Puzzling driveline vibration

[CaliXJ]

it's best just to pick up a dial indicator, you can get them for relatively cheap. i think harbor freight sells one for like 19 bucks with a magnetic base. that way you can narrow down the runout and figure out where it's coming from. they're pretty handy for a lot of things.

I actually have one, I'm just not sure where to stick it on the Jeep to get a measurement.

If the dial indicator has a fairly far adjustable reach to it. See if it will stick to the e brake section in the tunnel. Not e brake itself but the little box the e brake rod pokes out of.

If that doesn't work. Use your jack. "assuming you have a good one other than stock" Jack it up so the jack disk sits right next to the output yoke. set it up and slowly spin yoke by hand.

 

[Israel]

Good news and bad news. Good news is I fixed the vibration. Bad news is I'm a moron.

I put the conversion joint in backwards on both shafts so that the zerk fitting faced the pinion yoke. I was smart enough to notice right away that the zerk itself wouldn't clear, so I pulled it out and planned to source a low profile fitting. Unfortunately, I wasn't clever enough to check that nothing else was in the way.

Thanks for the help, everyone! Here's a shot of the new shaft after I flipped the joint around. It's next to the spare shaft that has the joint in the wrong way still.

 

[Vanimal]

LOL well cool, glad you fingered it out. thanks for posting up the cause, now i know to look for that in the future.

 

[Israel]

Truthfully, I hesistated because it was so dumb, but I hate searching and finding threads about a problem I'm having and having the thread end before they posted the solution.

 

[Vanimal]

i hate that too, so glad you did.