Take the 2-minute tour ×
Motor Vehicle Maintenance & Repair Stack Exchange is a question and answer site for mechanics and DIY enthusiast owners of cars, trucks, and motorcycles. It's 100% free, no registration required.

When I got a manual transmission car (2003 Kia Rio) I noticed that it makes a winding sound in the reverse gear.

Here is an example video that I found that demonstrates the sound. http://www.youtube.com/watch?v=mi2t_VT6YWg

Why do manual transmission cars make this noise in reverse gear? Does it work differently than the forward gears?

share|improve this question

1 Answer 1

up vote 30 down vote accepted

In manual transmissions, the reverse gears use a different type of gear teeth than forward gears. Forward gears are helical gears, which have teeth that are pointed at an angle. When the gears rotate, most of the load is evenly spread due to the angles.

Reverse gears are cut into spurs, which don't absorb the load quite so well. As a result, there is more of a whining noise. The reason reverse gears are spurs is because reverse requires an idler gear to prevent accidentally shifting into reverse while moving. This is what is known as the gears not being synchronized, and this is also why you cannot shift into reverse when you're moving.

What you may find interesting is that my 1987 Ford F-150 4x4 makes this same sound when moving forward in low 1st gear. The 4 speed granny low first gear is also using this same technology as it's only designed for towing or going up or down really steep hills.

For more information on transmission gears, check out Why does my manual transmission car make a loud whirring noise in reverse?

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.
{"cc_re__cc_re__cc_by_sa_3_0": ["                  <li><a href=\"//area51.stackexchange.com\" title=\"proposing new sites in the Stack Exchange network\">Area 51</a></li>\r\n                        <li><a href=\"//careers.stackoverflow.com\">Stack Overflow Careers</a></li>\r\n                    \r\n                </ol>\r\n            </td>\r\n    </tr>\r\n</table>\r\n                </div>\r\n            </div>\r\n\r\n            <div id=\"copyright\">\r\n                site design / logo &#169; 2015 stack exchange inc; user contributions licensed under <a href=\"http://creativecommons.org/licenses/by-sa/3.0/\" rel=\"license\">cc by-sa 3.0</a> \r\n                with <a href=\"http://blog.stackoverflow.com/2009/06/attribution-required/\" rel=\"license\">attribution required</a>\r\n            </div>\r\n            <div id=\"svnrev\">\r\n                rev 2015.7.7.2698\r\n            </div>\r\n            \r\n        </div>\r\n    </div>\r\n    <noscript>\r\n        <div id=\"noscript-warning\">Motor Vehicle Maintenance &amp; Repair Stack Exchange works best with JavaScript enabled<img src=\"http://pixel.quantserve.com/pixel/p-c1rF4kxgLUzNc.gif"], "copyright__copyright__copyright": [" gear. The 4 speed granny low first gear is also using this same technology as it's only designed for towing or going up or down really steep hills.\n\nFor more information on transmission gears, check out Why does my manual transmission car make a loud whirring noise in reverse?\n\nshare|improve this answer\n\nYour Answer\n\n\u00a0\ndiscard\n\nBy posting your answer, you agree to the privacy policy and terms of service.\n\nNot the answer you're looking for? Browse other questions tagged or ask your own question."]}