dimensions:  - C To C- 3.50 Inch  - Thickness- 0.50 Inch  - 2 Holes- 0.685 Inch* 2 Holes- 0.685 Inch* Sold Individually* Warranty On U-Bolt Plates...
    29-05090041
    SKU:
    29-05090041
    Length Options:
    3 Inch
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Make:
    Universal Items
    $8.09
    Qty in Cart: 0
    Price:
    $8.09
    Subtotal:
  • Spring Riser-Spacer Block 6 X 3 X 1.5 Inch With 0.77 Inch Hole Underneath

    Spring Riser-Spacer Block 6 X 3 X 1.5 Inch With 0.77 Inch Hole Underneath

    AFTERMARKET

    $53.99
    1.5 Inch Lift Block- Spacer Plate For 3 Inch Springs* High Quality Spring Riser Block* Dimensions:   - Length- 6.00 Inch  - Width- 3.00 Inch  - Height- 1.50 Inch  - Hole Underneath- 0.77 Inch* Made...
    09-05090020
    SKU:
    09-05090020
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Length Options:
    6 Inch
    Width Options:
    3 Inch
    Height Options:
    1 1/2 Inch
    Make:
    Universal Items
    $53.99
    Qty in Cart: 0
    Price:
    $53.99
    Subtotal:
  • Spring Riser-Spacer Block 6 X 3 X 2-3/8 Inch With 3/4 Inch Center Post, 0.77 Inch Hole Underneath

    Spring Riser-Spacer Block 6 X 3 X 2-3/8 Inch With 3/4 Inch Center Post, 0.77 Inch Hole Underneath

    AFTERMARKET

    $91.99
    2 3/8 Inch Lift Block- Spacer Plate For 3 Inch SpringsMaintain truck stability and performance with this Spring Riser-Spacer Block, designed to reinforce and elevate leaf springs for heavy-duty...
    09-05090022
    SKU:
    09-05090022
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Width Options:
    3 Inch
    Length Options:
    6 Inch
    Make:
    Universal Items
    $91.99
    Qty in Cart: 0
    Price:
    $91.99
    Subtotal:
  • Spring Riser-Spacer Block 7 X 2.5 X 1 Inch W/ 5/8 Inch Center Post

    Spring Riser-Spacer Block 7 X 2.5 X 1 Inch W/ 5/8 Inch Center Post

    AUTOMANN USA

    $20.81
    1 Inch Lift Block- Spacer Plate For 2.5 Inch Springs* High Quality Spring Riser Block* Dimensions:  - 7.0In Lg.  - 2-1/2In Wd.   - 1.0In Thk* With 5/8In Center Post* Sold Individually* Warranty On...
    09-05090058
    SKU:
    09-05090058
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Width Options:
    2 Inch
    Length Options:
    7 Inch
    Make:
    Universal Items
    $20.81
    Qty in Cart: 0
    Price:
    $20.81
    Subtotal:
  • Spring Riser-Spacer Block 7 X 3 X 1 Inch With 9/16 Inch Center Post

    Spring Riser-Spacer Block 7 X 3 X 1 Inch With 9/16 Inch Center Post

    BESTFIT TRUCK PARTS

    $28.10
    Leveling Lift Block* High Quality Spring Riser Block* Dimensions:  - 7.0 Inch Length   - 3.00 Inch Width  - 1.0 Inch Thick* With 9/16 Inch Center Post* Sold Individually* Warranty On Spring Riser...
    09-05090015
    SKU:
    09-05090015
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Width Options:
    3/4 Inch
    Length Options:
    7 Inch
    Make:
    Universal Items
    $28.10
    Qty in Cart: 0
    Price:
    $28.10
    Subtotal:
  • Spring Riser-Spacer Block 6 X 3 X 1 Inch With 1.79 Inch Hole Underneath

    Spring Riser-Spacer Block 6 X 3 X 1 Inch With 1.79 Inch Hole Underneath

    AUTOMANN USA

    $27.20
    1 Inch Lift Block- Spacer Plate For 3 Inch Springs* High Quality Spring Riser Block* Dimensions:  - Length- 6.00 Inch  - Width- 3.00 Inch  - Height- 1.00 Inch  - Hole Underneath- 0.79 Inch* Sold...
    09-05090019
    SKU:
    09-05090019
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Width Options:
    3 Inch
    Length Options:
    6 Inch
    Height Options:
    1 Inch
    Make:
    Universal Items
    $27.20
    Qty in Cart: 0
    Price:
    $27.20
    Subtotal:
  • Spring Riser-Spacer Block 7 X 3 X 1 Inch With 3/4 Inch Center Post

    Spring Riser-Spacer Block 7 X 3 X 1 Inch With 3/4 Inch Center Post

    BESTFIT TRUCK PARTS

    $37.10
    Leveling Lift Block* High Quality Spring Riser Block* Dimensions:  - 7.0 Inch Length   - 3.00 Inch Width  - 1.0 Inch Thick* With 3/4 Inch Center Post* Sold Individually* Warranty On Spring Riser...
    09-05090016
    SKU:
    09-05090016
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Width Options:
    3 Inch
    Length Options:
    7 Inch
    Make:
    Universal Items
    $37.10
    Qty in Cart: 0
    Price:
    $37.10
    Subtotal:
  • Round U-Bolt Kit 7/8 X 3 X 16.5 Inch

    Round U-Bolt Kit 7/8 X 3 X 16.5 Inch

    AFTERMARKET

    $85.99
    7/8 X 3 X 16.5 Inch Round U-Bolt Kit* High Quality U-Bolt Kit* Kit Includes:  - (2) U Bolts (Round Bend)  - Grade 5  - 16.50 Inch Overall Length  - 6.00 Inch Of 7/8 Inch - 14 Thread  - 3.00 Inch...
    29-05100352
    SKU:
    29-05100352
    Truck Class:
    Heavy Duty
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    Width Options:
    3 Inch
    Length Options:
    16 1/2 Inch
    Material Options:
    Steel
    $85.99
    Qty in Cart: 0
    Price:
    $85.99
    Subtotal:
  • Side Bar Advance Mixer Replaces 4006002, 1138109, 13131 For Advance Mixer

    Side Bar Advance Mixer Replaces 4006002, 1138109, 13131 For Advance Mixer

    BESTFIT TRUCK PARTS

    $30.34
    Advance Mixer Side Bar* High Quality Side Bar* Dimensions:  - Length- 5.344 Inch  - Width- 2.00 Inch  - C To C- 3.313 Inch  - Height- 1.00 Inch* With Ears* Side Bar Type- 12* Hole Size- 1.125 Inch*...
    80-05090010
    SKU:
    80-05090010
    Truck Class:
    Heavy Duty
    Product Type:
    Frame & Chassis
    Length Options:
    5 Inch
    Width Options:
    2 Inch
    Make:
    Universal Items
    $30.34
    Qty in Cart: 0
    Price:
    $30.34
    Subtotal:
  • 3/8 X 1-1/4 Inch SS Bolt Kit

    3/8 X 1-1/4 Inch SS Bolt Kit

    4 STATE TRUCKS

    $4.17
    Bolt Kit - SS 3/8 X 1-1/4 Inch* High Quality Bolt Kit* Stainless Steel * 3/8 X 1-1/4 Inch* Sold As Kit* Warranty On Bolt Kits Against Defects In Workmanship & Material From Date Of Purchase*** High...
    09-05250009
    SKU:
    09-05250009
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    $4.17
    Qty in Cart: 0
    Price:
    $4.17
    Subtotal:
  • 3/8 X 1 Inch SS Bolt Kit

    3/8 X 1 Inch SS Bolt Kit

    4 STATE TRUCKS

    $4.58
    Bolt Kit - SS 3/8 X 1 Inch* High Quality Bolt Kit* Stainless Steel * 3/8 X 1 Inch* Sold As Kit* Warranty On Bolt Kits Against Defects In Workmanship & Material From Date Of Purchase*** High Quality...
    09-05250008
    SKU:
    09-05250008
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    $4.58
    Qty in Cart: 0
    Price:
    $4.58
    Subtotal:
  • BESTfit Spring Riser-Spacer Block 7 X 4 X 1 Inch With 3/4 Inch Center Post

    BESTfit Spring Riser-Spacer Block 7 X 4 X 1 Inch With 3/4 Inch Center Post

    BESTFIT TRUCK PARTS

    $34.85
    1 Inch Lift Block- Spacer Plate For 4 Inch Springs By BESTfitStrengthen your truck's suspension system with the BESTfit Spring Riser-Spacer Block. Featuring a 7 x 4 x 1-inch profile and 3/4-inch...
    09-05090017
    SKU:
    09-05090017
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Length Options:
    7 Inch
    Width Options:
    4 Inch
    Diameter Options:
    1 Inch
    Make:
    Universal Items
    $34.85
    Qty in Cart: 0
    Price:
    $34.85
    Subtotal:
  • Poly Fontaine Fifth Wheel Bracket Liner Kit

    Poly Fontaine Fifth Wheel Bracket Liner Kit

    AFTERMARKET

    $70.99
    Fontaine Fifth Wheel Bracket Liner KitAchieve smoother fifth wheel operation with the Poly Fontaine Fifth Wheel Bracket Liner Kit, designed for durability and precision. The kit includes a poly...
    19-05110006
    SKU:
    19-05110006
    Truck Class:
    Heavy Duty
    Material Options:
    Plastic/Poly
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    $70.99
    Qty in Cart: 0
    Price:
    $70.99
    Subtotal:
  • Fontaine Fifth Wheel Slider Bracket 16 Inch

    Fontaine Fifth Wheel Slider Bracket 16 Inch

    OPP - ORIGINAL PARTS PROGRAM

    $1,098.99
    Replacement 5th Wheel Air Slider Rail* High Quality Slide Rail* Dimensions:  - 16 Inch Slide Travel   - 46 Inch Overall Length * Made In USA* Sold Individually* Warranty On Slide Rails Against...
    09-0511072
    SKU:
    09-0511072
    Height Options:
    16 Inch
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Length Options:
    46 Inch
    Make:
    Universal Items
    $1,098.99
    Qty in Cart: 0
    Price:
    $1,098.99
    Subtotal:
  • Fontaine Fifth Wheel Slider Bracket 10 3/4 Inch

    Fontaine Fifth Wheel Slider Bracket 10 3/4 Inch

    OPP - ORIGINAL PARTS PROGRAM

    $2,139.99
    Slider Bracket For Fontain 6000 7000 7000CC 5th Wheel Top Plate* High Quality Air Slide Bracket* 10 3/4 Inch Mounted Height* Bracket Comes Assembled* Height Measured From Top Of Truck Frame To Top Of...
    09-0511069
    SKU:
    09-0511069
    Product Type:
    Frame & Chassis
    Truck Class:
    Heavy Duty
    Height Options:
    10 Inch
    Make:
    Universal Items
    $2,139.99
    Qty in Cart: 0
    Price:
    $2,139.99
    Subtotal:
  • Fifth Wheel Cast Steel Top Plate 50,000 lbs Vertical Load Driver Side FON SLTPL6000

    Fifth Wheel Cast Steel Top Plate 50,000 lbs Vertical Load Driver Side FON SLTPL6000

    OPP - ORIGINAL PARTS PROGRAM

    $1,787.99
    Replacement Fifth Wheel Cast Steel Top Plate* High Quality Top Plate* Cast Steel * 55,000 Vertical Load* 150,000 Drawbar Pull (No-Slack Lock)* Sold Individually* Warranty On Top Plates Against...
    09-05110082
    SKU:
    09-05110082
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    $1,787.99
    Qty in Cart: 0
    Price:
    $1,787.99
    Subtotal:
  • Fifth Wheel Stamped Steel Top Plate 50,000 lbs Vertical Load Driver Side FON SLTPL6000

    Fifth Wheel Stamped Steel Top Plate 50,000 lbs Vertical Load Driver Side FON SLTPL6000

    OPP - ORIGINAL PARTS PROGRAM

    $1,609.99
    Replacement Fifth Wheel Stamped Steel Top Plate* High Quality Top Plate* Stamped Steel* 50,000 Vertical Load* 150,000 Drawbar Pull (No-Slack Lock)* Sold Individually* Warranty On Top Plates Against...
    09-05110081
    SKU:
    09-05110081
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    $1,609.99
    Qty in Cart: 0
    Price:
    $1,609.99
    Subtotal:
  • Fontaine Fifth Wheel Slider Rail 36 Inch For AWB, AWS & MWS

    Fontaine Fifth Wheel Slider Rail 36 Inch For AWB, AWS & MWS

    OPP - ORIGINAL PARTS PROGRAM

    $1,364.99
    Replacement 5th Wheel Air Slider Rail* High Quality Fifth Wheel Slider Wall* Dimensions:  - 36 Inch Slide Travel  - 66 Inch Overall Length* Made In USA* Sold Individually* Warranty On Slider Walls...
    09-0511067
    SKU:
    09-0511067
    Truck Class:
    Heavy Duty
    Length Options:
    66 Inch
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    $1,364.99
    Qty in Cart: 0
    Price:
    $1,364.99
    Subtotal:
  • Black Fontaine Fifth Wheel Cover

    Black Fontaine Fifth Wheel Cover

    WTI FENDERS

    $258.54
    Fontaine Fifth Wheel Cover* High Quality Fifth Wheel Covers* Made Of Fiberglass* Made In USA* Sold Individually* Warranty On Fifth Wheel Covers Against Defects In Workmanship & Material From Date Of...
    09-05110077
    SKU:
    09-05110077
    Product Type:
    Frame & Chassis
    Make:
    Universal Items
    $258.54
    Qty in Cart: 0
    Price:
    $258.54
    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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