Drivelive Vibration, On Hwy Only, Trans Or T Case?

Occasionally I get some drivelive vibration, on road,in high gear, 35-40 mph,under light load?
Suspension is tight, newish u-joints,and spring bushings.
Haven't built trans or t-case(If it ant broke, don't fix it).
Might be time for a 18 build?
Opinions?
Thanks
Ps, I've gotten so many bugs out of my toy,since joining this forum.

 

tires maybe?

 

How do you know it's from the drive line? These Jeeps can develop a wobble, though it's less common for the closed knuckle axles. Tire balance matters, as does condition of the kingpin bearings and pre-load. U-joints are another common source of vibration... even though they are "newish." U-joint wobble tends to go away under load. Typical the 18 gets noisy - not sure how it would develop a vibration. Noise is the usual first indicator for either transmission or transfer case issues. A vibration typically comes from an off-center rotation, like driveshafts or wheels.

 

Remove the rear drive line and take it down the road. Is the vibration still there? Check rear output bearing and slip joint in D-shaft.

 

Drove to lake today,back roads, bout 3 mile. Couldn't make it shake?
Had wife and son with me, and tires aired up to 25-28 psi, usually keep them 18-20 on farm.
Might be a tire issue?

 

Could be tires. Are they old, worn, what style? I had a set of old mud tires and they shook and wandered all over. The new 33" BFG All Terrain at 23 psi are great.

 

They are 32/1150/15 wild country mud tires.
15year old,worn erratic on the 2 that came off front of my j10,some early signs of dry rot,
About half tread. Basically brand new,lol!
It really could be the tires.
I'm in the process of having a second set of wheels and tires with a smaller,more street friendly set.
I'll test with different tires before tearing into t case.
Thanks.

 

Check for a bent rim too

 

Found loose locking hub retainer bolts, one backed way out.
I've had to tighten these before?
They are socket head bolts with lock washers, is this
common, fo them to not stay tight?
A cure?
Ps I noticed that when hubs were unlocked on road, no vibration!
Going all around jeep today and tighten all bolts?

 

Slop in the front driveshaft slip joint? Pretty common. Just keep hubs unlocked unless 4WD is needed.

 

Warn hubs were delivered with special tab washer that you would bend over the bolt head to lock them in place. I put studs in my hubs with Locktite, and used nylon insert nuts. The original tab wahers, or safety wire, might be other solutions. Yes, hub loosening seems like a common issue.

 

X2

And yes, locking hub bolts can be a problem to keep torqued. Studs may work better.

 

The extra weight of wife and kid could've dropped your suspension just enough to straighten out your driveshaft to minimize the misalignment. Make certain the ends of the shaft are phased properly. Google is your friend if unsure what I mean. If your shaft is out of phase, the lightest bit of misalignment will make you fillings hurt at 35-50 mph.

 

Under NO circumstances should you mention it to the wife....

 

Ok, hillbilly repair attempt #2.
I think the chrome on the threads is a big problem,(I've had to scuff new valve covers
to get the gasket to seal to the chrome surface).
I put the threads against my bench grinder wire wheel an pushed hard, really scuffed
The threads up good.
Then blue locktite.
Then new star type lock washers.
Time will tell!

 

What is max angle for rear u joint, t case end?
I have pinion shims on the axle end.

 

Both joints being in phase and at the same angle of misalignment is more important than the actual angle number. Joints can run at a pretty harsh angle with the only drawback being longevity.

If the two joints in the shaft are at different angles, that could be part of your vibration.

Excellent visual aid:

 

I'll phase it tomorrow.
Thanks.

 

Front shaft out of phase! Just found it.
I'm betting the one the one thing leads to another saying works hear, the out of phase front shaft, accelerated the hub bolt loosening ?
Under repair as we speak.
Rest of day is mine, jeep repair, and hopefully test driving(might get lost)?
Thanks for the ideas.

 

2 notches out of time on slider.
Only been like that bout 3 years?
I'm blaming it on TN whisky the night of original install? LOL
Assembled, greased, and waiting on rain to stop, or at least slow!
Hope to have a , vibration fee report next post?