drivetrain/wheel bearing grinding sound?

[Sacredgroove]

something new: hiss from gas tank area

i was doing some highway driving(cj7 258 t5)
had a few incidents were it felt/sounded like the jeep was running over stretches of the ridged road they use on the sides of highway to wake people up if they wander over...it also happened once at very slow speed in a parking lot.
wheel bearings perhaps? i know my pinion bearing is close to shot,could that be the culprit? if so,what kind of labor charge would i be looking at to do a pinion bearing? its the amc 20. thanks for any insight!

ps-if it is the pinion bearing,should i look into doing anything else simultaneously to save labor later?

 

[olyeller]

i'm in the process of changing out my front wheel bearings now. i had an intermittent roaring noise that sounded like the jeep was gonna fly apart. in the past, i've just tightened the spindle nuts on the front spindles and the noise would go away for a few months. you can check for looseness or wiggle in the front wheels by jacking the front up and pushing/pulling on the front tire. yesterday, when i tightened the spindle nuts, the driver's side front wheel would still wiggle, so i went and got new bearings.

 

[Snitty]

if you are having the pinion bearing changed.. might as well get the bearings and inner seals in the axle changed out too, and if you plan on regearing... now might be the time since it all has to come out anyway

 

[Sacredgroove]

drove it some today and still cant put my finger on where the problem is due to it being so loud with softop etc.. at the speed problem occurs. it feels like a bearing or something is trying to seize but lets go and returns to normal after 5-10 seconds. only happened a few times over 50 miles or so. if its pinion bearing i guess it would be a good time to add a locker too? anyone have a rough estimate on labor charges for putting in new bearings,locker etc? (amc 20 rear)

 

[Snitty]

new bearings and a locker.. for labor should be no more than 3-4 hours at a moderate garage... can be done in about or under 2 hours with an experienced garage

 

[Sacredgroove]

that sounds good! I was expecting 5-6 hours labor for all that. do they have to pull the whole axle out or can they do the work leaving it on the jeep? anything else i should upgrade while its apart? ill probably go ahead and have the moser one pieces put on and have the drums and wheel cylinders checked out as well.

 

[Snitty]

the axle shafts will have to be pulled.. but the axle tube will stay on the jeep

 

[Junkpile]

If you are going to have the axle apart anyway, the first thing to do would be to upgrade to one piece axle shafts. The carrier isn't really a weak point in your axle, so a locker that installs inside a factory carrier can save some money and help offset the cost of the shafts. But if money limits mods, take the one-piece shafts before the locker....because as soon as you add the locker, you're gonna have to upgrade to one piece shafts anyway.

 

[Sacredgroove]

Set of 5 Almost-New BF-Goodrich All-Terrain Tires (31x10.5)

it seems to happen when i hit a bump,like something is trying to sieze but it lets loose after 5-10 seconds.slowing down or speeding up seems to clear it up quicker and it feels like rear drivers side wheel but hard to tell for sure. doesnt slow me down,or pull to one side when it happens either,just noise and fast vibration.
thanks for the axle insight everyone,not sure if thats where the problem lies but in near future axle needs adressed regardless.

 

[LBR]

Hi sacredgroove
have you jacked up the rear, set jack stands under the axle, transmission in neutral, then twisted the driveline by hand and watch the rear u-joint to make sure that it isn't binding? The driveshaft should twist nice and smoothly - if you feel a resistance anywhere then it could be the ujoint or your pinion as you had mentioned. I see your running a 4" lift and if the rear driveshaft angle is too severe then maybeeeeee... I have a cj with 4" lift, dropped transmission/transfer mount, and angle shims between the leaf and rearend and STILL had to do some grinding on my driveshaft to clear the u-joint at the 2 interference points on the 360 degree revolution...also have someone "drive it" with rear wheel in air and have a look/see at everything LBR

 

[redrooster]

If you think it is a bearing then you need to locate the problem and change the bearing. If the bearing locks up and spins the race in the housing, then the housing will be toast.