I have the LSD and it has always worked great. Today I was in the farm pit and drove really slow up an icy hill just to see how things were working. The passenger side started spinning and I stopped moving. Then I slid back a bit. I really couldn't believe it. So I rolled back a bit and slowly drove up again and the passenger side broke free and spun.

Why the change? I haven't serviced the rear diff for about 50,000 miles and do not have an additive in it. Should I have been moving faster or is there something else I could have done to get both rears spinning? It has always worked in the past.

 

It's normal. Only a true locker will keep both tires going the same speed all the time. The LSD will usually keep both tires going but if enough pressure is put on them (one tire dry ground and one on ice) like it sounds you did, they will let the tire on ice spin. Had you been going a little faster it may not have happened.

 

Try braking some while going up the hill. If it takes more than about three times more torque to turn the "dry" wheel than spin the "icy" wheel you'll spin the icy one, as you found. Torsen LSDs can split torque about 3:1 between the wheels.

 

Remember, the "L" stands for "Limited". If it was no slip, it would be NSD.

 

Mine does the exact same thing always has and it makes me madder than hell. I too have an uphill incline to my place in the sierras and the truck will not go up hill with one side on ice and the other on dry pavement. I've always had to lock into 4WD. And I've tried tapping and playing with applying the brakes... it doesn't help still rolls backwards down the hill while the wheels are spinning. Bring back DANA.

 

thinI think the advice is to apply the parking brake slightly to bias the differential some.
Why it changed, I don't have a clue!

 

LSD's really are not very good, they are cheap and appease the masses so that is why they are supplied.

 

When I first got the truck I towed my fiver up an icy road in Georgia with one tire on pavement and one on glare ice. It never spun a bit. I was completely impressed. Then I tested in hundreds of times on gravel / asphalt, mud / dry, this is the first time it has ever let me down.....

 

The LSD is not offered in the AAM axles. You get the trac-rite diff. This is a urinary deficient replacement for the much better LSD. There is no clutch material in this unit. It is metal to metal. The diff fluid must be changed and the axle/diff needs to be cleaned at each fluid change.

 

LSD stands for Limited Slip Differential. LSD is not a brand name or a specific type, it's a generic term. There are a number of different types: clutch, worm gear, locker, wave lock, etc.

The Dodge trucks are available with a worm gear type of diff, providing pretty control of torque differential with good durability. Proper adjustment is pretty important. and, over time, that adjustment can waver from perfect, so it doesn't work like it used to.

There are no clutch packs like in a chevy Positraction or ford Traction-Lock.

A worm gear is a bit different than a clutch type or a locker. If you lose all traction with a worm gear, all of the torque gets sent to the side with zero traction. Sometimes that's a good thing, and sometimes not. When that happens, a little brake application will shift the torque back where it belongs.

I use something similar in my race car with very good results.

 

Not referring to prior post, but this thread in general. Reading these types of threads makes my head spin with the complete lack of knowledge people have about their trucks or general diff technology and terminology...

And why in the world people are feathering their E-brake is beyond me... the fat pedal to the left of the skinny pedal is the one you're supposed to be feathering.

 

Referring to the prior post, not the thread in general:

Actually, feathering the e-brake does exactly what you want to do.

By feathering the "fat pedal", you're apply brakes to all wheels, and if the front wheels have good traction, they will keep you from moving (and moving is the goal of this whole exercise in the first place).

Further, it takes a bit of practice to correctly feather (while applying gentle throttle at the same time). Most drivers don't practice this skill until they really need it, and by then it's too late.

By applying e-brake, you are ONLY slowing the rear wheels. And you have more exact control of the brake by applying more braking pressure just 1 click at a time.

I'm sure it seems crazy to you, but the "complete lack of knowledge people" got it right this time!