Rear end question

[71 Blazer]

I recently went mudding in my 71 Blazer and noticed at one point when I was stuck that one of my rear tires wasn't spinning as fast as the other one. I know that I have a posi rear end because I have jacked up the rear and both tires spin in the same direction. What would cause this? Is it just worn out? Do I need to add something other than gear oil? I haven't pulled the cover yet so I have no clue what is in their.

 

[Masiony]

limited slips do just that. they slip. they are no where near what a true locker is off road. it may be worn out, but it may be that the traction difference between the two tires was too great for even a new LS. my suggestion, if you want good traction, just buy a detroit.

 

[71 Blazer]

Correct me if I am wrong, but in a limited slip rear end the tires would rotate in opposite directions when jacked up, mine spin in the same direction, which means I have a locker, right?

 

[dyeager535]

No, limited slip means just that..."limited" in how much "slip" they allow by either axle. It's spring pressure on clutches that binds them together, which means vehicle weight, load, traction, etc affect how well they work. Limited slip and posi are the same thing. Seems to be getting more widespread that people understand that now.

An open differential (no traction aiding device, which is stock/base for our trucks) is typically what spins the wheels in opposite directions. So does the gov-lock, but we won't go there.

A locker physically locks the two axles together so there is NO slip between the two axles.

 

[Masiony]

Correct me if I am wrong, but in a limited slip rear end the tires would rotate in opposite directions when jacked up, mine spin in the same direction, which means I have a locker, right?

an open diff spins the tires in opposite directions because the carrier doesnt rotate while the side and spider gears rotate around inside the carrier. a LS usually spins them the same way because there is less resistance to spin the whole carrier than there is to force the clutches to move against each other.

A locker physically locks the two axles together so there is NO slip between the two axles.

not quite true. lockers such as a detroit can allow the axles to "slip" but i wouldnt call it slipping, more like "ratcheting". when you let off the pressure the mechanisms in a detroit and similar will "unlock" the locker to aid with turning. but as soon as there is resistance to the carrier (either gas or heavy decceleration) it will lock up again. spools are lockers that physically lock both shafts together 100% of the time.