Ok, but your not answering the question. Does the pitch of the whine change with the rear shaft in?
I think you should do what I said earlier. Put the front end up securely on jackstands with the rear shaft removed and see if you can make it do the same.
And if not the same with the rear.
It will isolate front and rear at least.

 

you could take it to a shop and put it on a hoist to check for the sound. that should take the mud tire noise out of the equation.
or possibly take to a drive clean facility and have them run it on the rollers to check for sound. should be easy enough to pin point whether it is tires or gears.

 

The unfindable howl on my '98 ZJ turned out to be the front differential.The howl came and went, but was worst at 50 mph. With the diff under the engine and mounted in rubber, it was a PAIN finding it! Only after I replaced the right side wheel bearing and found the worn out ball joint that I figured that the diff gears were screaming. Figured the whole unit was tired so... $400 for a bone yard axle and she runs sweet and quiet!

 

The pitch of the whine is not dependent on whether the front or rear driveshafts are in. The only thing that changes the pitch, regardless of which DS is on, is the speed of the rotation of the wheels.
You guys are right, I need to get the front and back off the ground. Since I'm due to change the fluid in my front anyway I'll probably pop the covers first and look for any visual indication. Thanks for your help.

 

The guy who said removing the shafts and jacking the front and rear one at a time has it down. That will tell you where exactly the noise is coming from. It might take some work, but its free and will pinpoint the issue.

 

Id put my money on rear axle bearings.......

Subscribe.T for when he finds out what it is.

 

I took it to Colorado Axle and Gear in Denver.

They said the gears were installed incorrectly. They're going to document everything.

The mech raised it up, removed the diff cover, and showed me how it had been setup wrong. Thanks for everyone's help & advice.

 

was it the contact pattern?

 

Only goes for saying if the guy set up both axles the same way... the would make the same noise.

Most of the time a trans/t-case bearing sound is cured by added fluid.


The f'ed up thing is you believed in this guy, and after this I wouldnt let him change my oil

 

So I hope you Goto the guy who set them up and get your money back. No matter what ratio you have the should be silent.

 

after watching Extreme 4x4 i think i would know how to set up ring n pinion... although i never have. HAHA just kidding.

cut the mech some slack but do try to get some of the cash back or atleast a credit for other work he may be more capable of.

 

Hell I slept a Holiday Inn Express...

Today TV and the Internet making them more capable then they really are.


Setting up gears isnt really that hard with the right tools and patience. Bad thing is the right tools to do a install and you are at close to 1k, so even some professional mechs skimp on the tools. This is a service anouncement to all ppl shopping for gear installs.


Like I said.. I wouldnt let this mech change my oil after doing two bad gear installs and blaming a t-case bearing. n I would proceede to tell him to give me back my money, or I would see him in court for what it actually cost to fix his screw up.

 

Gears can still howl with no driveshaft/no pressure on them. My gears howl when im in neutral, but not when I have pressure on the gears.

 

no matter what kinda of scenario you come up with there will either be drag on the gear or pressure. the force to spin the drive shaft or pinion while coasting is still present no matter what the jeep is doing as long as its moving.

The only way to make gears not howl is buy quality parts and have a quality installation done.

If your gears are howling they are not set up perfectly. Which could be acceptable or not for the gear manufacturer if you ever had to send them back if there was a failure.

 

I spoke with him and we got everything squared away. It was a different brand of gears he was used to using and he didn't seem that confident in them after I told him about it. Despite the mishap, I have quiet gears now & I'd recommend his business.