Rear drive shaft phasing with SYE?

[B.E. Coyote]

Should the yokes on the shaft be aligned or the yokes on the diff and SYE?

I didn't pay attention when I pulled the drive shaft for an axle swap and it came apart. I have vibration at above 60mph. Not sure if I am 180 out, completely wrong or it is something else. The jeep was bought as a project so I don't know if the vibe was there before.

I think when I put it back together, I was counting the sye as a double cardon and found info to do it this way.

 

[macleanflood]

 

[B.E. Coyote]

Cataract surgery next Thursday but I think I am seeing differently in this video from Woods? At around 3:30.


View: https://www.youtube.com/watch?v=1kFku55FbZs

 

[macleanflood]

So you're chasing a vibration right?

Are you sure it's from the rear?

Have you checked air pressure and had the tires balanced?

Check the alignment with a tap measure?

Pull the front shaft, go for a drive and see if you have vibrations? Reinstall, pull the rear shaft, repeat?

Also shake your driveshafts. Should be zero play.

-Mac

 

[B.E. Coyote]

Yes, chasing a vibe. No not 100% sure from where.

Brand new tires and balance.
Brand new alignment from reputable 4x4 shop.
All 33" tires 26 psi on the dot.

Zero play in the rear drive shaft.

I was planning to just swap the rear yoke 180 because it came apart when I did the axle swap and I had a 50/50 chance of it being wrong, but now that I look at it, I think I need to try a 90 degree change then a 180 if that doesn't work.



The vibe only shows up above 60mph. No issues in driving that speed with just the front wheels engaged?

 

[macleanflood]

Driveshaft came apart is what you're saying? And you're concerned about phasing?

Might want to take it to a drive line shop and have them figure it out.

-Mac

 

[RussinIdaho]

It looks like the rear pinion is high.

 

[CMBD]

Your driveshaft is off 90 degrees one way or the other. Its out of phase.

 

[B.E. Coyote]

Your driveshaft is off 90 degrees one way or the other. Its out of phase.

View attachment 703264

Thanks! That is what I was thinking. I'll switch it around tomorrow.

 

[GoldenGorilla]

Driveshaft came apart is what you're saying? And you're concerned about phasing?

A shaft spline stub end can slip out with an X-spline when out of the vehicle. Not a big deal but it's possible to clock it at 90.

 

[macleanflood]

A shaft spline stub end can slip out with an X-spline when out of the vehicle. Not a big deal but it's possible to clock it at 90.

Also possible to get it off just a few degrees. It's splined after all.

-Mac

 

[B.E. Coyote]

Turned it 90 degrees and ran it up to 70 mph. Much, much better. Being paranoid, I think I might feel something sometimes but if I wasn't trying to feel a vibe, I would never notice anything. Probably just a lifted jeep and AT tire thing.

I thought about trying it 180 degrees out from where it is to verify, but probably won't bother. If I was 180 out it should be worse than just being 90 out correct?

Thanks!

 

[OldBuzzard]

Driveshafts are spin-balanced at the factory. It's best to get it back to the exact configuration it had when balanced.

Now you have the phase right, that corrected the vibe caused by wobble.

You may or may not have the best alignment for the original configuration. You could switch it 180°. I think I would just run it for a few weeks to see if the "imagined" vibe is real. Mine has "imagined" vibes too, and then when I get to a different section of pavement they go away. Tires and road smoothness.