We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Automotive

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is Synchromesh?

By Lori Kilchermann
Updated: May 23, 2024
Views: 31,723
Share

Synchromesh is a function of a transmission. The essence of synchromesh is to match the speed of an intended gear change to the speed of the current selected gear. By matching the speeds of the two gears, the gear change will be smooth and void of any grinding or noise. Prior to the advent of the synchromesh transmission, gear changes were very tricky and many people simply could not drive a stick-shift vehicle. The gears in a synchromesh-type transmission are always in motion and are activated or locked onto the shaft by a "dog collar."

In this type of transmission, the gears are always in motion when the vehicle is moving. In order to change gears, the synchromesh transmission uses linkages to slide the "dog collar" devices back and forth from one gear to another. When the dog collar meshes with a gear, it locks that gear to the transmission shaft, and the vehicle is then in that selected gear. As the dog collar leaves one gear, a special cone attached to the gear contacts the next gear, bringing it up to or down to the speed of the first gear. This allows the dog collar to slide easily into the next gear, thus meshing the gear and shaft together.

In early non-synchromesh transmissions, the gears were all separate and were best known as sliding mesh transmissions. In order to change gears in a non-synchromesh transmission, the shifting lever actually pulled one gear off of the drive shaft and slid or shifted another gear onto the shaft. This is where the term "shifting gears" comes from. The process was difficult at best, as the speed of the engine was required to match the speed of the desired gear and the operator used the gas pedal as much as the shifter when changing gears.

There is no need to double clutch a vehicle equipped with a synchromesh transmission. The act of double clutching was intended to bring the speed of the selected gear up to the same speed as the previous gear, thereby making the gear change effortless. The synchronized transmission does this for the driver by forcing the brass collar into the gear and allowing the dog collar to engage. The difference in the two styles of transmissions can best be compared by driving both the family vehicle and a riding mower. The auto can be shifted easily on the move, while the mower must stop to change gears.

Share
WikiMotors is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
By anon325931 — On Mar 19, 2013

Driving a manual is a delicate dance that takes many tries to get right, but once you master it you can dance all day and feel great.

By JaneAir — On Aug 29, 2011

I am very happy synchromesh transmissions were invented. I am one of those hapless souls that just can't drive a stick shift! Numerous people have tried to teach me, but no matter what they do I just don't get it.

In fact, I distinctly remember someone once trying to explain double clutching to me and totally not succeeding. I actually understand it a lot better after reading this article. But probably not well enough to actually drive a stick shift!

Share
https://www.wikimotors.org/what-is-synchromesh.htm
Copy this link
WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.

WikiMotors, in your inbox

Our latest articles, guides, and more, delivered daily.