Timing Belt Identification Guide

In a variety of applications, rubber timing belts serve a critical purpose: synchronizing movement in a pulley system. One of the most common applications of the timing belt is within vehicle engines, synchronizing action between the camshaft and crankshaft.

Within an automobile, a properly functioning timing belt is absolutely critical – in fact, a failed timing belt could leave you stranded. A broken timing belt can cause further damage to valves, pistons, or other engine components. Read more about How to Know When to Replace Your Timing Belt here.

Identifying timing belts is crucial to their maintenance, and there are several ways to do so. Read on for our beginner’s guide to identifying timing belts.

1. Identify the Timing Belt by Manufacturer Name:

Often, the timing belt you are seeking to identify will feature both A) a part number, and B) the name of the timing belt manufacturer. The manufacturer's name should ideally be printed on the timing belt. However, in certain circumstances, you may find the print is no longer legible, or that printing its name on the timing belt was not the standard practice of the manufacturer. Below is a list of common manufacturers you may see on your timing belt:

Bando
Brecoflex
Carlisle Power Transmission Products
Continental ContiTech
Elatech
FN Sheppard
Forbo Siegling
Gates
Goodyear Engineered Products (Veyance)
Habasit
Jason
Mectrol (Gates)
Megadyne
Mitsuboshi Belting, Ltd.
Optibelt Power Transmission
U.S.A. Drives, Inc.

2. Identify the Timing Belt by its Letter and Number Combination:

Sometimes, manufacturers will leave behind a combination of numbers and letters that only they would be able to easily identify. While a letter/number combination is not easy to reference, the numbers and/or letters represent a standard trade size. The number is key to identifying your belt’s specifics. The number and letter combination will look generally like “640-8MX-12,” for example, although your letters and numbers may differ.

If you didn’t see a complete or legible marking, or any marking at all, on your timing belt, check the timing pulley. Some manufacturers will mark the pulley rather than the timing belt itself. (More information on what to do with this number and letter combination, if you have it, further down in this article!)

3. Manually Identify the Timing Belt Through Another Method:

If there has not been a manufacturer name, nor a number or number and letter combination printed on the timing belt, you may be able to identify the timing belt manually through the following method:

Measuring the Timing Belt’s Width, Length, and Pitch:

You will need to take measurements of the timing belt’s width, length, and pitch to identify it if you don’t have a printed manufacturer name or letter and number combination.

How to measure a timing belt’s pitch: The pitch is defined as the distance, in inches and/or millimeters (mm) from the center of the top of one of the ridges or teeth of the timing belt and the center of the top of the nearest ridge or tooth. In short, the timing belt’s pitch is the length from the top of one ridge to the top of the next ridge. Ridges commonly come in many different shapes, or “profiles,” including 3mm, 5mm, 8mm, and 14mm pitches. It’s not always easy to measure this small of a distance. You may need a special tool to measure the pitch.

If you have been able to measure the pitch and ridge profile of your timing belt, you’ll be able to use these numbers to identify it based on its timing belt standard size.

You will also need to know the material of your timing belt. Your timing belt is most likely made of neoprene or polyurethane. If your timing belt is made of neoprene, it will feel rubbery, flexible, and may flake apart with overuse. Neoprene is usually black and bends easily. If your timing belt is made of polyurethane, it will likely appear smooth and slick. Polyurethane is less flexible than neoprene. The easiest way to tell the difference between neoprene and polyurethane is that polyurethane timing belts are clear or white, while neoprene timing belts are typically black.

How to Create and Interpret Your Timing Belt Number:

Recall that the number and letter combination will look generally like “640-8MX-12,” for example, although your letters and numbers may differ. To create your timing belt number if you don’t have it, or to interpret it if you do, we’ll break down this example number into its three parts:

1. The first group of numbers in your timing belt number represents the length of your timing belt’s pitch by millimeters. The number you see is the number of millimeters of the pitch’s length. In our example, the length of the pitch of the timing belt would be 640 millimeters, for instance. In standard sizing, the length will be in inches. For example, 168XL050, the 168 would mean 16.8” long. If you had to measure your pitch, you’ve already completed the first step to recreating your timing’s belts number for its identification.

2. The next grouping may actually be a combination of numbers and letters. This group identifies your timing belt’s “ridge profile,” which we discussed above.

You will likely see one of the following profile combinations:

XL (.200")
L (.375")
MXL (.080")
H (.500")
HTD (3mm, 5mm, and 8mm)
Powerhouse™ (2mm, 3mm, 5mm, 8mm, and 14mm)
T2.5, T5, T10, AT5, AT10
Powerhouse MX™ (8mm and 14mm)

3. The last grouping of numbers identifies the width of your timing belt. In metric sizing, the number represents the width of the timing belt in millimeters. In standard sizing, the number represents inches, though for sizes less of less than an inch, the number will start with a zero to reflect it. For example:

012=0.125", 025=0.25", 037=0.375", 050=0.500", 075=0.75", 100=1.00", 150=1.50", 200=2.00", and 300=3.00".

Do you have another letter at the end of your number and letter combination? This represents the material used to make the timing belt. If you see a “G,” for example, your timing belt was made of neoprene reinforced with fiberglass; if you see a “UP,” your timing belt was made of urethane reinforced with polyester; if you see a “UK,” your timing belt was made with urethane reinforced with Kevlar; and if you see a “US,” your timing belt was made of urethane reinforced with steel.

Illinois Pulley & Gear: Timing Belt Pulley Manufacturers

At Illinois Pulley & Gear, we are passionate about producing high-quality timing belt pulley systems that are built to last. Every timing belt pulley is made-to-order to customer specifications, depending on your precise need.

We are client-oriented and ready to listen. To inquire about timing belt pulley systems today, reach out via our online contact form or give us a call at 847.407.9595.