Why a suregrip?

[RustyRatRod]

i hear ya mbaird, but a "posi" unit is 2 wheels pulling. a "limited slip" is one wheel pulling..........i still don't get it.

Nope. The term limited slip applies to every single carrier with clutches, cones, or gears like a True Track. Limited slip is an umbrella term. Sure Grip, Posi, Anti Spin, Track Lock, Traction Lock and so on are all manufacturer's brand names for the different makes of limited slips. A limited slip pulls with both wheels and allows a limited amount of slip between two axles as the name implies to take a turn.

Yet another thread back from the dead. lol

 

[66fyssh]

 

[1plydust]

Having had several sure grips over the years, it acts as a peg leg under normal driving, then when ya gas on it pretty good the clutches grip or lock in under hard type accelerations and cause both wheels take hold or grip, giving better hole shots one could say, but (don't try it in turning corners), also if you hear a click or slight popping from one, there is a rear end additive for sure grip and limited slip rear ends that helps, it worked for mine...

 

[vntned]

Hmmmmm, semantics…

Engine vs Motor

According to dictionary.com a motor is defined as: a machine, especially one powered by electricity or internal combustion, that supplies motivepower for a vehicle or for some other device with moving parts. While an engine is defined as: a machine for converting thermal energy into mechanical energy or power to produce force and motion.

 

[69hemibeep]

MANUFACTURER	MONIKER
American Motors	Twin Grip
Buick	Positive Traction
Cadillac	Anti Spin
Chevrolet	Positraction
Ford Motor Co.	Traction-Lok
Mopar	Sure Grip
Oldsmobile	Anti Spin
Pontiac	Saf-T-Track

 

[toolmanmike]

With any kind of power under the hood a "one wheel peel" isn't a good thing when it comes to traction. Sure Grip to the rescue. (or Power Lok if you have a Dana)

 

[MidnightSwinger]

My limited slip differential identifies as a Sure Grip.

 

[AJ/FormS]

BTW
1) the CONE-type Mopar LSD, the one that has two large spiders, can be adjusted from full-open action to almost spool type action, by some combination of cone-preload, oil type, and amount of friction-modifier.
2) the other type of Mopar LSD, the one that has clutches and four smaller spiders, can also be adjusted, but it's torque-sensing system has a broader smoother range.
At low torque-input it acts like an open diff. At max torque input, it acts like a spool. By varying the torque-input, you can vary the holding force.
For my driving style, this has a special meaning.
I like to drift as often as possible.I have set my car up to make this a relatively safe operation. When I put the power into it, she locks up and a-drifting we will go. If I feel that the drift is not going all that well, I just lift until the clutches relax, and the tires grab, then hit it again. While the tires are catching, the car may do a little lurch, which, when it happens, scares the crap out of passengers, so I don't take passengers with me anymore.
But I gotta tell you, this only works with tires that have lots of width, cuz the brakes don't work when the car is going sideways, and I depend on the now-floating contact patch to accomplish braking Before I installed 295s, not spinning-out was always a challenge. With the 295s, first and second gear drifting are almost too simple; turn steering-wheel, apply gas-pedal until tires spin, control speed and direction with gas-pedal, applying occasional counter-steer as may be necessary. Note-to-self, try to have the front tires pointing in the direction of travel when relaxing the gas-pedal, for minimum lurch.

 

[SpeedThrills]

Geez, get a spool!

 

[Jadaharabi]

Chrysler, was using the Trac loc (2 pinion gears) back in the 70s clear up until the present in pickups and Jeeps. In both the 8 1/4, the 9 inch and the Dana 60 the 70. Same unit Ford used in their Dana's.
Although it's not as strong as the Power Loc(4 pinions) that was used in the 8 3/4, the Dana 60, 70 and 80 used by Chevy and Ford also.

 

[Kern Dog]

Man....there are a LOT of ignorant people in this hobby.

i hear ya mbaird, but a "posi" unit is 2 wheels pulling. a "limited slip" is one wheel pulling..........i still don't get it.

Uhh, No...not even close. As stated before, the word POSI is short for "Posi-traction". This is a brand name from Chevrolet to describe their limited slip differential that served to equalize traction between the left and right wheels. Once the unit wears or breaks, the drive shaft then only transmits power to one wheel.

Not to be the over corrective a$$hole but Fords term of choice is Limited Slip

And limited slip is both wheels applying power to the pavement... if its a one legger its just a plain old "open" diff

Again, the term "Limited Slip" applies to all differentials that have some manner of function to equalize traction for both rear wheels. Nobody had ownership of this term.

i hear ya 71Duster. i didn't realise ford used that term for theirs. gm used the "limited slip" term for their open rears, and "posi" for their two legged rears....

More ignorance from this guy. NO open differential was correctly called a "limited slip" by any manufacturer.

i don't know if they still do either. so why does everyone always ask if you have a "suregrip"? just why is the "suregrip" rear so good? it is a open rear from what i know of it. why wouldn't everyone want to just put a "posi" unit in it? i know with GM this is the first thing most everybody does......am i crazy or is this just me not understanding?

Every manufacturer that I know of offered some type of differential that served to equalize traction for both rear tires. Most of them did have specific brand names for their differential.

An open differential drives both wheels, but if one of the wheels looses traction then ALL the torque is directed to that one wheel that is spinning. This is what the majority of cars have. These are often refered to as a 'peg leg' rear end.

A limited slip differential is one that 'limits' the amount of torque applied to only one wheel. There are several implementations that accomplish this. One is to use spring loaded clutch discs, a typical example is the Eaton differential. Another way is to use cones instead of the clutches, the example for this is the Auburn differential. Mopar's marketing name for limited slip is 'Suregrip'. And all Suregrips fall into one of these two types of limited slip. Often times these limited slip differentials are called a 'posi', but that is incorrect

Next is the locking differential. This does not use traditional clutches, it use 'cogs' to positively lock the two axles yet still allows one axle to spin faster than the other in turns. This differential is correctly refered to as a 'posi' and the example of this is the Detroit Locker.

In full blown race cars a spool replaces the differential. This solidly locks the two axles together and does not allow either side to spin faster than the opposite side.

There is also a torque biasing differential that behaves similar to a limited slip. These are more common on FWD transaxles.

And there is also an aftermarket device called a Powertrax that can be added to an open differential to make it work similar to a limited slip. The sad thing is they cost as much or more than a true limited slip. However you don't have to disturb the gears to install it so it's easy for the backyard mechanic to set up.

^^^ Finally, someone with brains chimes in to set the others straight. Thank you!

I have always called them all Posi"s all my life and I have always been a Mopar man. We all know what the heck we mean anyway ! Ron

Ron, you're a nice guy but technically, you're using wrong terminology. Do Chevy guys call their 454 a Hemi? POSI is not a Mopar term.

MANUFACTURER	MONIKER
American Motors	Twin Grip
Buick	Positive Traction
Cadillac	Anti Spin
Chevrolet	Positraction
Ford Motor Co.	Traction-Lok
Mopar	Sure Grip
Oldsmobile	Anti Spin
Pontiac	Saf-T-Track

Here is an excellent post. It outlines the specific brand names of what is essentially the same functioning device in different cars.
Yes, we usually know what people mean when they say their car has a POSI even if it is a Duster. For a lot of us, we get tired of GM and Chevrolet getting so much fanfare and attention in this hobby. Personally, I try hard to avoid using Chevrolet terms. I never hear people refer to their 833 transmissions as a Rock Crusher 833. Nobody calls their automatic a Turbo 727. Does anyone ever ask a Corvette guy if their car has a 427 six pack?

 

[MoparLeo]

This discussion sounds almost like trying to explain something to a Democrat...