AMC Eagle Den Forum

The Shop => 4X4 and Driveline => Topic started by: nvsteve on March 09, 2011, 09:34:30 PM

Title: developing a rumbling noise and vibration
Post by: nvsteve on March 09, 2011, 09:34:30 PM
Just tonight I noticed a rumbling noise and vibration that I  first thought was a tire going down.  The car is in two wheel drive.  I can feel the vibration in the steering wheel.

It seems to begin at about 35 mph and seems to diminish or go away completely above 50 mph.

I'm thinking Ujoints?   shifts ok, no slippage, no leaks. 

Any guesses?

Thanks
NVSteve
Title: Re: developing a rumbling noise and vibration
Post by: shanebo on March 10, 2011, 12:15:23 AM
Sounds like a U-joint...the only other thing I can think of that would cause somthing like that would be a wheel bearing..but thats a continuous noise/vibration that is proportional to your speed and it doesnt come and go. I would crawl under there and jiggle the drive shaft and if theres alot of wiggle room then she'll need u-joints.

Also, the drive shafts are balanced..much like the wheels..If for some reason on gets out of balance from say a glob of mud or a lost weight, it can cause vibrations and noises that mimic that of an out of balance tire...speaking of which might want to take a peak at your rims and see if theres anywhere a weight may been knocked off.

Best of luck!!
shane
Title: Re: developing a rumbling noise and vibration
Post by: LaGuardia on March 10, 2011, 05:27:44 AM
I'm still in the process of fixing this thing on my Eagle, so I could be biased, but don't disregard the hub bearings problem.

Mine were shot bad, and the rumble and vibration occurred only at low-medium speed (at higher speeds probably the centrifugal force moved something and silenced it) and when the weight of the car shifted to the right (during a lane change, for instance).

Slam a jack under the front (one side at a time), raise a little, grab the wheel and check for play (horizontal and vertical). If it moves, spin the wheel by hand and listen for noises: you shouldn't hear any (maybe some pad-rotor related ones). If it moves and makes noise, that's bad!
Title: Re: developing a rumbling noise and vibration
Post by: LaGuardia on March 10, 2011, 05:37:57 AM
...oh, and take into account that the hub removal process is a PITA. So if you plan to do it yourself you can take your time but if you need to have it done by someone else do it now. I delayed and delayed and in the end I found myself with an un-movable car. So no option of having it repaired unless I had it towed to a shop, too.

That's why I'm butchering my fingers under jackstands in my yard removing a frozen bolt at a time.  ;D

(it's funny, anyways)
Title: Re: developing a rumbling noise and vibration
Post by: nvsteve on March 10, 2011, 07:27:13 PM
update --

jacked up the front wheels and checked for wobble or play, none to speak of and no noises when I spun the wheels.  no evidence of bubbles or blisters on the tires.  I checked the ujoints also, seem ok to me,  I greased the front coupling while under there.

The only thing a visual inspection revealed is the left side cv boot is torn badly.   Could that be causing the vibration and rumbling?  Obviously it will have to be fixed one way or t'other.  I think the job is beyond me.  Would a repair shop be able to get parts and fix it?  If yes how much would be a fair price to fix it?

Thanks again all who provide valueable input!

Steve
Title: Re: developing a rumbling noise and vibration
Post by: IowaEagle on March 10, 2011, 07:39:40 PM
A bad CV joint could.  Has all the greased leaked out?  If so the joint could be on its last legs. 
Title: Re: developing a rumbling noise and vibration
Post by: jim on March 10, 2011, 07:41:36 PM
That half shaft is a do-it-yourself project.  It does take a few somewhat specialized tools, but nothing you won't need again if you plan to stay in the Eagle world.   There is a very good "how to" in the eaglepedia.  My first one was somewhat imtimidating but I don't hesitate to replace one now.  You can get them reman from most parts stores for - oh - $70 or $80  I suppose.  It's not much more expensive to buy them new and you don't have to return them for the deposit.  Some us have had problems with reman half shafts fitting the hub but others have had no problems.
Title: Re: developing a rumbling noise and vibration
Post by: mudkicker715 on March 10, 2011, 07:48:29 PM
Be sure they match in size. The 4 cyl is smaller than the 6 cyl and they interchange.its definetly visible.
Title: Re: developing a rumbling noise and vibration
Post by: IowaEagle on March 10, 2011, 07:51:01 PM
I don't think you can even get the 4 cylinder ones anymore???
Title: Re: developing a rumbling noise and vibration
Post by: nvsteve on March 10, 2011, 07:52:58 PM
yeah its dry as a bone.  I see that I can get the rebuilt shafts from NAPA for $70 each.  

I don't do much wrenching any more,  I did look over the how-to in the Eaglepedia.  On paper it doesn't look too tough I admit.  But I think I will check the price of repair at my local shop before I put myself through it.

Steve
Title: Re: developing a rumbling noise and vibration
Post by: shanebo on March 10, 2011, 11:18:38 PM
It shouldnt be terribly expensive at a shop....I dont really like wrenchin if I dont have to either.
Title: Re: developing a rumbling noise and vibration
Post by: nvsteve on March 11, 2011, 12:30:06 PM
I have to ask.....when the car is in two wheel drive,  do the front shafts spin with the car in motion?  Just trying to understand if the noise/vibration I have is caused by the CV. 
Title: Re: developing a rumbling noise and vibration
Post by: shanebo on March 11, 2011, 06:30:37 PM
They do
Title: Re: developing a rumbling noise and vibration
Post by: nvsteve on March 16, 2011, 05:43:05 PM
Update.....the new axle is installed,  but the mechanic says I still have the vibration.  Mechanic still checking, thinks it might be the ujoints.  It needed the axle anyway so not a total waste.

What I noticed driving it to the mechanic is that if you put the car in neutral and coast,  the vibration goes away, so I think that rules out a wheel or hub bearing problem.

More to follow
Title: Re: developing a rumbling noise and vibration
Post by: shanebo on March 17, 2011, 12:18:23 AM
definatly starting to look like a ujoint/driveshaft kind of issue...That new axle is still a very good investment!!...It will save a headache down the road. ;D
Title: Re: developing a rumbling noise and vibration
Post by: nvsteve on March 17, 2011, 07:33:08 PM
Picked up the wagon.  Running good now and my mechanic gave it a thumbs up.

New LF axle, new rear ujoints, new serpentine belt, repaired broken alternator bracket.  My 84 wagon should be flyin' high for awhile.

Steve
Title: Re: developing a rumbling noise and vibration
Post by: IowaEagle on March 17, 2011, 08:15:47 PM
That's great to hear.
Title: Re: developing a rumbling noise and vibration
Post by: shanebo on March 17, 2011, 11:18:13 PM
Glad to hear that beautiful bird has a clean bill of health now!!
Title: Re: developing a rumbling noise and vibration
Post by: nvsteve on April 21, 2011, 05:30:39 PM
 dna
Title: Re: developing a rumbling noise and vibration
Post by: mudkicker715 on April 21, 2011, 05:35:55 PM
So in other words your leaking case fluid into the trans?

How much would another car rob you of?
Title: Re: developing a rumbling noise and vibration
Post by: nvsteve on April 21, 2011, 07:47:06 PM
well I thought that meant the transfer case was leaking on the ground.  I do have fluid on the garage floor.

Yes I hear you,  any used car is a gamble. 
Title: Re: developing a rumbling noise and vibration
Post by: mudkicker715 on April 21, 2011, 07:59:44 PM
Ifyour leaking in the middle, best guess is your torque convertor is unloading thus overfilling your trans and than leaking.
Title: Re: developing a rumbling noise and vibration
Post by: jim on April 21, 2011, 10:35:44 PM
Do you suppose by front output seal he means it's leaking at the front yoke?
My tranny shop hasn't been able to stop the leak there on the 83 wagon.
Right front axle is something you can do. 
I would try to find out why he thinks the 4X4 isn't working.  There could be several reaons for that, and not all of them are serious.