2003 Peterbilt 378 Serpentine Belts
Save up to 40% on original replacement 2003 Peterbilt 378 Serpentine Belts. Navigate our online catalogue to find Serpentine Belts and other parts designed specifically to fit a 2003 Peterbilt 378.






Serpentine Belt - Air Conditioning
$45.75
$38.02
10+ In Stock
Ships: Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 14.9L 6Cyl L (-)(912) 5.39 137.0(Bore)6.65 169.0(Stroke);
Engine Base: 14.9L 6Cyl L (-)(912) 5.39 137.0(Bore)6.65 169.0(Stroke);





Serpentine Belt - Fan To Alternator
$86.37
$74.12
In Stock
Ships: Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0);
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0);
Vehicle Fitment Notes:
with 71-1/2in Long Belt
with 71-1/2in Long Belt





Serpentine Belt - Fan To Alternator
$86.37
$74.12
In Stock
Ships: Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 12.0L 732ci6 (5.10x5.90; 130.0x150.0);
Engine Base: 12.0L 732ci6 (5.10x5.90; 130.0x150.0);
Vehicle Fitment Notes:
with 71-1/2in Long Belt
with 71-1/2in Long Belt





Serpentine Belt - Fan To Alternator
$91.97
$74.79
Limited Stock
Ships: Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0);
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0);
Vehicle Fitment Notes:
with 73in Long Belt
with 73in Long Belt





Serpentine Belt - Fan To Alternator
$91.97
$74.79
Limited Stock
Ships: Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 12.0L 732ci6 (5.10x5.90; 130.0x150.0);
Engine Base: 12.0L 732ci6 (5.10x5.90; 130.0x150.0);
Vehicle Fitment Notes:
with 73in Long Belt
with 73in Long Belt





Serpentine Belt - Fan To Alternator
$101.32
$87.28
In Stock
Ships: Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0);
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0);
Vehicle Fitment Notes:
with 74in Long Belt
with 74in Long Belt





Serpentine Belt - Fan To Alternator
$101.32
$87.28
In Stock
Ships: Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Pick-Up: Ready in 1 Hour Monday Sep. 22nd
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 12.0L 732ci6 (5.10x5.90; 130.0x150.0);
Engine Base: 12.0L 732ci6 (5.10x5.90; 130.0x150.0);
Vehicle Fitment Notes:
with 74in Long Belt
with 74in Long Belt

Serpentine Belt - Alternator
$73.31
In Stock
Ships: Same or Next Business Day
Pick-Up: Same Business Day (Order before 12pm)
Pick-Up: Same Business Day (Order before 12pm)
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0); Engine Designation: C10; Engine Manufacturer: Caterpillar;
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0); Engine Designation: C10; Engine Manufacturer: Caterpillar;
Vehicle Fitment Notes:
w/ 70" Belt
w/ 70" Belt

Serpentine Belt - Alternator
$74.71
Limited Stock
Ships: Same or Next Business Day
Pick-Up: Same Business Day (Order before 12pm)
Pick-Up: Same Business Day (Order before 12pm)
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0); Engine Designation: C10; Engine Manufacturer: Caterpillar;
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0); Engine Designation: C10; Engine Manufacturer: Caterpillar;
Vehicle Fitment Notes:
w/ 71" Belt
w/ 71" Belt

Serpentine Belt - Alternator
$77.80
In Stock
Ships: in 3-4 Business Days
Pick-Up: in 3-4 Business Days
Pick-Up: in 3-4 Business Days
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0); Engine Designation: C10; Engine Manufacturer: Caterpillar;
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0); Engine Designation: C10; Engine Manufacturer: Caterpillar;
Vehicle Fitment Notes:
w/ 72 1/2" Belt
w/ 72 1/2" Belt

Serpentine Belt - Alternator
$81.11
In Stock
Ships: Same or Next Business Day
Pick-Up: Same Business Day (Order before 12pm)
Pick-Up: Same Business Day (Order before 12pm)
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0); Engine Designation: C10; Engine Manufacturer: Caterpillar;
Engine Base: 10.3L 10309cc 629ci L6 (4.9213x5.5118; 125.0x140.0); Engine Designation: C10; Engine Manufacturer: Caterpillar;
Vehicle Fitment Notes:
w/ 74" Belt
w/ 74" Belt

Serpentine Belt - Fan and Alternator
$81.11
In Stock
Ships: Same or Next Business Day
Pick-Up: Same Business Day (Order before 12pm)
Pick-Up: Same Business Day (Order before 12pm)
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Vehicle fitment:
Engine Base: 12.0L 732ci6 (5.10x5.90; 130.0x150.0); Engine Designation: C12; Engine Manufacturer: Caterpillar;
Engine Base: 12.0L 732ci6 (5.10x5.90; 130.0x150.0); Engine Designation: C12; Engine Manufacturer: Caterpillar;





Serpentine Belt - Fan and Alternator
$99.76
$82.70
Out of Stock
Condition: New
Required Per Vehicle: 1
Required Per Vehicle: 1
Made in Italy
Vehicle fitment:
Engine Base: 14.9L 6Cyl L (-)(912) 5.39 137.0(Bore)6.65 169.0(Stroke);
Engine Base: 14.9L 6Cyl L (-)(912) 5.39 137.0(Bore)6.65 169.0(Stroke);