LSD Differential

So what makes the auto lsd different from the trac system? Both use brakes to control wheel spin and gain traction, in the manual it seems that the difference is that the trac will work while in 4x4 and the auto lsd doesn't.

 

one of them will cut power to the wheel, the other one will only brake but not cut power, IIRC

it's in the manual but you have to like read it 20 times to understand it hehe

 

so which cuts the power, the trac? I finally got my 09 in the mud 2 weeks ago and something (must have been trac cause I had it in 4hi) kept turning on and beeping. I could really feel it. I would start to slip and BEEP, the truck woud jerk around a little bit. Seemed like it worked pretty well.

 

The TRAC cut's the power. But if I remember correctly the VSC is what sounds an audible alarm when it is in use.
You can turn the VSC off with one quick push of the "VSC off button", holding the button for three sec turns off VSC and TRAC.

 

But I was quoting your statement above top and you have an 09.

Thinking about it now your quote above top is in reference to the OP and not your truck.

My bad.

 

o.k. - same church, different pew. I'm getting ready to change the oil in both of the diff's with Amsoil and have purchased the LSD additive for the rear one which now I'm not sure whether I need. 09 Sport 4x4 so it has auto LSD right? The rear diff doesn't have an LSD sticker on it as I've seen a picture of on some of the other threads. So sounds like the additive may not be needed but should be o.k. to put in anyway so I won't be taking the chance of the grinding. Also, does anyone remember the size of the wrench/socket for the rear diff? 24mm maybe?

 

You do not need the friction modifier for the rear end. Save your self the couple bucks and return it. You also do not have a LSD in the rear. You have what is called the Auto-LSD system that uses the brakes to mitigate power between the rear wheels. So your differential is the exact same as an open differential, thus not needing any sort of additive.

Yes, you will need a 24mm socket for the drain plug. Use a 6 point as to not damage the bolt.

 

Thanks, I thought so - just confirming. Can you give me a brief splainin' of "open differential" - I assume that it's essentially just a plain go around the corner diff, no bells or whistles. Does the "auto" apply varying amounts of pressure to the spinning tire? can you add a locker to the rear and why? I do little towing, little off roading, use the 4x4 mostly for snow and gravel mountain roads.

 

It's ok but I wish I had a true lsd...

 

You're going in the right direction on how an open differential works. The best way to see for yourself how it actually works is to look up a diagram on the Internet.

Yes, the auto-LSD works by utilizing the rear brakes. They are each applied independently from each other to re-direct wheel spin to the opposing wheel and in turn, increasing traction.

An ARB locker will fit in your rear end, although, I do not know of anyone that has put one in a 2009 model yet. There could potentially be some serious issues if you had VSC come on when the locker was engaged. The reason you would use a locker vs. LSD is because a LSD still has slip, hence limited slip differential. A locker is 1:1 with absolutely no slip. This is beneficial for when you get a tire up in the air.