Locker VS Posi

[BlueTahoe2001]

Ok, I have heard a lot of information about both lockers and posi units for the rear of our trucks.

I have some questions concerning both. For a locker- I know it's more off-road but I love the way my Fathers 78' Camaro drives with a locker. That thing doesn't miss a lick and seems like it still rides really well on the road despite the fact it is a locker. Doesn't have a ton of wheel hop but does have some.

For a Posi unit- What's the difference between this and a locker? I am assuming that a Posi locks when needed and is unlocked when it's not? I have also heard you don't get the wheel hop you do of a locker?

Let's hear some opinions on this. Not sure which to go with yet but almost leaning toward a locker because of the Price over a Posi unit. Something like a Power-Trax because I can get them for $259.00.

 

[rob71]

Posi is a trade name for a limited slip differential; the automakers all have had different names over the years for limited slip - Posi-traction, Sure-Grip, etc...

A limited slip differential has the same internal gears as a normal open differential but also has friction clutches that can transfer power to both wheels when one wheel loses traction. The clutches are set up to slip a certain amount to allow normal differential action - that's where the left and right wheels have to turn at different speeds when you're turning a corner or going around a curve. The down side is that in extreme conditions (climbing up over slick rocks, or off roading where you lift a rear wheel of the ground - neither of which are likely situations for a Tahoe or Yukon) the clutches may not transfer enough torque to actually get the vehicle moving.

Lockers are more aggressive and have a locking mechanism like a ratchet between the left and right sides. They're great in severe offroad conditions like rock crawling, but if you drive in winter weather (ice, snow, even sometimes just rain) they can make the vehicle handle really unpredictably.

I've had vehicles with both types and I wouldn't have a locker on a street driven vehicle again unless it was really smooth acting. The abrupt ratcheting action of the aftermarket locker that was in the 14 bolt rear on my truck was unpleasant on the curved street I used to live on, and the rear end would kick out in turns in the wet weather. I used to live on a circle and I'd have to let off the gas about five times to let it unlock and get around the circle.

I don't like lockers on street driven vehicles - they're great for offroad though. That's just my opinion, take it for what it's worth. Today I was driving in about four to six inches of snow on the roads and I need predictable cornering, so a locker is out.

I have had limited slip differentials that were so tight they'd chatter in slow turns and people thought I had a locker ('89 Caprice police car for one), but it was just that the friction modifiers in the gear oil were all used up. I had a Porsche that would burn up the friction modifiers in about 2,000 miles and the diff would start groaning in slow turns until I changed the transaxle oil again.

The stock Gov-lock on these trucks is a bastard hybrid that should never have been sold - the limited slip clutch action is too weak, the case is too weak, and the locking mechanism is too weak. I'm looking forward to replacing mine with a normal clutch or cone style limited slip in the spring. You can pick up a good limited slip differential for around $400 these days, and that's not bad for what you get.

That's all my opinion, but it's up to you what you choose - it depends what you want to get out it.

 

[Sasquatch]

I just wanted to add that lockers have nothing to do with wheel hop.

this link explains what causes it. http://www.competitionengineering.com/articles/chassis2.asp

 

[pmbiker]

The link above is addressing wheel hop caused by straight line acceleration. The wheel hop were talking about is when the inside wheel hops going around a corner with a locker. That is due to the inside wheel going a shorter distance around the corner thus causing a bind.

 

[Sasquatch]

oh, ok. i`ve only known one version of wheel hop and thats the one in the link. thanks for clearing that up.

 

[Max]

I prefer the detroit tru trac helical limited slips in these 10 bolts, much smoother transition and less stress on parts.

 

[MOBmentality]

i agree with rob.. definitely would rather just run posi on the street.. but if i was that set on having the rear end lock..
i would honestly rather just deal with the wear and tear of a spool than i would the unpredictability of lockers. at least then you KNOW its gonna chirp on tight corners and stuff.. and not have to toss a coin each time

 

[rucr8z2]

Everyday driving get a posi unit or a electric locker(turn on when you need it)
Don't get the powertrax its just a replacement for the spider gears and its clicking got on my nerves badly!!!!!!!!!!!!! ( but easy to install though)

 

[BOSS]

Great information, keep it coming - gunna stick this one

B

 

[rucr8z2]

I prefer the detroit tru trac helical limited slips in these 10 bolts, much smoother transition and less stress on parts.

The Tru Trac is the Factory limited slip on Dodge trucks.

 

[BlueTahoe2001]

It's been a while since I was able to get around to this thread. Thanks guys for all the great information.

Now, Considering my options what would be better in this case. POSI VS. Electric locker?

Assuming that I have to drive the Tahoe around the Farm every now and then and also pull a weighted trailer with the Tahoe sometimes as well. Trailer weighs a good bit with all the Dirt and what not in it.

I was thinking that an electric locker could come in more handy allowing me to have that extra traction on demand and have it open on the street?

 

[kickitandholdit]

look up powertrax they at richmong gears the have videos showing the difference. i got a powertrax no slip its pricy but amazing

 

[WoldD90]

If you need a locker, get an e-locker or an ARB air locker. These are both selectable, allowing you to turn them on when you need them and only when you need them.

The traditional lockers are typically a Detroit or a TruTrack. These both activate with wheel spin, and they do not typically belong on a street only truck. They have been used in race and drag cars to keep traction.

 

[vwbeaner]

Here is some more info.
http://www.tahoeyukonforum.com/forum/showthread.php?t=11030

 

[ktmhans]

little bit of an old post here but I installed an Auburn gear type posi unit. maybe it was cones? I know there was nothing to wear out inthere. I had it in my 98 Tahoe. The harder you throttled it the harder it locked. but if you mashed the throttle in a corner it wouldn't break loose. Mash the throttle going straight and then turn. It would go right around locked up. I loved it!

On night in on dry pavement in front of my inlaws I got em spinning and did 5 full donuts with my tahoe. pretty cool.

 

[Bossy70]

I have street experience with a stock open rear, a spool, stock limited slip, a cone-clutch limited slip (Auburn), a Powertrax No-Slip locker (Richmond), and a Detroit TrueTrac (Eaton).

Like Max, I would suggest the Detoit TrueTrac. I actually have put this in two different vehicles, one being a 700rwhp street car. Operation is smooth and quiet, traction is great, and it seems to withstand a good bit of abuse. Also, they are maintanance free (no cluthes to replace like conventional "limited slip"/"posi").

 

[Max]

I have a trutrac and 4.56s in my denali and love it. Really depends on the application but I'm a huge fan of the trutrac for a limited slip, my shit hooks and engages smooth as butter. Oh and no factory vehicle that I know of comes with a trutrac, the dodges and most chrysler vehicles came with a trac lock which is a conventional clutch type lsd.

 

[2000Tahoe]

I off road and street drive and my Yota doesnt have any problems with a Locker I think what your looking for is a more positive locking diff spools are ok but your gonna wear out one rear tire because the rear end doesnt unlock when turning a corner a good locker will act like an open rear end when turning corners and will lock up again when driving in a straight line i have no issues with my locker driving on the street as i dont trailer my 4x4's i drive them 2 and from the trails and yes i do extreme with my one rig. anyway i really dont think your gonna wanna spool in that rear end street driving is not something you want a spool for your rear end will always be locked no matter what and you rear tire's will wear out because of that at least with a locker your rear end will act as normal iif it's installed right just my 2 cent's though from experience.

 

[ccapehartusarmyINF.(ret)]

4.56s diffs good lord the gas you must burn

 

[BeenChevy]

rob71 nailed it exactly with the G80-type. If you drive on slick road conditions more than loose gravel inclines the locker is less than ideal. It could be described by compare driving on ice with knobby mud tires vs. bizzak ice tires if that helps draw a picture.

Interested in swapping out with a 4.10 re-gear. Anyone recommend best bang for buck?