Jeep Newbie-Front diff questions

[Bgann92]

So for starters my front hubs wont unlock, just realized this! Tried reversing, wont unlock.

Now im getting a grinding and vibration in 4wd. Mechanic says I need a new axle, any
Advice is appriciated.

 

[xjmarc]

If it's for the 98 TJ you have listed it doesn't have hubs to unlock unless someone swapped in a different axle. Give us a little more detail and we may have some places for you to start looking. Rarely ever do you need to replace the whole axle but sometimes it's cheaper in the long run.

 

[Bgann92]

Yes its the Jeep, its a 98 Sport edition Wrangler bone stock! I was under the
Impression it has auto locking hubs, but I dont know anything about Jeeps,
my real question is do I have to replace the whole axle, or can I just do new
spider gears and bearings?

 

[superj]

the trans is what locks, the front end is always engaged. pop the diff cover off and check it out. that is the best way to know whats going on

 

[superj]

let me clarify as that sounds funny /\

the front axles are always engaged to the differential as jeep got rid of the actuator in the early 90s. the tcase is what engages the 4x4 to the front. when you drive, your front drive shaft is always turning from the front but doesn;t get any power till you put the tcase in 4 hi or 4 lo. so, if you have grinding, it might not be that it is stuck in 4x4, it might just have something in the bearings

 

[Bgann92]

the trans is what locks, the front end is always engaged. pop the diff cover off and check it out. that is the best way to know whats going on

So thr front shaft is always spinning? He popped the cover off
Theres ball bearings inside the gears. Any ideas?

 

[Bgann92]

Its not locked in 4wd, put it up on the lift, front wheels only spin in 4wd.

 

[xjmarc]

There shouldn't be any ball bearings in your front axle. The carrier and pinion have roller bearings but they are cylinder shaped not balls. Can you pull the front cover and take some pics of the ring gear and spider gears? Also with the cover off and a wheel jacked up spin a tire and see if anything is binding. May want to also check for play at the yoke, see how much it will spin with both tires on the ground and if it moves in and out. Then let us know what you find and we'll go from there.

 

[superj]

the front axles are always locked with the wheels but not always locked with the trans. the front is always ready for 4x4, when you shift into 4 hi or lo, nothing on the front changes, only the transfer case changes. thats what i mean by locked

 

[ljrubitm]

Bgann92,
You said "there are ball bearings in the gears". It could be that the bearing for the pinion took a crap.

 

[Bgann92]

There is about half an inch of play at the yoke, cant take off the diff cover at the moment. What does the play jn the yoke mean???

 

[xjmarc]

Play turning or in and out. Turning would be a backlash issue, in and out, which would let it turn some as well, would be pinion bearings and if they are too bad good chance the gears are gone as well. If it's stock you'd come out cheaper replacing the axle than gears, if the gears are gone bearings are pretty cheap. Low pinion D30s from TJs and ZJs go for 150 and less around here. You'd just need to match the gear ratio with the rear axle.