Driveshaft phasing

[DLH]

When I bought my truck, it didn’t have a driveshaft. I found one local to me that was free. I am taking it apart to cleanup and rebuild. I noticed that the front yoke (ujoint) is not in line with the rest of the u joints. Looking at the pic its sitting about 11 o’clock. That’s not right, is it?

[kwmech]

No it's not, and it's actually sitting at 2 o'clock or 8 o'clock if it's 180 out

[72SB]

FWIW GM did that on cars, Camaro back in the 1st gen years in an effort to eliminate driveshaft vibrations. On paper the "theory" looked good but in practice it did not. My 67 Camaro had it. The idea that under load the out of phase U joint would eliminate driveshaft vibes, especially on vehicles with low rear end gear ratios.

You can have the yoke end removed and positioned in line with rear at a good driveline shop and have the shaft re-balanced

If getting a new DS..and your wallet is thick enough. Get a Dennys DS, especially if running 3:73, or lower, gears

[DLH]

I removed the yoke and tried to reclock it, but it is a half spline off from lining up if you know what I mean. I'll get it cleaned up and take it to the shop and let them cut the end off and fix it. At least the driveshaft was free.

[Keith Seymore]

"Phasing" was one of those design theories that came and went, depending on what was en vogue at the time.

K

[tdangle]

Interesting note: I have a 2 piece drive shaft that was rebuilt and balanced by a driveline shop. In trying to track down a vibration I have at speed I unphased my driveshaft a couple of different ways with absolutely no change in the vibration. In theory it makes sense, in practice not that I could prove.

[Bigdav160]

That thing has to shake like crazy

edit: maybe not if the working angle on the front joint is 0

[67C10Step]

Hmmmm, I need to crawl under my 67 and take a look. I am almost certain that is exactly how mine was when I pulled it out for rebuild and how I put it back together. I've not had mine much above 55mph in the few miles I've driven it but I've not noticed anything overly bad on the vibration front.