Wobbles and wanders and shakes, oh my!
JK Freak
Joined: Apr 2013
Posts: 896
Likes: 5
From: Ventura, CA
looks like a bent axle shaft to me.
Replace them in pairs (obviously), most people go with the Ten Factory although I chose the G2 chromoly based on availability and a good deal from my local 4WP.
Ordered mine with new tone rings for the ABS sensors, and new bearings and retainer plates as well. Have the shop press it all together for you if possible.
Couple quick tips for the install;
1) jack one side of axle at a time, to eliminate diff fluid leaking out of the open axle tube on that side
2) you may need to rent a slide hammer to help pull the axle shaft out, mine needed it big time (but I have an 07 in the rust belt). Some guys can get them off by using the rotor itself, installed backwards with the lugs half way screwed in. You might need the little claw attachment also to remove the old bearing race if it sticks inside the housing, we did on one side of mine.
3) do yourself a favour before starting the whole job, check to see if you can loosen the 4x torque nuts that hold your bearing retainers into the axle housing. reason being, they are press fit, and if they spin, you will need to cut them out (and then replace the nuts). Nuts are about $5 a piece, most guys reuse them with loctite but you are supposed to replace them all as they deform when torqued. You will likely need a torch to cut them out, no way to get a grinder in there, maybe a sawzall at best. The nuts are an odd metric size thread pattern, have replacements available or you will not be able to install new shafts (if you had to cut any in the first place)
4) when installing, coat the outside diameter of the bearing race with a thin layer of silicon or maybe even RTV to create a better "gasket" for your diff fluid to stay inside the axle housing
5) torque for the nuts is somewhere around 50 ft lbs IIRC
6) you will probably notice that the brake pad retaining clips on the side with the play will be lacking lubricant from constant "brake action", good time to clean them up + apply some fresh silicon lubricant to the clips, guide pins and backs of pads at same time.
Following the repair, my brakes were noticeably smoother, and some of the vibes I was getting are now gone
Replace them in pairs (obviously), most people go with the Ten Factory although I chose the G2 chromoly based on availability and a good deal from my local 4WP.
Ordered mine with new tone rings for the ABS sensors, and new bearings and retainer plates as well. Have the shop press it all together for you if possible.
Couple quick tips for the install;
1) jack one side of axle at a time, to eliminate diff fluid leaking out of the open axle tube on that side
2) you may need to rent a slide hammer to help pull the axle shaft out, mine needed it big time (but I have an 07 in the rust belt). Some guys can get them off by using the rotor itself, installed backwards with the lugs half way screwed in. You might need the little claw attachment also to remove the old bearing race if it sticks inside the housing, we did on one side of mine.
3) do yourself a favour before starting the whole job, check to see if you can loosen the 4x torque nuts that hold your bearing retainers into the axle housing. reason being, they are press fit, and if they spin, you will need to cut them out (and then replace the nuts). Nuts are about $5 a piece, most guys reuse them with loctite but you are supposed to replace them all as they deform when torqued. You will likely need a torch to cut them out, no way to get a grinder in there, maybe a sawzall at best. The nuts are an odd metric size thread pattern, have replacements available or you will not be able to install new shafts (if you had to cut any in the first place)
4) when installing, coat the outside diameter of the bearing race with a thin layer of silicon or maybe even RTV to create a better "gasket" for your diff fluid to stay inside the axle housing
5) torque for the nuts is somewhere around 50 ft lbs IIRC
6) you will probably notice that the brake pad retaining clips on the side with the play will be lacking lubricant from constant "brake action", good time to clean them up + apply some fresh silicon lubricant to the clips, guide pins and backs of pads at same time.
Following the repair, my brakes were noticeably smoother, and some of the vibes I was getting are now gone
What he said!
Thread Starter
JK Newbie
Joined: Jun 2015
Posts: 24
Likes: 0
From: Winston-Salem, NC
So I got the rear axle shafts replaced with new G2 shafts. They didn't make a bit of difference on anything. 
I'm beginning to think something else is going on here. Something internal with maybe the transmission, torque converter etc. I've come to notice that these pulsating vibrations are only between 60 and 70mph while I'm accelerating. As soon as I let off the accelerator, the vibrations go away.
I'm at a loss here. If I had hope for anything fixing my issue, it was the axle shafts. Now I don't know where to go from here...
I'm beginning to think something else is going on here. Something internal with maybe the transmission, torque converter etc. I've come to notice that these pulsating vibrations are only between 60 and 70mph while I'm accelerating. As soon as I let off the accelerator, the vibrations go away.
I'm at a loss here. If I had hope for anything fixing my issue, it was the axle shafts. Now I don't know where to go from here...
JK Newbie
Joined: Apr 2015
Posts: 23
Likes: 0
From: Canada
Could be a bent axle housing itself? I am not sure how to check.
Maybe diveshaft vibrating itself, could be bent driveshaft itself or missing a balancing weight? You can pull them one at a time to check if better with them in or out. There are write ups for that. While they are out, you can also repack the rzeppa joints with fresh grease. Terraflex has a good how to on their website for their new high angle rzeppa joint.
Pinion angle could be off in the rear? There are write ups for that if you have rear upper adjust able CA.
Normally vibes while under throttle are driveline related.
Writing from cell phone so apologize for not scrolling up to see original poster details and specs.
Maybe diveshaft vibrating itself, could be bent driveshaft itself or missing a balancing weight? You can pull them one at a time to check if better with them in or out. There are write ups for that. While they are out, you can also repack the rzeppa joints with fresh grease. Terraflex has a good how to on their website for their new high angle rzeppa joint.
Pinion angle could be off in the rear? There are write ups for that if you have rear upper adjust able CA.
Normally vibes while under throttle are driveline related.
Writing from cell phone so apologize for not scrolling up to see original poster details and specs.
JK Jedi Master
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Two resources you might check.
Tom Woods driveshafts: there is some information under the 'JK' heading, and also in the Tech Info link at the top. Good reading on driveline related vibrations and harmonics.
Randy's Ring and Pinion: In Tech / Tech Help, scroll down to the end of the faq's to the section on diagnosing noises. (A howl or whine during acceleration over a small or large speed range is usually caused by... ?)
Tom Woods driveshafts: there is some information under the 'JK' heading, and also in the Tech Info link at the top. Good reading on driveline related vibrations and harmonics.
Randy's Ring and Pinion: In Tech / Tech Help, scroll down to the end of the faq's to the section on diagnosing noises. (A howl or whine during acceleration over a small or large speed range is usually caused by... ?)
Thread Starter
JK Newbie
Joined: Jun 2015
Posts: 24
Likes: 0
From: Winston-Salem, NC
I'm going to revive this thread as this is still and issue for me. As previously said it's a pulsing vibration between 60 and 70mph only when accelerating. As soon as I let off the gas, it goes away. Happens in 5th and 6th gear. My transmission fluid, differential fluids and t-case fluids have all been changed out recently.
Last edited by TinyTim93; Jan 29, 2016 at 09:04 AM.
JK Newbie
Joined: Jan 2016
Posts: 33
Likes: 0
From: Hagerstown, MD
i had a car with a beefy engine, it did that every time after i broke a motor mount (driver's side.)
i went through about 4 or 5...
eventually i chained the engine down on the driver's side and didnt break any more motor mounts
was on my old '68 dart with a 340, manual trans. i miss that old girl.
good luck
i went through about 4 or 5...
eventually i chained the engine down on the driver's side and didnt break any more motor mounts
was on my old '68 dart with a 340, manual trans. i miss that old girl.
good luck
JK Freak
Joined: Apr 2011
Posts: 719
Likes: 0
From: Lakeland, Florida
I'm sure you already checked but... is the wobble that you showed in the video still there? Since you changed the axles, have you check the disks for warpage? How about your rims? Tires?
I would jack the Jeep, start rotating by hand and give my dial indicator a workout just to be sure.
Good luck!
I would jack the Jeep, start rotating by hand and give my dial indicator a workout just to be sure.
Good luck!
JK Jedi Master
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
What spec did you use? The pinion should be almost inline with the output from the tcase. (1 or 2 degree lower than inline is what I see posted)
A few other people have indicated that their brand new shafts needed to be balanced. Whether they were knocked out during shipping or not done right to begin with, could be something to check.
Did you pull the diff covers to check the gear setup? One of the blurbs in the tech help sections I mentioned sounds similar to your experience.
And just to verify, you have driven without the front driveshaft installed, and you still have the vibes. And a tech has driven with the front shaft installed but no rear shaft, and the vibes went away? Did he get up to the same speeds you were at and let off the gas to try and replicate the issue?
And just to verify, you have driven without the front driveshaft installed, and you still have the vibes. And a tech has driven with the front shaft installed but no rear shaft, and the vibes went away? Did he get up to the same speeds you were at and let off the gas to try and replicate the issue?
Last edited by nthinuf; Feb 23, 2016 at 01:28 PM.