i need to replace these asap....ive never pulled a diff apart....any suggestions or advice would be appreicated....an would diff bearings being bad cause a thud noise when turning but not when moving, ive gota thud sound which feels to be under the gas pedal when i turn but doesnt make noise moving ....just when i turn...its driving me crazy

 

have u checked the ujoints in the front axle? ive also had sway bar links and links do that also when wore out. just a thought.

 

He's right. My Dana 30 usually needs new u-joints every 2-3 years with the big tires. sounds just like your description.

 

Would the ujoint actually cause the thud popping noise not moving ..just turning the wheel ...i figured if it was them id hear it while driving but i dont...

 

Turn the wheel to the lock. Take a pry bar and insert it in to the spindle below axle shaft. Try prying up gently at first, on shaft. You should be able to tell if you joint is at fault.
And yes. Depending on how the u-joint is orientated, just turning the wheel will make the joint bind and pop if it's gone to the dark side.

 

Il check that my next day off...i also forgot to mention i got bout 1/2-3/4in of play in the front shaft ...not up in down play like a bad ujoint but its rotating that much...is that bout the normal play?

 

I've got about that much play in my front shaft as well. Unless the 4wd is engaged. Then there's no play.

I'm guessing from your name your in WV? What part?

 

ok im just trying to find this noise i can feel it on the floorpan under the brake pedal.... charleston area

 

If it does it while parked, track bar at axle or frame bracket is loose or a control arm bushing is shot.
Your LCA and UCA are pretty much under and above the pedal FWIW.

My money is on either bad track bar joint at the frame bracket, or loose track bar at the axle (pita to get tight enough) or MOST LIKELY the 4 bolts holding the track bar frame bracket are loose.
You won't be able to see it move and it'll seem tight but they aren't as ridiculously tight as they need to be.
Loosen them 1/2 turn first, the CRRRRRRAAAAANK them with an 18 inch breaker as "body weight +" tight as possible, and I bet the noise goes away.
I treat mine like a pinion nut: 190lbs+ minimum.
I chased the same noise you describe for a year, and thought I got the TB bolts tight enough till I used the breaker and voila, no noise again.

999,999 times out of 1,000,000 it's TB, LCA, or UCA bushing related if not moving. Has to be an attachment point under load popping if not moving. Not likely driveline related.

 

Nice set up!

 

il check that out as soon as it quiits raining here....i need a garage...

 

Thanks CC. We've only had it for 13 years. Bought it new back in 99. Always had an XJ since 86.

I'm for huntington originally. Are you still using the stock control arms and track bar?

 

heard that im actually in st.albans area...little closer to htown...yea right now its not lifted.. im basically goin threw everything making sure its right before i put my lift on

 

Ok. I had a problem with track bar mount on the axle. There's a concealed nut held in place with a tab. Mine was broken but didn't seem like it till I started tearing it apart. Depending on the amount of rust, plan on replacing that nut. I made a new one Out of stainless for the future. That could be a culprit too.