Quote:
Originally Posted by "007"
Mahlon must have lost it in translation. "007"
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Oh now, let's be nice to Mr. Mahlon. He's absolutely correct such high-end taste as he must have. A half-shaft CAN have u-joints and a half-shaft can also NOT have u-joints all depends on the suspension type.
In a multi-link or 4-link or independent suspension drive systems (used on fancy sports cars and R/C cars/trucks) there are indeed 2 half-shafts with full universal joints (or CV joints) on each end (total of 4 joints) that transmit power from the differential to each wheel. Since each wheel is suspended independently the half shaft must move along with it. You can see these half-shafts in the modified Jag IRS pic below. The half-shafts have the black rubber bellows on them protecting the CV joints from dirt. Also notice the brakes (disks here) can be mounted inboard on the diff itself thus reducing unsprung weight - a critical handling/performance attribute.
In a full floating hypoid differential solid axle (like rear drive cars and our big bad HD rig chassis drive axles) there are also half-shafts but they are solid. They can be solid as there is no suspension travel between the wheel and the differential. These half-shafts also transmit power from the differential to the wheel.
A "propeller shaft" or drive shaft looks like a really long multi-link half-shaft and transmits power from the transmission to the differential and it too has U-joints or CV joints on it to account for chassis flex and in the case of a solid axle for the suspension travel of the axle. The prop/drive shaft via the differential drives the half-shafts - be they U-jointed or not! Of course, in an IRS vehicle the prop/drive shaft may not actually need U-joints because the differential does not move. So, a prop shaft can in some cases not even have u-joints. Your FWD car takes power straight from the transmission to the differential in a transaxle arrangement. Solid all the way w/ flippy floppy CV joints on the half-shafts for the suspension travel.
Hope this helps keep our common language common. It really is!!!!!!!!
Or here with the white coil-over strut suspension with the white bellows tie rod, and the black bellows half-shaft.
Or here in the R/C vehicle world...