Shudder in Rear End. What could it be?

[silver4x4]

I have looked through a bunch of different threads and have not come up with a definitive answer. I have a 2002 explorer XLT and it seems that when I am turning either left or right at slow speeds, say under 10 mph it seems to shutter. This happens in the rear end. It just shakes and then if you get above 10 mph it seems to get a little better. I notice nothing in reverse and taking a corner at speed it does not do it. Any ideas. reading posts it sounds to either be a tranny, rear differential, or rear wheel bearings. Which one does it most sound like? Please, and what is my rough estimate on a cost for the most likely problem? I just bought the truck so I have no idea on the history but it seems to be well kept. Clean engine bay, exceptionally clean interior, decent body, no leaks, but that doesn't say much for things that people may not think about like trans flushes and such. Thanks for the help.

 

[BrooklynBay]

Did you check the rear U joint?

 

[silver4x4]

I am pretty good with cars but what and where would I be looking? The u-joint in the rear drive shaft or is there a u joint in the rear axles somewhere? I am sorry I am not familiar with where this would be?

 

[rrgone]

Do you have the LS rear end? 2WD or 4WD?

 

[silver4x4]

It is a 4wd and and the 4wd functions correctly. The tires are all matching. What is LS?

 

[BrooklynBay]

LS stands for limited slip. U joints are connected to the driveshaft on both ends.

 

[rrgone]

Limited Slip. Came standard with the tow package on the 2002 and 2003s.

The clutch packs can chatter and bind on these. If you have the LS I would suggest changing the rear differential fluid and adding a can of friction modifier and see if that helps. There is a TSB on this issue but I have lost my copy - someone help please???

 

[BrooklynBay]

http://www.explorerforum.com/forums/showthread.php?t=157872

 

[silver4x4]

I don't know about the limited slip but how hard is it to change fluid and add the friction stuff?

 

[BrooklynBay]

You have to open the plug, and pump it in.

 

[k4mjk]

i have an 01 sport and i have a pretty loud rear end whine also i just changed the front hubs and plan on doing rear bearings has anyone done the tsb change out themselves? how much do you think the fluid swap will help? i have changed it before but i used the 75 90 the manual says.

 

[rrgone]

And here's another TSB link: http://www.fcsdchemicalsandlubricants.com/supplier/tsb/05126.pdf

These are all for the famous singing rear end though. Isn't there another one that specifically describes the LS differential shudder? Seems to me there was a TSB for that and the fix was to change the fluid to full synth 75W-140 and add a can of friction modifier. Those instructions are also given in the TSB links here, but these are really about ring and pinion gear whine.