[Helltime]

Where can I find a posi to put in my truck. Any good sites or tips.

 

[Dodgerjack]

Probably the most economical way: go to the boneyard and get the whole rear axle assembly. You can compare prices for new parts on line at Truckperformance.com or Makeitmopar.com, and others.

I replaced the axle assembly on my Camaro in '02 with one from a salvage yard that had a limited slip differential. Cost: $125. I think I got screwed on the installation at $250, but they swapped the brakes from my old one and did some other stuff. Labor is always a big consideration when you price these things out.

Prices vary at the salvage yards, but this will give you some idea, I hope. Of course, you're buying used, and that has its risks. Good yards always warranty the part, though. Be sure to ask, if you go that route.

Limited slips are verrry nice. I've hardly ever had a car or truck without one. It's almost ridiculous that anything gets shipped new with an open diff, considering that the option is usually about 50 bucks (at least it used to be). It's a no-brainer if you're looking for a new vehicle, especially if you're ordering one.

Hope you get yours soon! :biggthump

 

[Helltime]

A family friend of our owns a bone yard and if it is a $75 part I can get it for about $20 and if it is about a $15 part I can have it for free most likely. As for labor well even though I am only 14 me and my dad work on our own cars because to put it in the shop that is a lot of money I could put in to more performance parts. I love driving a posi because it makes it fun when you have to counter steer. I love the mustang we have because until I get my dad's dakota it is the only one that has a posi or limited slip.

 

[Dodgerjack]

Sounds like you should get to the yard. I hope you have a safe place to do all that motor-head driving! The real benefit of the limited slip on a truck is on slippery stuff and mud. Put it in 4-wheel drive and you notice a real difference with the locker. Plus, you can leave it in 2-wheel a lot of times and not even need the 4-wheel, especially if you have some extra weight in the back. Is your truck a 4x4?

 

[92dakotahd]

Not trying to be an A$$ but I got this pounded into me.

Posi Rear-ends are GM.


We're mopars, it's a Limited-Slip differential. :sorry:

 

[Dodgerjack]

Ya got that right about Posi-Traction being a GM brand, like Ford is Traction-Lok, but is Limited Slip a Chrysler trade name or a generic term? I guess maybe they don't have a tricky brand name like Super-Grabber or whatever...?

 

[MNBiker]

Ya got that right about Posi-Traction being a GM brand, like Ford is Traction-Lok, but is Limited Slip a Chrysler trade name or a generic term? I guess maybe they don't have a tricky brand name like Super-Grabber or whatever...?

In the good ol' muscle car days, the Mopar version of limited slip was called Sure Grip.

 

[Helltime]

Ok sorry about the posi thing. My family used to be in to GM key words being "USED TO BE". And yes it is 4X4.

 

[Dodgerjack]

Its all the same thing, its just a different name for a different design, they all operate under the EXACT same principle.

Whoa there, not quite. There are definitely differences between limited slip differential designs. The clutch type transfer torque to the wheel with traction through clutches, and are limited in how much they transfer by the resistance of the clutches.

The "locker" differential actually uses gears to transfer the torque, resulting in up to 100% of the torque being transferred to the wheel with traction. They are for "serious off-road use" and use an electrical engagement system.

There is also the "Detroit Locker" version, which is a gear type that doesn't require an engagement system and still allows the outside wheel to spin faster around corners. (I understand that these are noisy)

The "Torsen" (for TORque-SENsing) differential uses gears and is all-mechanical. A really neat set-up.

There are more types, including viscous couplings, but these are the main ones you'd run across for truck and muscle car applications.

As far as nomenclature is concerned, I'm pretty sure that "limited slip" is basically a generic term, and for sure "traction control" is. There really is kind of a basic difference between "limited slip" and "locking" types, in that the LS does not transfer all the torque, but only a limited amount. The viscous coupling and clutch types would be considered "limited slip" while the gear types would probably be more accurately described as "locking." The Torsen is really the best of both worlds, as it "senses" and transfers the amount of torque needed--up to 100%--based on the conditions.

Here's a place to read more about differentials and how they work:

http://auto.howstuffworks.com/differential8.htm

 

[Dodgerjack]

No offense intended, I just don't think you can say "they all operate under the exact same principle" without creating confusion. They all have a similar goal, which is varying degrees of traction control, but their operating principles are very different. Also, the "end result" which you mention in your last post differs depending on the type of unit, in that the torque transfer can range from "limited" (<100%) to "locking" (100%). I read you post carefully and thought it was important to make this distinction. You may have known full well what you meant, but others may not have.

Yes, the electrically/pneumatically/hydraulically operated units use an "on off" switch. This, again, is a very different operating principle than those that use clutches, self-locking gears or viscous couplings. The end result is similar to, but not exactly the same as, self-locking gears, because the true "locker" always transfers the torque equally to both wheels.

 

[T.j.]

All I know is I need one.....Could I just change out the entire rear end and put the 9.25 from an r/t in my truck, then just use the lsd that comes from the factory? I got quoted at 1700 for 4.56's front and rear, and an Auburn lsd installed in my 8.25, But If i can find a wrecked r/t Thatd prolly be alot cheaper right?

 

[dgc333]

You can purchase a Tru-Trac limited slip similar to what the factory used for under $200 new. You will need new carrier bearings since you can get the bearings off the existing diff without ruining them but the bearings are only $60ish for the set.

If you are not in a position to do this work your self it should not be more than 2-3 hours labor.

Best palce to have this work down is at a shop that specializes in 4x4's they will have a lot more experince thant the dealer and will charge a fair rate, not flat rate.

Another option is a Power Trax unit. It does not require that you remove the current diff and disturb the gear set-up. For a do it your selfer it only requires that you remove the rear cover and pull the axles. Then the side and spider gears are removed from the exisitng diff and the Power Trax is installed. This would be a 1-2 hour job. These units are more costly around $400.

 

[Helltime]

My dad has done all this stuff before so I'm sure we can handle it. Now I am not sure I will do anything to this truck because it is rusting out bad and If I am going to spend money on something I want it to look nice. I will just drive it for what it is and it is a tough truck that runs good and will get me where I need to go reliabley. I might get a newer dakota that is in good shape then play with that, But that is a few years away.

 

[GregZ]

You will need new carrier bearings since you can get the bearings off the existing diff without ruining them .

You actually can remove the bearings without damaging them, it just requires the proper tools.

 

[Dodgerjack]

...those are all limited slip diffs, when turning one side is being allowed to slip via various means, clutch packs, racheting gears, bevel/cone type etc. All these are your general OEM posi's. When turning they are allowed to slip when poor traction results they lock up, very simple, these are the "operating principles" I was refering to.

That makes it much more clear. In very general terms, you might say that the goal of limited slip differentials is the same--transferring torque to the wheel with traction when one wheel starts to slip, while still allowing the outside wheel to travel faster than the inside one around curves in normal driving. However, your statements that I quoted directly (I don't think they were misquoted) was that "they all operate under the EXACT same principle" and that the "end result was the same". I thought that needed clarification, because even if YOU know that there are vast differences between the way "limited slip" is achieved, as well as differences in the resulting performance, someone reading those statements COULD get the impression that there are no differences. I think "operating principle" usually refers to HOW something works, not the general definition of what it does, and I wanted to make it clear that limited slip differentials work different ways and give different results depending on their basic design (or what I would call their "operating principle.")

True, clutch packs, racheting gears, bevel/cone type etc. may all be offered as OEM equipment, and they are all made to differentiate under normal driving and give varying degrees of torque transfer under conditions of one-wheel slippage. There may also be different manufactuers' designs of clutch types, different designs of racheting gear types, and different designs of bevel/cone types, BUT the different types themselves--what I would say involves their "operating principles"--are definitely different and they perform differently.

The TorSen uses a unique operating principle, and should be included with OEM types, as production V8 Camaros came equipped with these differentials starting in 1998. Viscous couplings are also used in OEM applications and they are "limited slip."

Since this thread was about questions regarding putting a "posi" in a truck, I think it's good that some discussion of the wide range of options has been presented. Personally, if I was seriously into off-roading, I'd consider TorSens front and back, or what has been referred to as 4x4x4. (I don't know if that's possible on our trucks, though.) With this setup, if ONE wheel front or back has traction, it can probably pull you out. (This setup is "OEM" on the military Hummer--maybe available on civilian ones? Don't know much 'bout Hummers, couldn't afford one, or the gas.)

 

[dgc333]

You actually can remove the bearings without damaging them, it just requires the proper tools.

Well the rear end I rebuilt just recently and the few that I have looked at do not have reliefs machined in the carrier that will allow you to get a bearing puller behind the race to pull them off with out damaging them. I will stand corrected that if there has been provisions machined into the carrier to remove a bearing yes you can get them off.

But, if you are installing a new diff why would you want to reuse bearings?