Posted by chris case on Thursday, December 23, 2004 at 1:42PM :
In Reply to: Clint and picture posted by MoparNorm on Thursday, December 23, 2004 at 1:17PM :
Note the angles on the axle ujoints, about double the drive line angle?
Clint, needle bearings is needle bearings, the Dodge design IS a modern one.
Vaughn, paralellism is critical, but u-joints have a limit to angularity. I think it is about 20 degrees. The single cardan joint is not constant velocity: at a constant input speed, the output speed will vary as the joint turns at any angle. It's because the leverage of the parts change from + to 0 to - as the shaft rotates. You need both ends to have the same ( or opposite) angles so as the center section(drive line) varies in speed copacetically- the input and output are constant, but the drive line is constantly accelerating and decelerating, 8 times per revolution. The double cardan joint allows the major hunk of shaft to maintain constant speed while the little 'double cardan' chunk varies, eliminating lots of vibration.
The constant velocity joints used in the front axles of old Dodges (rczeppa and bendix) and front wheel drive cars, have balls that slide around as axle angulates, maintaining even leverage and even, constant, velocity
PS: the proper 'clocking' of a driveline should be to have the 2 'axles' on the shaft parallel, just like the 'double cardan' (constant velocity) joint. 90 degrees off will accentuate the variation of speeds, causing lots of bad vibes. Most PW's I've owned had at least on badly assembled, my current one does.
Maybe more than you need to know,
Chris
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