MoparFins

Techical Discussions => Tech- - DRIVE TRAIN => Topic started by: Brian on July 06, 2008, 08:48:24 PM

Title: Rear axle noise....
Post by: Brian on July 06, 2008, 08:48:24 PM
Anyone???
Title: Rear axle noise....
Post by: Steve on July 07, 2008, 04:42:47 AM
If they're making noise it's too late to repack them
 
Drive the car down a winding road.  If the noise increases on a right or left turn then you have a bearing problem.  Same thing in the front.  If it doesn't change, it may be a carrier problem.
 
Check your oil level
 
May as well do a pinion seal while you're at it
Title: Rear axle noise....
Post by: Brian on July 07, 2008, 06:42:21 AM
I fogot to ad when I first posted this but Steve jogged my memory.  When I changed the pumpkin from the 2.76 to the 3.23 the axle bearings were VERY DRY...and they looked a little cooked...I repacked them and reinstalled.
 
So if they were already dry and a bit cooked I guess new axle bearings are in order??? 
 
I should just do them anyway since I will be putting on about 1000 miles on holiday next week.
 
 
Title: Rear axle noise....
Post by: Steve on July 07, 2008, 09:54:04 AM
Brian
 
Go with the Green bearings.  They are sealed (if I recall right) and you eliminate the adjuster.
 
Is it a whining sound that changes as you torque and untorque the rear? 
Title: Rear axle noise....
Post by: Brian on July 07, 2008, 12:09:24 PM
I moved my ear as close to the axle bearings as possible and could hear nothing...so I'm pretty certain that it is the third member that is making the noise.
Title: Rear axle noise....
Post by: Steve on July 07, 2008, 12:23:04 PM
And now you have ========= on your forhead huh?
Title: Rear axle noise....
Post by: Brian on July 07, 2008, 12:30:39 PM
Quote from: POLARACO
And now you have ========= on your forhead huh?
 
(http://www.moparfins.com/forum/smileys/smiley36.gif)(http://www.moparfins.com/forum/smileys/smiley36.gif)(http://www.moparfins.com/forum/smileys/smiley36.gif)
 
I was being EXTREMELY carefull....lot of moving parts I didn't want to meet....(http://www.moparfins.com/forum/smileys/smiley2.gif)
Title: Rear axle noise....
Post by: Steve on July 07, 2008, 01:07:43 PM
 I hear ya
 
Flap Flap Flap Flap
Flap Flap Flap Flap

Title: Rear axle noise....
Post by: Brian on July 07, 2008, 03:50:37 PM
Quote from: POLARACO
 I hear ya
 
Flap Flap Flap Flap
Flap Flap Flap Flap
 
Is that the noise your head makes when stuck under the spinning wheel.....(http://www.moparfins.com/forum/smileys/smiley5.gif)
Title: Rear axle noise....
Post by: Steve on July 07, 2008, 06:06:18 PM
No when you get you belt caught in the drive shaft.  Floor boards hurt!

Is that like a howling sound or does it have a grinding sound to it that changes as you change the torque on the rear with the engine.  Coasting, up hill, down hill, match engine speed to vehicle speed on flats. . . .  That's what I am trying to find out.



 
Unfortunately, they make all kinds of noise when up in the air like that.  Hard to tell that way.  Did you check the oil level while it was up?
 
 


Title: Rear axle noise....
Post by: Brian on July 07, 2008, 08:35:34 PM
The oil level is fine...I put in the recommended amount...as per the FSM... when I swapped pumpkins.
It's defenitly not a growl...more like a tinny whine, almost sounds like the drum is barely rubbing the backing plate...it does change in volumn and pitch a bit when you feather the gas.
 
Coasting doesn't seem to effect the noise...still there.  Up and down hill seem about the same and on the flats cruising nicely it's just a constant noise.
 
I haven't tried the cornering thing yet...maybe tomorrow evening I can get a little drive time.
 
 
Title: Rear axle noise....
Post by: Steve on July 08, 2008, 04:07:56 AM
Now you got me on that one.  Without hearing it, hard to say.  But this discription makes me think i t may be just normal for that rear.  Don't hold me to that. . . .(http://www.moparfins.com/forum/smileys/smiley2.gif)
Title: Rear axle noise....
Post by: Brian on July 08, 2008, 04:09:52 PM
Quote from: POLARACO
Now you got me on that one.  Without hearing it, hard to say.  But this discription makes me think i t may be just normal for that rear.  Don't hold me to that. . . .(http://www.moparfins.com/forum/smileys/smiley2.gif)
 
Someone suggested maybe the pinion bearing is making the noise??
 
I tried the throwing the car back and forth today and again it really didn't seem to make any difference that I could hear....definetly didn't get worse or go away so I guess I'll leave it as is and just drive it until something breaks....(http://www.moparfins.com/forum/smileys/smiley2.gif)(http://www.moparfins.com/forum/smileys/smiley1.gif)
 
OH BTW this is a junkyard score 3.23 in a 489 case I picked up years ago for $50...so this is the first time it's run in who knows how many years.
 
 
Title: Rear axle noise....
Post by: Steve on July 08, 2008, 05:56:18 PM
That's the noise I was looking for in your description.  Either mis matched gears or a bad pinion.  The change should change some as you torque and untorque the rear while driving.
 
But mis matched gears would give you a howel
Title: Rear axle noise....
Post by: chuck lowe on July 09, 2008, 03:33:56 AM
i tried that up in the air deal once------like steve said-you hear all sorts of noises------with no preasure on parts it's real easy for sound to be telegraphed from part to part-------i had a wagon once that was making all kinds of sounds from the rear wheels-i had it checked by three diff.  places up and down---------------------------------it ended up being a belt on the right rear tire being broke------there was no shake-just all sorts of noise------that tire was balanced and still wasn't caught-----it was so minimal you had to look and feel real close------the point i'm trying to make is that it could be about any part------go with your first thought-maybe you'll be lucky-----------------------------later
Title: Rear axle noise....
Post by: Steve on July 09, 2008, 05:27:30 AM
See now Spanky there strapped himself to the axle and had his wife drive the car around.   She wanted to get rid of him anyway. . . .(http://www.moparfins.com/forum/smileys/smiley36.gif)
 
Just kidding Brian.  I've done it too.
Title: Rear axle noise....
Post by: Brian on July 11, 2008, 09:35:24 PM
Quote from: POLARACO
That's the noise I was looking for in your description.  Either mis matched gears or a bad pinion.  The change should change some as you torque and untorque the rear while driving.
 
The noise doesn't change much when under load and free wheeling...just a slight change in pitch.
 
 
Title: Rear axle noise....
Post by: Steve on July 12, 2008, 04:53:33 AM
Is it like  howel or something else?
Title: Rear axle noise....
Post by: Bill Mounteer on July 12, 2008, 07:48:51 AM
Brian, when you installed the pinion and adjusted the inner shim pack to get the correct gear lap, did you use bear blue so that you cold see the overlap and exactly how the contact surface looked?

(http://www.moparfins.com/forum/attachments/25/155_0308_gear_22_z.jpg)

If the inner shim pack shifted after you installed the outer shim pack and torqued  down  the pinion nut,  your overlap could have shifted. This will give you a whine. Also since the ring gear was a used one, did you use it's companion pinion gear? If not they could make funny noises until they wear in, but you may have to re-open it to adjust the shim packs again.  I've done a few of these swaps over the years on my Scout 4x4 and found installing used ring and pinion gears are tricky to get them to run quietly because you have to find, by trial and error, where they overlapped before. If you are off a bit, the gear surfaces will make noise as they wear in the "new" overlap position.

I also used 75W140 gear lube along with the recommended limited slip gear additive. I think the spec oil is about 75W110 but found it was noisy in the summer so I used the thicker stuff year around.


Title: Rear axle noise....
Post by: Brian on July 13, 2008, 09:06:13 PM
Holy moly Bill....I aint that brave yet!!(http://www.moparfins.com/forum/smileys/smiley2.gif)(http://www.moparfins.com/forum/smileys/smiley4.gif)
 
This is a complete pumkin/ 3rd member swap so the set-up is what it was...could be good could be bad....(http://www.moparfins.com/forum/smileys/smiley5.gif)
 
 
Title: Rear axle noise....
Post by: Bill Mounteer on July 13, 2008, 10:12:00 PM
It just looks complicated, but really its not. All you need is some bearing blue, some different thickness shims, a torque wrench, beer and patience.  When you get low on patience, add more beer. (http://www.moparfins.com/forum/smileys/smiley4.gif)

The inner shim pack simply positions the pinion to get the best contact and the out shim pack sets the preload. I forget the actual preload figure, you just turn the pinion using the torque wrench and see what the reading is to just turn the gear. I always use a beam type since you just read the lbs as the pinion turns. Don't think a fancy click type would work in this application.

So if you decide to really check yours out, put the rear axle up on stands, pull the axles out a couple inches, drop the drive shaft and check the preload. I'll bet it's loose as a goose. If so you'll have to reset probably both shim packs because the inner shims get pretty beat up if the preload is too low. All it takes is patience and of course lots of beer!(http://www.moparfins.com/forum/smileys/smiley36.gif)


Title: Rear axle noise....
Post by: Brian on July 14, 2008, 12:00:26 PM
I'm sensing a theme here...More Beer....More Beer....More Beer....(http://www.moparfins.com/forum/smileys/smiley2.gif)(http://www.moparfins.com/forum/smileys/smiley36.gif)
Title: Rear axle noise....
Post by: Steve on July 14, 2008, 01:43:42 PM
Quote from: thrashingcows
Holy moly Bill....I aint that brave yet!!(http://www.moparfins.com/forum/smileys/smiley2.gif)(http://www.moparfins.com/forum/smileys/smiley4.gif)
 
This is a complete pumkin/ 3rd member swap so the set-up is what it was...could be good could be bad....(http://www.moparfins.com/forum/smileys/smiley5.gif)
 
 
Yeah, but not that expensive to fix
Title: Rear axle noise....
Post by: Bill Mounteer on July 14, 2008, 04:02:04 PM

Quote from: thrashingcows
I'm sensing a theme here...More Beer....More Beer....More Beer....(http://www.moparfins.com/forum/smileys/smiley2.gif)(http://www.moparfins.com/forum/smileys/smiley36.gif)
Beer is the natural companion to duct tape! (http://www.moparfins.com/forum/smileys/smiley4.gif)

With enough duct tape and sufficient beer it's possible to turn a rusted out beater into an unbelievable master piece - at least until the beer wears off! (http://www.moparfins.com/forum/smileys/smiley4.gif)