Calgary Jeep Association
4x4 Related Groups => Tech Talk => Topic started by: bushman67 on May 30, 2010, 09:23:57 PM
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Hey guys... for all of you on Saturday's cleanup whom I bent your ear talking about my mystery clunk, it just gets more obscure.
Symptoms... will not clunk when cold... after 10-15 hwy drive and everything warms up, a clunk will develop in what is the Front Right. If I hoist it up, and spin tires by hand... no clunk, no problems.... put it in 4wd to turn the front wheels and... clunk, clunk, clunk. Oddly, the slower you go (right now to inching along), the faster the clunk gets.... nothing to do with rotational speed of tires or drivetrain. will happen in 2 or 4 when on the ground... must put in 4wd to make clunk when in the air to spin front.
Saturday: this foray in the woods was this rig's first real little 4x4 test... note that I didn't get any abnormal sounds when grinding around in the muck or ledges. This sound described is not heard while wheeling. ... only when coasting at a slow pace.
Oddly... the sound stop with the slightest of brake pedal. If I keep putting around the neighborhood, it will continually get worse..... from a click to a clunk to more marble like sounds. Let it sit for 10-15 min... sound almost gone... let is sit 30 min sound gone... until you run it for a while again.
So, after many theories, and fixes... axle ujoint, unit bearing, and now swapping rotors, I'm still no farther ahead. I've run without axle ujoints (just stubs)... sound still presents... I have run WITH axle ujoints in place and NO front DS... sound still presents.
Theory #62 --- something inside the Dana 30?? --- what if an inner bearing was going?? It heats up and then starts to bind.... I'm doing an alignment this week, to reset my toe-in after the lift... any chance a toe-in problem could cause some odd wheel rotation ratio that binds up the D30's internals.
Anyone have any other theories.... speak up!
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I've run without axle ujoints (just stubs)... sound still presents... I have run WITH axle ujoints in place and NO front DS... sound still presents.
That little test just ruled out your D30 internal possibility.
My best guess is your brake backing plate is really close to rubbing the rotor and when things warm up, it touchs and makes the noise.
Just pull the backing plate and toss in the scrap pile, it's not needed.
Vince
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The fact that it goes away when you apply the brakes tells me it's in the brakes. I would start there.
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There's loads of clearance on the backing plates... oddly enough, when I ran today without the front DS, it took much longer to 'present' the sound, yet, when I ran it 4wd, it presents very quickly.
If I run around the subdivision, making lots of turns and NOT using the brakes... the sound will present after a while... but on the other side, if heat up the brakes real good, doesn't make it happen any faster or worse. If it was the backing plate it would sound like when you get crap/mud on your brakes right? -- this is clunk, that turns to marbles... like a totally toast u-joint. But all ujoints & unit bearings are good.
I'll pull the backing plates anyway, however, next theory?
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I thought it was brakes too, but again... everything checks out... nothing warped, nothing chewed up, nothing loose, or binding.
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Just my two cents but it sounds like something in your hub assembly maybe a spring or tooth broke on that side
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One time I Lost (or forgot to install) one of my bolts for my brake caliper.It would actually work fine but would bonk around. Sounds like you've tried a lot of things, its probably something ridiculous lol
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Theres way to much inconsistency to internet diagnose it.
No doubt its probably something simple, but without actually looking at it, non one will be able to tell from these descriptions.
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Billy is totally right. Oddly I've eliminated all things presented exept total isolation of my front diff. No axles & driveshaft. Sound only presents when coasting. On brake or under power in 4wd. No sounds.
I've run once with NO left axle as I was doing what I suspected at that time as an axles ujoint. The sound still presented itself after some time. so I thought it was unit bearing. But with that replaced. Same sounds.
Note. All brakes check out fine. And I get no odd pedal feedback during the sound. I also suspected LC bushings, but once the sound starts and I get it back home, it will continent while in the air / hoisted.
I need some one to take a ride with me, listen, and I can the start crossing off what I've already done.
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Sounds carry very funny in a vechicle. I've thought my sound was from the front and in fact it came from the rear. I've had transmission mount do the same kind of noise only when it was hot would the mount move enough to let the trans move and hit the body. You looked every where in the front end how about the rear end? I hunted for 2 weeks for the clunk in the rear of my jeep only to find out stuff i was carrying was making the noise. But the noise was just like a lca.
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Definatly front left is the affected side.
When all warmed up on hwy and making the clunk sound, I ran it inside an hoisted off the ground & ran I'm 4wd in the air to get front to spin. There us enough clunk to make the front left axle to jump a little. I pulled the tire, rotor & caliper. Same sound, same side.
Grrr. Jeeps and their "sounds". Should just buy a better stereo to drown it
out. Laugh.
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are the lug nuts tight? haha, could it possibly be control arm bushings? i have a friend with a very similar problem on his zj....
???
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have you checked your front trackbar on the axle?
I had the hole oval itself out and I would get pop sounds or clunks and thought it was the left side, but the noise and vibes transferred them selves from the right side up to the left making me think something on the left was poopoo.
and second on the lugs maybe not being tight.
if they are loose or damaged, the heat of driving could case them to stretch a bit and you would hear clicking and possibly clunking as they heated up more. I don't think the brakes would change that too much outside of moving the rotor out and tightening things up a bit.
if the studs had been overtightened at some point, they are likely stretched and will not hold the load and will loosen off even if you tighten them to spec. if off road there is less heat build up usually from slower speeds, so that may reduce some of the noise.
just a thought.
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track bar bushings, bolt, and heim joint all replaced... lugs not or wheels not part of the equation...
Sounds still presents itself (once warmed up on the road) when up on hoist, with no wheels, no rotors, no calipers... just hanging there. again... axle will jump slightly when the clunk happens... axle ujoint and unit bearing replaced too... sound has yet to be "changed" with any of these fixes. Again... everthing starts to point to the front diff in some way,
However, to wrap this up... I'm going to run with axles & drive shaft removed next week... if the sound stops then it's 100% inside the diff somewhere.
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I will applaud your willingness to put up with all this hassle Rob. Wanna save yourself some aggravation?
Go to PNP or Robin"s Used Jeep Emporium and get another D30. This is not a rare or expensive item. Swap that Diff out! Trying to diagnose this problem will make you go bonkers and swear off Jeeps all together. My friend had a "mystery" ailment that we could not fix. We got a used D-30 with the same gear ratio and swapped everything out in an evening. Problem was solved. Dana30's are like Bic lighters dude...
It's just an idea. I hope things work out for the best, and we see you out on the trails soon. Good Luck!