How to tell if rearend is open or limited

[jlfq2]

I am trying to find out if the rear end in my 05 dually is open or limited.I believe the axle code on the door says limited but if one side is in the snow only it will spin.If i do a burn out on dry pavement they both spin.If you jack it up and spin one wheel the other spins the opposite direction.I have the cover off right now changing the gear oil.Can I tell by looking at it if it is a open rearend?
I can post a pic later.I was hoping someone had a pic or could tell me what to look for.
Thanks,Jeff

[shustack]

Their should have been a tag on the rear diff cover that tells you what gears r in it and weather its a open or limited rear. I forget what the mark for open is but i do know the limited should say like 3L73 or 4L10 i believe or something to that affect. Unless you tag is gone. Than i have no clue.

[jerg_064]

Should have some type of clutch system if it's limited.......If you can roast both sides on pavement though then it's certainly not open.

Keep in mind that with limited slip it's a partial torque resistance transfer, say like 1/3 of the torque of the slipping tire will be transferred to the traction tire or something like that. So if one tire is spinning with no resistance like you may have ran into on the snow/ice then it won't push power to the other. Next time try applying some tension via the e-brake and it should pull out. My explanation here may have some error in it, been a while since I researched LS diffs.

[TheFordman87]

That is correct if you apply tension wih parking brake or even regular brake just a bit it should help it start spinning both. Now heres the kicker LS diff will get wore out and the clutches won't hold as good after time. So what you need to do then is either put new clutches or shimm the clutches to hold tighter. If you do a search on here you might find a right up how to shimm clutches tighter. If not make a new thread someone will explain in full detail.

Btw it shouldn't be very much at all for shimm plates and to do it yourself.

[AXELRICK]

Ive been wrong before, but I thought open rearend and tires spin in opposing directions. Limited slip and both spin same direction off the ground. I have the build sheet on my and it lists limited slip. Both mine spin same direction on hoist.


Rick

[TheFordman87]

That is true on how the tires spin. But it won't spin both back tires while power braking it. I know there is an answer for why it's doing that. I will have to ask my dad cuz we discussed that very matter years ago.

[HeavyAssault]

The door sticker will tell you. Look for the area labeled AXLE ...a number with an L is a limited slip rear diff. More than likely a KR will have the limited slip with 3.73 gears.

[jlfq2]

Well it is a limited slip axle just like the door code and axle tag show.I guess maybe to much friction modifier was added or the clutches are wore out.I have read about restacking the clutches to make it lock up better.Maybe I will try that when I have more time.Thanks for all the replies.

[GregsSD]

It's most likely just wore out!
My 05 limited slip rear end only worked good for the first year or two, you just need to have some new clutch discs installed.

[still runs]

can you put new clutches in with out tampering with the lashing ??? setting lashing is just a pain in the a ss