One thing I forgot to add about the Powertrax. With my automatic transmission, the driveline lash when I let off and then get back on the throttle at cruising speeds is noticeable, but not a problem. With a manual transmission, it might be a challenge to shift smoothly with the Powertrax installed.

Before installing one in a truck with a manual transmission, it would be worth checking with someone who has done so to make sure it's tolerable...

 

Whats the diff between a limited slip and a locker

 

Limited slip engauges itself when it detects one wheel spinning significantly fast than the other. it then transferes power to the stationary wheel.

A locker will keep both wheels spinning exactly the same all the time, when it is engauged.

LS is always "on" but acts like an open diff in daily driving.
A locker can be turned "on" and off, when in the off setting it acts as an open diff, but in the on setting it creates the senario stated above.

Idiomaticman

 

By rebuilding the trac lock and add an extra disk and steel on each side.

 

That's not how a LS works. The LS drives both wheels equally until the load difference between the two wheels exceeds the friction in the clutch packs. At that point the clutches slip and the wheels can operate at different speeds. The wheel with the least load always gets the majority of the torque. The unladen wheel gets whatever the slipping clutches can transmit, usually about 25-30% when they are new, less as they age. On snow and ice there is not enough traction to cause the clutches to slip and the LS acts like a locker.

 

Idio and StrangeRanger,
I don't like eithier of ya'lls definition.


Here's the Limited Slip definition from Randy's Ring & Pinion:

" Transmits equal torque to both wheels when driving straight ahead. However when one wheel spins due to loss of traction, a patch of ice, mud, too much throttle, etc., the unit automatically provides more torque to the wheel that has traction. Recommended for daily driving, works well in ice, rain, mud and snow. However, in situations where absolute lockup is needed, a limited slip is not the best choice due to the fact that limited slips do slip in some situations.

Positraction is a type of limited slip and is a term that is used very loosely as another name or description for limited slip differentials. A positraction is not more aggressive than a limited slip or vice versa. The name "positraction" was used by General Motors for their limited slip differential and the name has been associated with limited slips for many years. "

According to Reider Racing, The Dana Trac-Lok provids 50% more traction over open diffs and Dana Power-Lok provides 75% more than open diffs.

Ford Racing is the Traction Lok found in Ford rear ends and It is probably comparable to the Dana units.

Precicion Gear manufactures a version of Dana's Trac-Lok and Power-Lok and are similar.

Here is Reiders info page on various lockers and limited Slip (positraction, trac-lok etc.): http://www.reiderracing.com/danatraclok.htm

Many but not all are described there. Also, there are some pretty good LS out there that have gears such as the Detroit True Trac

 

I don't care what they say, what I described is how it works. The clutches are between the spiders and the carrier and limit the amount that the axles can slip (i.e. differentiate) hence the term.

A Detroit Tru-Trac is not a limited slip. It is a torque sensing didfferential. It sends the majority of thr torque to the laden wheel up to the limit set by the bias ratio. There are no clutches therefore there is no slip.

 

So you know more than Randy at Randy's ring and pinion . . . ooo.k.

Trachtech the maker and disigner of the Detroit True Trac says its a limited slip. Go here and scroll down to the bottom where Trachtechs limited slips are and download the pdf brochure: http://www.tractech.com/Products.htm#true

TrachTehc calls their LSD torque sensitive and their lockers speed sensitive.

 

I'm not trying to start a fight, but the whole point of the TrueTrac and the other torque-sensing diffs like the Quaiffe and the Torsen is that they are not limited slips, they are worlds better than any limited slip. First of all there are no clutches to wear out and secondly, but more importantly, they transmit the majority of the torque to the wheel that has the majority of the load.

Limited slips transmit most of the torque to the unladen wheel and only a portion, determined by the pre-load in the clutch packs, is transmitted to the driving wheel. That is the reason that people re-shim stock limited slips, to increase the pre-load and thus the amount of torque which the slipping clutch pack transmits to the driving wheel.

The next time you're inside a limited slip differential, look at what the bits and pieces are, how they go together and how they work. It's not at all complicated.

 

This isn't a fight, its a debate! I didn't say the Detroit True Trac had clutches, it has gears. Trachtech clearly markets it as a ls. and lists it as lsd. I have one front and rear in a 97 F250 HD. I agree that it works more like a soft locker, especially if you lightly touch the brake to "trick" it. The next thing up in agressiveness from Trachtech would be the Soft Locker, but they are a bit pricey comparatively speaking.

Dana's Power Lok isn't a bad unit and is more aggressive than their Track Loc but is available for limited number of applications and is relatively expensive.

I'm not familiar with Torsen stuff, but Auburn and Eaton limited slips have to be rebuilt after some point. That is why in a 4x4, Detroit True Trac is the best ls option.

Advantages of LS units in reverse order IMHO:

3. The Eaton ls and Auburn ls (I think) requires factory rebuild.

2. Track Lok and Power Lok can be rebuilt by the individual.

1. Detroit True Trac has gears in lieu of clutches and doesn't need rebuilt.

I don't know much about the Torsen(and even less about the Quaife) other than availablity was limited in the past but that has apparently changed in the past couple of years.

I have an Eaton Elocker in the 8.8 of my Bronco and an EZ locker up front. I will be switchinc the ez locker out with a Dana Track Lok in the future because I thing the ez is too much up there with the stock axles. The reason I'll use the Track Lok is because I have one laying around. I haven't decide whether I'll put an extra clutch in each side when I rebuild it or not.

Again, this isn't a fight, its a debate. The thread starter seems to have dissappeared anyway!

 

No, I haven't disappeared. I've been reading your debate, but I don't have much to add due to lack of experience with any of these. As I said earlier
I appreciate all the information and am leaning towards the powertrax no slip for the rear as it sounds like what I'm looking for and could probably do myself. So, with that said hijack away!

 

The Torsen, Quaiffe and TrueTrac all operate on the same principle, just different fittments for different differentials. I'm guessing that Tractech markets the TrueTrac as a LS to distinguish it from a locker and to avoid having to explain the inner workings of the diff which are actually quite complex. I remember reading Gleason's original article announcing the design in the engineering journals 25-30 years ago. The math surrounding helix angles, bias ratios, etc. got fairly deep. The fact remains that nothing slips in a Tractech and there's nothing which limits the non-existant slip, so it is not a limited slip.

 

I wonder if they sell one for the 10.25 sterling? I need to do something as well...

 

Hey Desert Rider,

I have a 10.25 as well. Did you install the Lockright? If so, how did it turn out?

I have a 4x2 250 and I need something in the rear until I can convert to 4x4 if ever. I was thinking ARB or some other user activated Locker. I don't live near snow now but I may soon. I don't want any handling problems..

Thanks...

 

I've had a while to test drive the Powertrax No-Slip I put in my rear diff.

It is quiet and smooth in a straight line, and seems to be working fine. However, there are a couple of situations that it doesn't shine in. Making a hard right turn into traffic, say from a stop sign or right-turn-on-red situation, by design it gives the power to the passenger-side (inside) wheel. On a dry road, get a little too heavy on the throttle and you'll do a pretty impressive burnout with that wheel. By "too heavy" I mean no more than you ordinarily would use to scoot into a break in traffic. On a rain-slick road, you just sit and spin. It isn't as noticeable on left-hand turns, mainly because the turn isn't as sharp, I guess.

I would say this effect is a little worse than the stock open diff on wet roads, and much more noticeable than the stock diff on dry.

In normal right- and left-hand turns, not from a standing start, that is, it doesn't cause any problems.

Overall, I am happy with the Powertrax No-Slip, and I haven't gotten stuck yet, but this does take away some of my enthusiasm about this diff as an option.