Need help with rear Diff chattering
 

Hi, i have a lifted 1997 4x4 4.0l V6 Ranger, here's my problem. I was driving the other day and all of a sudden my rear-end starts chattering really bad, the whole truck was shaking. I stopped and looked underneath and i didn't see anything wrong i checked the drive-shaft and nothing on the outside looked broken. long story short my dad told me it was the rear diff, and in limited slip diffs if the fluid is low, the "friction plates" rub together, but thats all i got from him.... lol so i need some help if anyone can explain this to me better so i can fix it, it would be greatly appreciated. I just wanna drive my truck again.

I doubt your Rear end is low on fluid unless something has been leaking, and you'd notice it.
You may not even have a limited slip, on the inside of the drivers door, under the "axle" word on the door tag, tell me what the number/letter combo is.
Axles just don't "lose" fluid, either the axle seals are blown, or the diff cover is leaking.

Here's my experience...
This happened on my 98 AWD Explorer at 110,000.

Not as dramatic as your situation but very similar and was able to resolve it completely.
The rear end would chatter. The whole truck would shake. I had no clue what it was. I actually thought it might have been something on the front end because it only happened during low speed turns. The dealer told me "I needed to replace the entire rear end", I was like, okay give me my truck back please.

I did a lot of research on the explorer forum (and posted about it). I drained the rear end diff, added Amsoil gear oil and their "non-slip" additive that goes in diffs, it comes in a separate very small bottle. After a few hundred miles the chatter went away COMPLETLY! And the differential was 100% fine until I sold the truck at 215,000 miles.

It would def be worth your time to try this. Will prob only take you less than an hour and maybe $100 in "parts".

I still have the products I used and can list the Amsoil product numbers when I get home on Saturday if you need them.

In a nut shell, you remove your rear diff cover. All the fluid will come out.
Clean the surfaces well. Apply proper gasket to your cover. Reinstall and properly torque. Add the gear oil. Then add the additive and reinstall the full plug. There are lots of walk throughs on this and how to properly apply the gasket on the web and YouTube and stuff.

Thanks, that's exactly whats going on, on the low-speed turns it chatters so i will give it a try thank you.

just as a follow up and FYI, here is the link i was able to dig up when i worked through the issue on my truck

http://www.explorerforum.com/forums/...d.php?t=178145

the key was adding in the "slip lock additive", i think i used 6oz, they come in 4oz bottles

You need the additive on any Limited slip. So, if it was changed and the additive wasn't put in, you'd know it in about 1000 miles.

Thanks guys i'll let ya know how it goes.

Sorry it's been a while i ended up fixing the problem it was my U-joint in my drive shaft where it connects to the DIff, It actually ended up breaking but completely solved the problem. thanks for all the help, i ended up have to replace my rear axle seal's as well. I had diff fluid getting into my drum breaks.