drive shaft question

[scout man]

I was replacing my U-joints today on my rear drive shaft and I noticed that the u joints on both ends are rotated the same way. Everything I have always been taught says they should be oposite each other - the whole equal oposite thing. Should I pull the slip yoke and rotate it 90 degrees? I am wondering if this is the reason my rear ujoint finally broke. I have had a vibration for a while, but cant think of when it would have been rotated unless it was that way when I got it a year ago.

[JeffX]

90 deg will give the least vibration. However, I wonder why there's no CV at the t-case?

[scout man]

because it isnt a CV shaft. My front shaft is CV, the rear does not need it since the angles are managable with a U joint shaft

[Jamie]

Do you mean the zerk fittings are in line with each other? I'm not sure what you are describing. Can you post a pic?
You are correct that the any weight on one side should be cancelled out by equal weight on the other end. Or are you saying that the angles of the driveshaft at the transfer case and axle are are not equal and opposite?

With a standard driveshaft (one u-joint at each end) then they must be equal but opposite (dog legged). With A CV then you point it straight with a slight downangle at the axle to account for axle wrap.

[scout man]

actually this is entirely a stupid moment on my part. I was talking about the yoke orientation on the ends of the shaft. But ultimately it is how it should be, the yokes face the same way. In my head I was thinking they should be ofset 90 degrees, but my head was just confused.

[Jamie]

I see, might just be time for a new joint.

[scout man]

just put 2 new ones in this evening! Mostly because I blew one out on the highway the other day, but then when I was checking out the other end it was about ready to blow too. They were probably 35 year old u joints though, so it was time :thunb:

[Jamie]

WOW! I'm lucky if I get a few years out of one and regularly grease them. They didn't know how to build junk when they built your rig! Old steel is the best.

[Brody]

Glad you got that sorted out. Here is a picture of how your drive shaft needs to be to avoid vibration. This applies to both single and double cardan shafts:

[JeffX]

LOL, I just looked at mine. Straight is correct!

[Jamie]

Glad you got that sorted out. Here is a picture of how your drive shaft needs to be to avoid vibration. This applies to both single and double cardan shafts:

When have you every in you entire life seen a drive line angle like this Pete? I hope you are josh'in us? Some times it takes me a bit to get the humor!

[Brody]

Not a joke...I was showing how the yokes on the driveshafts need to be in line and not at right angles to each other on the ends. My driveshafts are set up this way and I have never set up driveshafts in any other configuration. All of the pictures are from Tom Woods Custom Driveshafts:

http://www.4xshaft.com/index.html