Editing Constant-velocity joint (section)

== Usage in cars ==
Early [[front-wheel drive]] vehicles (such as the 1930s [[Citroen Traction Avant]]) and the front axles of [[off-road vehicle|off-road]] four-wheel drive vehicles used universal joints rather than CV joints. Amongst the first cars to use CV joints were the 1926 [[Tracta]], the 1931 [[DKW F1]] and the 1932 [[Adler Trumpf]], all of which were front-wheel drive and used the Tracta joint design under licence.<ref name=patent>{{cite journal |url=http://v3.espacenet.com/origdoc?DB=EPODOC&IDX=US1665280&F=0&QPN=US1665280|author=Rzeppa, Alfred H. |journal= US patent|title=Universal Joint |version=no. 1,665,280 |year=1927}}</ref><ref>{{cite web |url=http://v3.espacenet.com/publicationDetails/originalDocument?CC=FR&NR=628309A&KC=A&FT=D&date=19271021&DB=EPODOC&locale=fr_V3 |title=European Patent FR628309}}</ref> The CV joints allowed a smooth transfer of power over a wider range of operating angles (such as when the suspension is compressed by cornering force or a bump in the road).

Modern [[rear-wheel drive]] cars with [[independent rear suspension]] typically use CV joints at the ends of the [[Axle#Drive axle|half-shafts]] and increasingly use them on the [[Drive shaft#Front-engine, rear-wheel drive|tailshaft]].{{citation needed|date=February 2023}}

=== CV boots and lubrication ===
A separate flexible cover is usually installed over the CV joint, to protect it from foreign particles and prevent the lubricating grease from leaking out.<ref>{{cite web |title=CV Joint: how it works, symptoms, problems |url=https://www.samarins.com/glossary/cv_joint.html |website=www.samarins.com |access-date=14 February 2023}}</ref> This cover is usually made of rubber and called a "CV boot" or "CV gaiter". Cracks and splits in the boot will allow contaminants in, which would cause the joint to wear quickly or completely fail. An all-metal [[universal joint]] or CV located inside and protect by a [[Beam axle|solid axle]] (housing), swivel hub or closed knuckle may be desirable in harsh operating environments, where rubber is prone to physical or chemical damage. Metal armour and [[kevlar]] sleeves/covers may be used to protect rubber CV boots.

The CV joint is usually lubricated by [[molybdenum disulfide]] grease. The six spheres are bounded by an anti-fall gate that prevents the spheres from falling when the shaftings are perfectly aligned.