2 degrees 2 much?

[highmtnjeepn]

The yoke on my rear axle is 2 deg. lower than the xfer.
Is this enough to induce vibes? I'm trying to narrow down the culprit. Being slightly lower is good I thought, so that as power(cough) is applied it rotates up and the angles will match. Whatcha think?
Thanks

[Tippy]

Did you do an axle swap or is it the stock axle? When I swapped my axle in the rear, I pointed the pinion toward the t-case so the drive line was in line and welded the pearches there. I have no vibration problems.

[uglyjeepoffroad]

Doesn't sound too bad.
How steep is the driveshaft angle?
U-joints in good shape?
Are you running a cv shaft?
Just some ideas.

[RickB]

There was a very good detailed post about this not long ago. In short, it said that if you're running a driveshaft with u-joints at each end, then the angles must be the same or within a few degrees (as in your case). If you are running a cv driveshaft, then you point the differential at the transfercase.

I would think that 2 degrees is OK and won't produce vibration. That's assuming that the angles are not too extreme on the ujoints.

[RedCJ7]

See here for driveshaft geometry explanation





HTH

[RRich]

Great drawings! To add to that just a tad - no idea if yours is set up this way.
But if the slip joint is in the shaft, the splines can go in any position. Make sure the ends are the same in relation to each other, not skewed. In other words if you drew a verticle line through one end, the other end should be verticle too.
Having them not in parallel will create vibrations.

[highmtnjeepn]

Thanks for the replies...
To answer some issues: it's the stock d44 rear. The skyjacker 4" wrangler springs came with some 4 degree shims. I took them out and am running without any shims now.
The driveshaft is stock. U-joints in good shape. Driveshaft is in phase.

[LEVE]

1. If you've actually got 2* rotational difference,
2. Properly measured...
3. The you're about perfect.
4. There is needed at least a degree and a half of difference,
5. To force the needle bearings to rotate.
6. This is what lubes the U-Joints,
7. If the bearings don't rotate,
8. The joint wears out.
9. It's a fine line you walk with a lift,
10. When setting angles.

[mobdawg]

I have an added question to this post...I installed the RE HD tailshaft kit and a Tom Woods driveshaft to mine and the diff was pointed way low so I took the degree shims off of some 4" lift springs and installed them but now my pinion is pointed slightly high...not sure of the degree, but it's noticeable enough. I don't have any vibes during normal driving but under heavy acceleration my fillings come loose from the shimmy. Think it's cause the angle is changing due to axle wrap or is it because of the initial angle?

[highmtnjeepn]

I'd say your pinion angle is borderline too high at rest (or at constant speed). When you accelerate, the axle wrap puts the u-joint at an angle where you're noticing the rotational speed changing. I'd be curious to know what your angles are??