drive line angles

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Dec 7, 2005 | 09:52 AM

78bigbronco

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Fleet Mechanic

Joined: Jan 2003

Posts: 1,812

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From: Central Ohio

drive line angles

I read in another post that if you have a u-joint then your angles should be matched on each end of your driveshaft and only with a cv joint should you try to adjust the rear pinion angle to be nearly zero. Is this true? And this might be really basic but what is the actual difference between a cv and u joint? My 78 bronco has 4 u joints in the rear driveshaft with one of those double ended pieces that I thought was called a double cardan joint or something like that? (not sure if I got that terminology down). I did have a slight problem breaking the rear-most joint multiple times and I thought I had extra spring wrap due to a couple broken leafs, but I think my angle might have a bit to do with it also. Best I can tell is it is at or slightly above zero with the driveshaft.

Dec 7, 2005 | 10:38 AM

ivanribic

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From: Spokane, WA

Quote:

Originally Posted by 78bigbronco

A double cardan and a CV are the same thing. With a single u-joint the speed of rotation surges more or less but the CV (double cardan) uses 2 u-joints and they balance that change in speed out between the two of them, hence they are called a constant velocity joint.

You are correct that for a driveline with a CV at the t-case you want a 0º angle at the pinion and for a regular driveline you'll want the angle of the pinion joint matched with the angle of the t-case. This will help balance out that speed surge that causes vibrations in the driveline. One thing you need to remember on that rear axle is even though the pinion angle may be at 0º when you're sitting still the pinion will tend to wind up when you're driving. Unless you have ladder bars to prevent this you'll want to point that pinion down a few degrees so when you give it throttle it will come back up to a neutral angle.

Hope that babbling made sense.

Dec 7, 2005 | 09:52 PM

pokerpuller

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so if i ran the regular u-joint at the differential, and a cv joint at the transfer case, i would want my pinion parallel to the ground, or pointing right at the t-case?

Dec 7, 2005 | 10:11 PM

KubotaOrange76

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Joined: Feb 2005

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From: GA

technically it is called a double cardan joint....because it has two u-joints, a cv joint is whats found in the front of a fwd car..

most people call double cardan joints cv's so.....

itsbecause a cv is true to "constant velocity" while a double cardan joint slightly speeds up and slows down through it's rang eof motion...callthem wu tu want

Dec 8, 2005 | 05:08 AM

460

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From: In the Middle

Quote:

Originally Posted by pokerpuller