04 Liberty Rear Diff

[k2damfc]

04 Liberty Rear Diff Help Please

I have an 04 Libby thats been causing me troubles. A while back I noticed that the tube to my front diff was cracked. Yay!! Then after a generous dose of ghetto fabulous bracing, then my rear diff goes up. The outer pinion bearing was shot, actually made 1 of the rollers disappear, realized I needed a whole new set, Pinion & Ring, bearings and seals. I replaced it. A huge pain for a first timer into that sorta thing. However not being able to do the inch pound test for removal of the pinion, I can't figure that part out when replacing, so kinda went to the minimum at 210 ft/lbs. Which is also a pain on the ground. Anyways went thru, everything seems to be running solidly together, however the actual diff inside with the holding bars, has these threaded donuts (best description I can think of) obviously used for adjusting left and right play of the diff. Tried to make those as tight as possible. All is said and done and now the damn things making a low grrrrrr type of a noise. It almost sounds like the diff needs to be moved a little bit. It almost sounds like the small ribs of the pinion rubbing with the ones on the gear. (Fresh pinion and gear has the ribs, not wear and tare) When I had the whole thing disassembled the axle bearings looked fine. A little rust dust on the right side, and some lube on the left but thats it. I even lubed up both sets with fresh 75w90. Kinda stuck with very limited funds, and no ride. Don't wanna damage the thing anymore after puttin $500 in just parts into just this project. Any words of advice. Can't really get it anywhere. Dealership is closest but don't wanna drive for to long or pay too much, there's an actual 4x4 spot a little ways away, but once again don't wanna blow up everything that i've done.

 

[k2damfc]

Just took it for a cruz around the block. Seems to not make much noise goin up hill as it does down. When I stopped it took my 4-way (Stethoscope) and set it to a couple places on the diff while it was jacked up and in Drive. The noise itself sounds almost like mis aligned teeth with the pinion and gear. Any idea's how to set this straight?

 

[JMSMN]

Did you check backlash in the gears. Do you have dial indicator. If so secure the pinion so it cant move, put the dial against the ring gear and zero it, then move the gear to see how much movement it has back and forth. There is a spec for this and dont know what it is. Also, I would put some grease on the ring gear teeth, then run the two gears together to see where they make contact with eachother, should be near the center of the ring gear teeth.

 

[jnaut]

Just took it for a cruz around the block. Seems to not make much noise goin up hill as it does down. When I stopped it took my 4-way (Stethoscope) and set it to a couple places on the diff while it was jacked up and in Drive. The noise itself sounds almost like mis aligned teeth with the pinion and gear. Any idea's how to set this straight?

You're a real man (or woman) for doing your own repair. Mine appears to have the exact same problem. I'm still driving with it because the repair bill starts at $650 and went up from there. (one shop wanted to start @ $1,100 and go up from there). Plus I looked into doing self repair, and I'm too novice to take the risk. Too many micro adjustments and stuff to go wrong if you don't get it right the first time. nono.gif

As soon as I get mine paid off I'm taking it in for the repair. Mine sounds like I'm being followed by a moped or someone is behind me with a leaf blower.

I spoke with a mechanic from Dean Transmissions here in Seattle, and he told me that the Chrysler 8.25 is known to occasionally have this problem, depending on how tight the tolerances were set to at the factory. "Luck of the draw" is what he said.

 

[JeepJeepster]

Before you spend that much $$ and time on an axle I would just buy a used axle. Takes all of a couple of hours to change them out.

 

[Idaho08KK]

It sounds like you don't have any backlash between the ring and pinion. When replacing the ring and pinion, you must first install the pinion and bearings, then crush the crush sleeve until you obtain the proper rotating torque.
Next, you install your carrier with new ring gear, and use the side adjusters (threaded donuts) to obtain the proper gear pattern and backlash. When that is all done, you want to check the total rotating torque of the new ring and pinion.

I have literally rebuilt hundreds of differentials over the years, but I can understand it being intimidating for a newby. I remember the first couple that I rebuilt, and being nervous about it. I can do them in about 3 hours now.

If you would like all of the specs- pinion rotating torque, backlash, total rotating torque, I can get them for you. Just let me know.

Just from reading your first post, it sounds like you have some problems. It sounds like you have no backlash, possibly due to the way you tightened the side adjusters. There is actually a torque spec for the side adjusters, and once you have them where you need them for proper backlash, you need to torque them and recheck your gear pattern with gear marking compound.

 

[n8fis]

Funny, I just took my 04 into a ****** shop today for
what I thought was too much backlash. Mine is a manual
and you can hear what sounds like too much backlash.

I got a call from the ****** shop a few hours last. They
said, yes there is a bit too much backlash but for the cost
to fix is not worth it................. yet. In other words, live
with it till it gets lot worse and then look for a used rear
end in a bone yard.

Maybe a recall? I doubt it but who knows...

 

[J-Thompson]

find some one who knows how to install gears and lockers PROPERLY and let them fix it
I can pull my ARB that is already set up and do what ever I need but I am not about to pretend I know how to install a gear set properly