confusing driveline noise, running out of ideas.

[mtl3314]

my jeep:

1990 xj 4.0 automatic
np231, dana 30 with universal joints, not cv
other tan the noise it drives fine

I originally posted this:
http://www.naxja.org/forum/showthread.php?t=1015098

I have a horrible clanging shutter that emanates from my front end whenever i go over any slight disruption in the asphalt, its almost too much noise from such minuscule bumps. i hit a slight crease in the road and a loud shutter emerges.

Heres what i did either to remedy the situation or replaced recently anyway:

new motormouts (brown dog polyurethane)
new transmission mount (oem rubber)
new control arm bushings (all eight are polyurethane)

i opened the front differential and it was bad (read the link above for more info on that),
so i removed the driver side axle, but left the stub end so the bearings don't fall out.

i removed the front drive shaft, but i did not remove the inner passenger shaft that connects to the diff because the front drive shaft is out and 4wd disengaged so that system should be closed off.

so now my jeep is 2 wheel drive, which sucks; but what sucks more is that its still making this noise.

it made the noise before i put in the poly control arm bushings so its not drive line vibration being transmitted through them, i had the motor mounts for about 5000 miles before the noise started so its not them either. the u joints were good, though ones removed now, so its not them, and this noise is way worse than a bad u joint. i took out the front drive shaft its not that. the hub bearings are good so its not them.

i am at a loss, and i really don't have the time or work space or appropriate tools to rip the whole front end apart in my front yard, i had to pay a mechanic just to do the control arm bushings. maybe the mechanic did a bad job but its not too hard to do and they're all in as far as i can see, i must be missing something.

 

[ehall]

temporarily remove sway bar to eliminate the arms and bushings

 

[rdeskater]

check ball joints, tie rod ends

 

[mtl3314]

its not the tie rod ends or the ball joints i checked them, also the noise doesn't sound like those
it sounds like something heavy is loosely secured and bouncing around only there is nothing hanging and everythings where it should be and the thing drives like a dream.

perfect example, it sounds like i strapped a hi-lift jack to the top of my front axle and the handle keeps slapping the jack body, anyone who has one will know that sound.

 

[kastein]

Sway bar bushings or ends I'd guess...

Could also be shock bushings. I had a really wacky clunking/banging noise from my right rear that ended up being a completely shot shock absorber bushing.

 

[matttaylor1976]

might be a stupid question, but what type of rims, and do you have center caps on them? I had those chrome center caps on after market rims, and they made a horrible racket. And definitely check your shocks.

 

[mtl3314]

rims are stock no hubcaps, i will definitely check the shocks, though i replaced them with skyjacker units about 15000 miles ago.
the shock mounts might be worn, i just checked the top mounts but must still check the bottom ones as well as remove the swaybar, i don't think the swaybar can make this brand of noise though, shocks might make it.
i notice the mechanics decided not to disconnect the swaybar while replacing the control arm bushings and bent the mounts, guess its time to pickup those quick disconnects i always wanted.
i really hate mechanics anymore, my fault for going cheap.

 

[mtl3314]

bump

 

[KryptoniteXJ]

did you ever remove the carrier from the d30 I would put money on the carrier bearing being bad.

 

[my2monkeys]

If it drives like a dream it's gotta be something simple like the hood prop rod banging on the inner fender. Check the transfer case skid plate bolts, the rivnut on my 89 popped loose and was causing a banging noise.

 

[mtl3314]

everything in the dana 30 is bad, it ran dry when the seals went in the middle of a 1200 mile trip and i didnt realize until it was too late, i removed everything connected to it though so its just bolted in place until i take the passenger side apart to rebuild the entire axle.

it is possible the carrier is making this noise but there just isn't much that can rattle in there except for the spider gears.

 

[mtl3314]

there are no skid plates on the bottom of my jeep currently, the exhaust is secure, its definitely something bigger and definitely at least a foot below hood level.

 

[CherokeeManatee]

Did you check to see if there is a hi-lift strapped to the top of your front axle? That can sometimes produce a noise similar to what you're hearing

But seriously, I know you checked your tie rod ends but is there any play in your tie rod? I have a '93 and a stock tie rod (bad bushings) where I can wiggle it forwards and backwards about 1/2" and it makes a clanking sounds when I go over bumps, potholes, make sharp turns, or stop short (or any combination).

Go through every component from axle->hood and see if there's any play. Don't be a wimp, throw some weight into testing each component.