SEARCH BY VEHICLE:
Enter Vehicle Year Make Model

Specify your vehicle's year, make and model to guarantee fit.

Year
Make
Model
Options
Drivetrain

2004 Peterbilt 378 Parts

What year is your
Free Same Day Shipping

2004 Peterbilt 378

Filter Results
  • Notify When Available
    Kit image

    Replaces 2004 Peterbilt 378 Driver & Passenger Side 2 Piece Manual Paint to Match West Coast Mirror Set TRQ MRA38850

    Brand: TRQ
    - MRA38850

    • Quantity: 2 Piece
    • Kit Includes: (1) Passenger Side Mirror
    • Kit Includes: (1) Driver Side Mirror
    • Adjustment Type: Manual
    • Mirror Type: West Coast
    • Mirror Color / Finish: Paint to Match
    $94.95
    Save 32%
    List $139.95 Save $45.00

    Guaranteed to Fit 2004 Peterbilt 378

    Guaranteed to Fit 2004 Peterbilt 378

    Replaces 2004 Peterbilt 378 Driver & Passenger Side 2 Piece Manual Paint to Match West Coast Mirror Set TRQ MRA38850

    Kit image
    Brand: TRQ - MRA38850
    • Quantity: 2 Piece
    • Kit Includes: (1) Passenger Side Mirror
    • Kit Includes: (1) Driver Side Mirror
    • Adjustment Type: Manual
    • Mirror Type: West Coast
    • Mirror Color / Finish: Paint to Match
    $94.95
    Save 32%
    List $139.95 Save $45.00

    Guaranteed to Fit 2004 Peterbilt 378

    Guaranteed to Fit 2004 Peterbilt 378

  • Notify When Available
    Exterior Door Handle

    Replaces 2004 Peterbilt 378 Front Driver Side Exterior Door Handle TRQ DHA45964

    Brand: TRQ
    - DHA45964

    • Color: Chrome
    $64.95
    Save 40%
    List $107.95 Save $43.00

    Guaranteed to Fit 2004 Peterbilt 378

    Guaranteed to Fit 2004 Peterbilt 378

    Replaces 2004 Peterbilt 378 Front Driver Side Exterior Door Handle TRQ DHA45964

    Exterior Door Handle
    Brand: TRQ - DHA45964
    • Color: Chrome
    $64.95
    Save 40%
    List $107.95 Save $43.00

    Guaranteed to Fit 2004 Peterbilt 378

    Guaranteed to Fit 2004 Peterbilt 378

  • Notify When Available
    Mirror

    Replaces 2004 Peterbilt 378 Driver Side Manual Heated Mirror TRQ MRA04137

    Brand: TRQ
    - MRA04137

    • Heated: Yes
    • Housing Turn Signal Indicator: Yes
    • Includes: Mounting Bracket
    • Design: Round
    • Cover Color: Stainless Steel
    • Cover Finish: Smooth
    • Housing Color: Stainless Steel
    • Adjustment Type: Manual
    • Mirror Turn Signal Indicator: Yes
    $46.95
    Save 37%
    List $74.95 Save $28.00

    Guaranteed to Fit 2004 Peterbilt 378

    Guaranteed to Fit 2004 Peterbilt 378

    Replaces 2004 Peterbilt 378 Driver Side Manual Heated Mirror TRQ MRA04137

    Mirror
    Brand: TRQ - MRA04137
    • Heated: Yes
    • Housing Turn Signal Indicator: Yes
    • Includes: Mounting Bracket
    • Design: Round
    • Cover Color: Stainless Steel
    • Cover Finish: Smooth
    • Housing Color: Stainless Steel
    • Adjustment Type: Manual
    • Mirror Turn Signal Indicator: Yes
    $46.95
    Save 37%
    List $74.95 Save $28.00

    Guaranteed to Fit 2004 Peterbilt 378

    Guaranteed to Fit 2004 Peterbilt 378

  • Notify When Available
    Mirror

    Replaces 2004 Peterbilt 378 Driver Side Manual Mirror TRQ MRA04135

    Brand: TRQ
    - MRA04135

    • Housing Turn Signal Indicator: Yes
    • Includes: Mounting Bracket
    • Design: Round
    • Cover Color: Stainless Steel
    • Cover Finish: Smooth
    • Housing Color: Stainless Steel
    • Adjustment Type: Manual
    • Heated: No
    • Mirror Turn Signal Indicator: Yes
    $44.95
    Save 38%
    List $71.95 Save $27.00

    Guaranteed to Fit 2004 Peterbilt 378

    Guaranteed to Fit 2004 Peterbilt 378

    Replaces 2004 Peterbilt 378 Driver Side Manual Mirror TRQ MRA04135

    Mirror
    Brand: TRQ - MRA04135
    • Housing Turn Signal Indicator: Yes
    • Includes: Mounting Bracket
    • Design: Round
    • Cover Color: Stainless Steel
    • Cover Finish: Smooth
    • Housing Color: Stainless Steel
    • Adjustment Type: Manual
    • Heated: No
    • Mirror Turn Signal Indicator: Yes
    $44.95
    Save 38%
    List $71.95 Save $27.00

    Guaranteed to Fit 2004 Peterbilt 378

    Guaranteed to Fit 2004 Peterbilt 378

  • Notify When Available
    Exterior Door Handle

    Replaces 2004 Peterbilt 378 Front Passenger Side Exterior Door Handle TRQ DHA45965

    Brand: TRQ
    - DHA45965

    • Color: Chrome
    $69.95
    Save 35%
    List $107.95 Save $38.00

    Guaranteed to Fit 2004 Peterbilt 378

    Guaranteed to Fit 2004 Peterbilt 378

    Replaces 2004 Peterbilt 378 Front Passenger Side Exterior Door Handle TRQ DHA45965

    Exterior Door Handle
    Brand: TRQ - DHA45965
    • Color: Chrome
    $69.95
    Save 35%
    List $107.95 Save $38.00

    Guaranteed to Fit 2004 Peterbilt 378

    Guaranteed to Fit 2004 Peterbilt 378

  • Notify When Available

    VIDEO

    Inner Tie Rod Tool

    Heavy Duty Inner Tie Rod Tool

    207 reviews
    Brand: TRQ
    - TLK01002

    • Socket Drive: 3/8 in. Drive
    • Product Grade: Heavy Duty
    $23.95
    Save 17%
    List $28.95 Save $5.00

    Heavy Duty Inner Tie Rod Tool

    VIDEO

    Inner Tie Rod Tool
    207 reviews
    Brand: TRQ - TLK01002
    • Socket Drive: 3/8 in. Drive
    • Product Grade: Heavy Duty
    $23.95
    Save 17%
    List $28.95 Save $5.00
  • Notify When Available
    Spark Plug Socket

    Spark Plug Socket

    13 reviews
    Brand: TRQ
    - TLK06456

    • Socket Drive: 3/8 in. Drive
    • Socket Size: 5/8 in
    $10.95
    Save 8%
    List $11.95 Save $1.00

    Spark Plug Socket

    Spark Plug Socket
    13 reviews
    Brand: TRQ - TLK06456
    • Socket Drive: 3/8 in. Drive
    • Socket Size: 5/8 in
    $10.95
    Save 8%
    List $11.95 Save $1.00
  • Notify When Available

    VIDEO

    Interior Trim Removal Kit

    Interior Trim Removal Kit

    96 reviews
    Brand: TRQ
    - TLK01001
    $39.95
    Save 20%
    List $49.95 Save $10.00

    Interior Trim Removal Kit

    VIDEO

    Interior Trim Removal Kit
    96 reviews
    Brand: TRQ - TLK01001
    $39.95
    Save 20%
    List $49.95 Save $10.00
  • Notify When Available

    VIDEO

    Disc Brake Pad Spreader

    Disc Brake Pad Spreader

    184 reviews
    Brand: TRQ
    - TLK01003

    $15.95
    Save 31%
    List $22.95 Save $7.00

    Disc Brake Pad Spreader

    VIDEO

    Disc Brake Pad Spreader
    184 reviews
    Brand: TRQ - TLK01003
    $15.95
    Save 31%
    List $22.95 Save $7.00
  • Notify When Available
    Disc Brake Service Kit

    Disc Brake Service Kit 50 State Formula

    57 reviews
    Brand: TRQ
    - KTA03112

    • Kit Includes: (1) Brake Caliper Hanger Hook Set
    • Kit Includes: (1) Disc Brake Pad Spreader Tool
    • Kit Includes: (1) Brake Cleaner & Fluid Kit
    $39.95
    Save 17%
    List $47.95 Save $8.00

    Disc Brake Service Kit 50 State Formula

    Disc Brake Service Kit
    57 reviews
    Brand: TRQ - KTA03112
    • Kit Includes: (1) Brake Caliper Hanger Hook Set
    • Kit Includes: (1) Disc Brake Pad Spreader Tool
    • Kit Includes: (1) Brake Cleaner & Fluid Kit
    $39.95
    Save 17%
    List $47.95 Save $8.00
1

...

4 5 6 7 8

...

15
Close



Peterbilt is a registered trademark of PACCAR Inc. 1A Auto is not affiliated with or sponsored by Peterbilt or PACCAR Inc. See all trademarks.
Same Day Shipping

Need your part faster? Choose expedited shipping at checkout.

Guaranteed To Fit

Highest quality, direct fit replacement auto parts enforced to the strictest product standards.

USA Customer Support

Exceeding customers' expectations, our team of passionate auto enthusiasts are here to help.

Instructional Video Library

Thousands of how-to auto repair videos to guide you step-by-step through your repair.

Go To Top
Enter Vehicle Year Make Model

Specify your vehicle's year, make and model to guarantee fit.

Year
Make
Model
Options
Drivetrain

This part doesn't fit a . Select from parts that fit.

Show parts that fit