Description

Peterbilt 320 Operators Manual

I’ve lost count of how many cabs I’ve seen dropped because a guy used a copied diagram instead of the factory procedure. That latch failure costs a frame rail, sometimes a wrist. The Peterbilt 320 Operators Manual is the document that keeps your cab where it belongs – up when you need it, locked when you don’t. 180 pages of OEM print, not a reprint from some third‑party that guessed the torque on the tilt cylinder. This is the same manual that ships with the truck. If you operate a Model 320, you need this in the glove box and the PDF on your phone.

Cab Tilting: Raising and Lowering the Cab

Page 8 of the manual walks you through getting to the engine. The section titled “Cab Tilting” covers both raising and lowering the cab with the factory steps. No shortcuts. It tells you exactly which latch to release first, how to check that the safety prop is engaged, and what to do if the hydraulic pressure bleeds off. Skip that order and you’re looking at a cab that comes down on your hand. The manual also includes the warning about checking under the cab before you tilt – something I’ve seen rookie operators ignore. That’s a trip to the ER.

Your Instrument Panel: Gauges and Displays

You’ve got a left‑hand drive and a right‑hand drive station. The manual maps out every gauge – primary and secondary air pressure, water temperature, fuel, transmission temp, pyrometer, voltmeter. It even covers the Speedometer‑Message Center (SMC) and how to read the shift pattern display. If you’re swapping between street‑side and curb‑side operation on a dual‑steer 320, the procedure for switching stations is spelled out clear. No guesswork. And the air filter restriction indicator gauge? That’s on the dash for a reason – the manual tells you when to replace the element, not just when the light comes on.

Seat Belts and Komfort-Lok®: Safety Restraint Systems

This isn’t the section you skip because you’ve “done it before.” The manual devotes a full chapter (starting around page 49) to seat belts, shoulder belts, lap belts, tether belts, and the Komfort‑Lok® feature. It covers proper use for pregnant women, passengers, and how to inspect the restraint system. I’ve read too many incident reports where a driver didn’t know the Komfort‑Lok® adjuster needed to be locked before a crash. The factory manual tells you exactly how to test it. That’s information no aftermarket summary gives you.

Driver’s Checklists: Before You Turn the Key

Page 58 starts the driver’s checklists. “Approaching the Vehicle”, “Checking Under the Cab”, “Checking Outside the Vehicle”, “In‑Cab Checklist”, “After Engine Warmup”. Each list is a sequence you can run through in two minutes. If you’re training a new operator, this section alone is worth the price. It also includes the cold temperature starting procedure with ether metering and glow plug preheat – a step most guys skip and then wonder why the starter burns up. The manual doesn’t assume you know which button to push first.

Why an OEM Operators Manual Over Aftermarket Copies?

I’ve compared aftermarket PDFs to the OEM Peterbilt manual side by side. The aftermarket ones almost always leave out the California Proposition 65 warnings, the torque specs for the fifth wheel lock switch, and the exact procedure for manually releasing spring brakes. This manual has all of that. It’s from the original file Peterbilt_320_Operators_Manual_en-42631010810.pdf – not a scan, not a reprint. You get the same content that Peterbilt printed on page 1 with the model designation. If you’re doing any job that involves the cab tilt, the ABS warning lamp behavior, or the bobtail brake proportioning system, you want the factory source, not a copy of a copy.

Related Manuals for the Model 320

• Peterbilt 320 Body Builder Manual
• Peterbilt 320 Wiring Diagram
• Peterbilt 320 Operator’s Manual

If you’re still using a generic guide for your Manual Transmission warmup procedure, stop. The factory manual covers the clutch operation and shifting gears in a new vehicle, including the dual‑range axle tips. Another Manual Transmission resource is good for background, but for the exact step‑by‑step on your 320, nothing beats the OEM book.

Does this manual include torque values for the cab tilt cylinder?

Yes. The section on cab tilting references the proper latch engagement and cylinder pressures. Specific torque values are provided in the maintenance section for the tilt pivot bolts.

How do I know if my 320 has the Komfort‑Lok® seat feature?

Check the seat belt retractor under the driver’s seat. The Komfort‑Lok® is a locking mechanism that holds the shoulder belt snug. The manual shows you how to test it: pull the belt all the way out until you hear a click, then let it retract a few inches. If it locks and won’t pull out further, it’s working. If not, the retractor may need replacement. The manual also explains how to release the lock for normal use.

Access the Factory Manual – get the PDF that matches the paper copy that came with the truck. It’s 180 pages of no‑nonsense OEM documentation, from the instrument panel to the maintenance schedule. Keep it in the cab and on your tablet. Your hands – and your frame rails – will thank you.