Was at the dealer getting the oil in my 2nd gen changed. Struck up a conversation with a fellow that had purchased an 04 4x2 dually 3500 new 2 days ago. He said he brought it in to have them look at the limited slip. He was on his ranch and had one set of wheels on hard ground and the other side slipping in the mud and he got stuck. He said the LSD didn't work. I told him that I believe in that situation you have to set the parking brake to get the LSD to engage. Is that correct for the 3rd gen American Axles? I know the 2nd gen has a Dana rear with clutch packs but I thought the AAM axle used a worm gear for the LSD.
(My 2nd gen. owners manual says that for trucks equipped with the LSD, when one wheel is slipping and one is on hard ground, that you should apply the parking brake and then throttle, it also says if both tires are slipping that all you have to do is hit the throttle to engage the LSD, didn't know if this was true for the AAM)
He was going to go home and try it. I hope it worked, he said he would turn the truck back in if it didn't (and go with a 4x4).

~Rob

 

I am curious on this too. I was in some mud just today testing mine out. Only one of my rears spun. I put the brakes on and gave it some gas, then they both spun and stayed together. I don't know if the beakes had anything to do with it or if the mud just got equally slippery.

 

Doesnt the owners manual explain how to work this.?

 

My 2nd gen. manual does. The guy I was talking to said he read his manual "from cover to cover" and doesn't remember seeing anything about the LSD. I think he just forgot. I bet it is towards the end and that is a lot of information to absorb in one reading.

~Rob

 

The owners manual on the 3rd gens does indicate you may have to partially set the parking brake to get the LSD to engage.

 

where in the book does it say anything about how to make the rear function properly?
I have tried every method and nothing works. I am also on my second differential.
Still never worked! I read my book and never saw what you saw. Can you tell us what page # you read that info on?

 

Setting the parking brake a little does help, I tried it today, but my question is WHY ? The parking brake is only on the drivers side tire, right ? So if the pass side tire is the only one spinning, how does the brake help ? Me lost, I understand lockers and clutched posi's, but this thing is just

 

First I'm new here and would like to say hi to all.
Second your e brake is hooked to both back wheels unless a cable broke, in
which case neither side will work. Applying the brake a couple of notches helps to equalize the torque to both sides.

 

Chapter 5 page 237.

 

Helical type (Torsen) differentials work on a bias ratio. If one has too little traction, it will be an open diff. You have to set the parking brake so the spinning wheel is "loaded" and both will spin.

 

thanks Buzzer, I found it in my book.
I can't belive what it says but you are right.

 

Is anyone getting a "chatter" on their LSD when turning left or right slowly. I was having this problem. A dealer told me that I needed TSB 03-003-04 drive line shutter ... I changed the diff oil- it was due and the shutter went away.

Comments

cheers frank

 

This is a good question. I have a 05 with the new rear. My paper work did not say if it is a posi or not. The sticker in the glove box only tells me it is a 11.50 rear. So I decided to find out. Dumping the clutch left 2 good long marks, but when I jacked it up and spun to wheels one turns the op way. if I turn the other, nothing would happen to the other. So I guessed I have a open rear. Right or Wrong?

 

The normal ways of determining whether it's limited slip or not don't apply to our type of differentials, because they don't use friction clutches. The answer to whether your truck has limited slip or not is in the glove box-literally. Open the glove box and look at the sticker inside the glove box door. If you have limited slip, it'll list it there.