Positive Traction

[Smoke_Dog]

What are the Pros and Cons? I know what I want to do, but just need to understand why?

[Dalaigh]

I don't see any negatives to positive traction. With a posi or limited slip you get power going to both wheels when you need it, but during turns it still allows the wheels to move at slightly different speeds. If you get into a situation where one wheel slips the other will get power to get you out. You might lose some fuel economy (might being the operative word here) but thats the only con I can see. There are different types of Posi units you can get, but I've found that the best bang for buck is an Auburn limited slip.

[68Timber]

Why auburn over eaton? Just curious. To the op, the only downside I know of is purchase price and installation cost. While the rear end is torn apart its a good time to change the ring and pinion if you're thinking of a different rear gear ratio.

[Dalaigh]

Originally Posted by BRUISER

Why auburn over eaton? Just curious. To the op, the only downside I know of is purchase price and installation cost. While the rear end is torn apart its a good time to change the ring and pinion if you're thinking of a different rear gear ratio.

I've had good luck with Auburn, plus price wise the Auburn is cheaper. And if Eaton really wanted to make money, they'd talk GM into the True Track rather then the Gov bomb they supply know.

[wilkin250r]

There is another drawback that hasn't been mentioned yet. If you're in an area that you're likely to lose traction, like snow and ice conditions, a posi trac is more likely to spin out on you. If you give it too much gas, an open differential will break traction on only one tire, the other will still grip and often keep you from sliding out. A posi or a locker will spin and break traction on both tires, causing the rear end to slide out.

[INSIDIOUS '86]

Originally Posted by wilkin250r

There is another drawback that hasn't been mentioned yet. If you're in an area that you're likely to lose traction, like snow and ice conditions, a posi trac is more likely to spin out on you. If you give it too much gas, an open differential will break traction on only one tire, the other will still grip and often keep you from sliding out. A posi or a locker will spin and break traction on both tires, causing the rear end to slide out.

When a open diff unloads the wheel with no power(left turns) the spin out an loss is more sudden an even more dangerous.
Ie going sideways from a stop= low momentum an better time to react to the situation vs a open diff were it spins out during cornering at high momentum and you get surprised with very little time to react
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[bilfman]

There are many things to consider when choosing to modify your differential. I'll explain the basics on then and give some pros and cons. Ultimately it should be based on vehicle usage to make your decision.

Firstly differential basics, the 2 main reasons for a differential is 1. to get power to the tires and 2 to ease drivetrain stress when cornering(lets inside and outside tires turn at different speeds.

Readers digest versions below...

1. open diff- only 1 tire recieves power at any given time pros-cheap, safe due to never breaking both tires loose. cons- only one wheel traction
2. Limited slip/posi trac- these use clutches to apply traction to both tires. pros- does enable 2 tires to have power, enables slippage when cornering, cluth packs allow differential to minimize stress when cornering. cons-clutch packs can burn out under heavy srtess, it does not allow a full 100% delivery to both tires, in high load situations (such as deep mud or side of hill) it will let the tire with the least amount of resistance spin, not both. Usually this is the tire that won't get you moving. ie if you are off road and have a wheel in the air, that is the one that will be spinning, so you are stuck Can be dangerous for losing control on slippery road conditions.
3. Locker. There are several types of lockers out there. But basically it is a true lock that lets both tires get 100% traction. Their design does still allow for slippage on a turn, you may hear a ratcheting sound from your diff when cornering, it is a normal part of their design. pros- excellent 2 wheel traction even if a wheel is in the air your other tire will turn, No clutches to wear out. cons- can hear some of them, not the best choice for a front differential (eaton Tru-Trac works in the front well though), can loose control on slippery roads, must learn to alter your driving habits on ice and snow.
4 Spool- is a full mechanical lock of the rear diff, allows for no side to side slippage at any time. Pros- 100% traction all the time, strong (really no parts to wear) cons- tires will always chip or stutter on a corner, never use in the front of a recreational 4x4.

That is a basic rundown. I know that there is tons of more info to go to each, but I put what I did to be quick and to give Smoke_Dog a starting point for research.

My personal preference is a locker, I have used them for 20+ years and love the improvement they offer.I have owned high hp muscle cars and extreme 4x4's and am happy with the units. I personally think a rear locker is the single best improvement for a 4x4, hands down. I live in Canada in a harsh winter area and love the additional traction, but there is a big BUT here for sure. These can be extremely dangerous on ice, you really have to know your vehicle and watch how you throttle. A little too much on the highway at 60 and it can be the tilt o' whirl ride. I currently run a tru-trac in my front dana 60 and a detroit locker in the dana 70 rear. Works great and would never look back.

So if you are a 2wd pavement runner who wants to smoke 2 tires from time to time a limited slip is fine. If you to off road with your truck a bit, you can't beat a good locker.

Best of luck on your research!

[Pop's C-10]

Go with a powertrax..no gear set up & you can do it yaself

[406 Q-ship]

Originally Posted by Dalaigh

I've had good luck with Auburn, plus price wise the Auburn is cheaper. And if Eaton really wanted to make money, they'd talk GM into the True Track rather then the Gov bomb they supply know.

There is a reason the Auburns are cheaper, it is a cone style posi and are not rebuildable. When the cone (auburn) is worn it becomes an open differential. The Eaton is a plate style and can be easily rebuilt (even in the housing) they don't have the failure rate the cones do. I worked at a dealer and can tell you the GovLoc only fails when the driver get stupid with them and very few of them fail in normal use. A GovLoc fails when the driver gets the differential in the open and the tire starts to spin, then the driver hammers the throttle cause a HUGE wheel speed difference between the two rear tires.....It is like dropping the clutch on a completely stopped car with the engine at 8500, guess what something will explode. If the owners of GovLocs would actually read the owners manual they will see that your not supposed accelerate the slipping wheel beyond 20 MPH so the differential will conteck without the destruction.

I will agree that the TruTrac is a better design, I got one in my Chevelle that spends alots of time on road courses and I will never put anything else but a Tru Trac in a car that has to corner. I bet it would work great in a truck too, less likely to spin out like a locker or a friction style posi will.

[Smoke_Dog]

With all this being said! Let's make it simple! I'm just going to drive the truck normal and just like the fact that I have it, if needed! So what should i do?

[grs]

Originally Posted by wilkin250r

There is another drawback that hasn't been mentioned yet. If you're in an area that you're likely to lose traction, like snow and ice conditions, a posi trac is more likely to spin out on you. If you give it too much gas, an open differential will break traction on only one tire, the other will still grip and often keep you from sliding out. A posi or a locker will spin and break traction on both tires, causing the rear end to slide out.

I agree. I had a 1966 Plymouth Fury about 44 years ago. I gave it too much gas going around a corner and it spun around in a circle and wound up in a mans yard. There was snow on the street.

[Desert1957]

I personally need more info on what kind of driving you do?

*Do you tow?
*Do you have 4WD?
*Do you like to do "Burnouts"
*Is your current rear having issues or noises?
*Can you afford a complete differential overhaul?

This stuff gets pricey real quick, If your a daily driver, all road diving, I would say price up the swap Before you start tearing into the rear.

You may fing you may Not need it after all.

Desert

PS: Hey "Bilfman" Great explanation of all options on rears.

[Smoke_Dog]

Just want it just in case I need it!!! The truck is just a driver and it looks good!!!!

Originally Posted by Desert1957

I personally need more info on what kind of driving you do?

*Do you tow?
*Do you have 4WD?
*Do you like to do "Burnouts"
*Is your current rear having issues or noises?
*Can you afford a complete differential overhaul?

This stuff gets price real quick, If you a daily driver, all road diving, I would say price up the swap Before you start tearing into the rear.

You may fing you may Not need it after all.

Desert

PS: Hey "Bilfman" Great explanation of all options on rears.

[Smoke_Dog]

Going withe eaton!!! Will let U know How it went next week!!!

[Smoke_Dog]

Done ddeal went with 373's install complete Saturday

[INSIDIOUS '86]

Send smoke!
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[noco-k5]

Originally Posted by Smoke_Dog

Done ddeal went with 373's install complete Saturday

So how are the 3.73's? That's the swap I'm planning on doing in my Blazer from the current 3.07's.

[Smoke_Dog]

Feels a little different, but it hasn't been tested yet, because vaccum lines for engine, upgrades are not set up right! Bottom line is can't remember how things go!

Originally Posted by noco-k5

So how are the 3.73's? That's the swap I'm planning on doing in my Blazer from the current 3.07's.

[spencer_41188]

michanical lockers are not the way to go with a short wheel base. they will tend to lock and unlock when turning. when they lock on a corner you dont just hear it for feel it.

my truck dont turn well at all because its long i dont hear my locker inless the wheel it turned all the way like pulling into a parking spot. added bonis sounds like a pos and adds to the sleeper look lol

if you wont limit slip this is the way to go http://www.off-roadweb.com/tech/1101.../photo_07.html ... there are no clutches so you dont have to add anything to the oil and you can use your brakes to control the power to both wheels

i put a full spool in the front and a locker in the rear of my truck. i did this because i go mudding and do some truck pulling and its a daily driver, you wont wheel spin but not just 2 wheels. indiana has some bad winters and when i need to i lock 1 lockout and when i really need it ill lock both but not for long full spool in front is not verry streetable thats why i have lockouts insted of drive pucks

[INSIDIOUS '86]

I do a lot of road course in my truck. So I got a truetrac diff in mine with 373s and a 90's 30 spline axles and thick aluminum cover/stud girdle. I don't notice any difference in the way it drives other than it doesn't spin my right wheel all the time. I love the hell out of it. Well see how long it lasts. I'm good at exploiting the weak points in equipment
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[motornut]

my 79 has the "1G80" @3.4 ratio stock
but my 305 don't squeal em tires all the time lol
but sure throws the dirt and it does doughnuts on snow/ice
but i havn't been stuck yet

[gchemist]

Would you rather leave a single long streak? Or two long streaks and launch sideways with enough power?