Locking Differential versus Limited Slip differential

[White Lightening]

Originally Posted by twomorestrokes

When I ran my VIN on GM VIS it came up as G80 / Locking Differential- Rear Axle.

My guess is that GM's version is just another name for limited slip, not a true locker.

My 2004 Silverado has a RPO code of G80.

Directly from the RPO Codes guide is the following:
"G80 Differential, locking, heavy-duty, rear
G86 Differential, limited slip, heavy-duty, rear"

[jethro_3]

Get the RPO Detail print out from the dealer to verify exactly what you have. Some codes were different to models in the same year.

Also you can get the mechanics in the dealers shop to tell you what the difference is, they have torn down a few I bet.

[twomorestrokes]

Originally Posted by Moose is loose

No clutches on a true "locker". They use metal teeth that mesh together--locked. The only way they can slip is when the teeth basically skip a cog (causing the BANG!). This should help:
http://www.powertrax.com/nsexploded.html

Right. These G80's must be basically just a limited slip simply named "locker" by GM. Correct?

[White Lightening]

Originally Posted by twomorestrokes

Right. These G80's must be basically just a limited slip simply named "locker" by GM. Correct?

From my understanding - the G86 is the limited slip version (not positration but limited slip) - while the G80 (positraction) is the type used in the SS and in my v.h.o. 2wd truck. My understanding (from others) is that positration is a better traction method than is limited slip - and is often used in heavier duty or higher powered vehicles).

[twomorestrokes]

Originally Posted by White Lightening

From my understanding - the G86 is the limited slip version (not positration but limited slip) - while the G80 (positraction) is the type used in the SS and in my v.h.o. 2wd truck. My understanding (from others) is that positration is a better traction method than is limited slip - and is often used in heavier duty or higher powered vehicles).

Positraction and Limited Slip are two names for the same thing. The G80 locker also uses clutches, but a flyweight and cam setup to operate the clutches. Check this link, complete with video.

http://www.traction.eaton.com/prod2.htm

[twomorestrokes]

Originally Posted by twomorestrokes

Positraction and Limited Slip are two names for the same thing. The G80 locker also uses clutches, but a flyweight and cam setup to operate the clutches. Check this link, complete with video.

http://www.traction.eaton.com/prod2.htm

I also did a search engine of "G80 locking differential" and found forums where complaints of the Eaton locker (G80) was chattering on turns when hot. The fix (according to GM, according to this forum) was to replace the diff fluid with synthetic, but DO NOT add the friction modifier additive to this G80 setup. If so, it should be flushed, as the discs are metal and the additive can cause them to glaze over.

Apparently GM's locker and limited slip are two different types of differentials.

[BlenderWizard]

I think if more people new of and understood the benefits of LSD's and locking diffs, there would be a lot fewer 4wd vehicles on the road.

[redneck45]

you got me thinkin now, my duramax G80 I put mobil 1 syn in and it acted fine as well as the G80 in my '99 1/2 ton, but my '97 formula firebird when I put just the mobil 1 in made a hellava racket until I put in a bottle of the "limited slip lube"! Def. two different types of rears!

[05SilvyHP]

The locking diff in the chevy rear on my truck is a limited slip posi. If it were a locker, like everyone has said, if would be way annoying when turning. The limited slip allows for just that--limited slip of each of the rear wheels. A locker or spool is terrible on turns, especially tight parking lot manuevers. It allows for no slip, which is great for drag racing or off-road traction, but sucks in everyday driving.

later

[Moose is loose]

I had a 1970 Chevy C-10 with a Posi rear. If I didn't use the GM addative, it sounded like I had timing gears at any speed above 40. Sounded kinda cool, but after having to replace the rear, it wasn't so cool. I was also 16 back then. Just be sure to use the $$$$ bottle of addative from GM, it will save ya.

[BlenderWizard]

Originally Posted by 05SilvyHP

The locking diff in the chevy rear on my truck is a limited slip posi. If it were a locker, like everyone has said, if would be way annoying when turning. The limited slip allows for just that--limited slip of each of the rear wheels. A locker or spool is terrible on turns, especially tight parking lot manuevers. It allows for no slip, which is great for drag racing or off-road traction, but sucks in everyday driving.

later

This is the LOCKER that's in the Chevy, like twomorestrokes said
http://www.traction.eaton.com/prod2.htm
Read the page, it is a locker; Eaton has a seperate pager for their posi/LSD setup.

[spudglo08]

For Clutch-Type Limited Slip
Go to http://auto.howstuffworks.com/differential8.htm
For Locking and Torsen® diffs
go to http://auto.howstuffworks.com/differential10.htm

[spudglo08]

GM doesnt use a "true" locker cus it only engages if the drive weel slips.To demonstrate find some dirt and do a burn out but slowly give it gas and listen after about 1-2 revolutions of the drive tire "left weel" you will here a ping sond and the right tire will start to spin if you have a locker if not the left will just keep spinning.

[spudglo08]

The Torsen differential* is a purely mechanical device; it has no electronics, clutches or viscous fluids

The Torsen (from Torque Sensing) works as an open differential when the amount of torque going to each wheel is equal. As soon as one wheel starts to lose traction, the difference in torque causes the gears in the Torsen differential to bind together. The design of the gears in the differential determines the torque bias ratio. For instance, if a particular Torsen differential is designed with a 5:1 bias ratio, it is capable of applying up to five times more torque to the wheel that has good traction.

These devices are often used in high-performance all-wheel-drive vehicles. Like the viscous coupling, they are often used to transfer power between the front and rear wheels. In this application, the Torsen is superior to the viscous coupling because it transfers torque to the stable wheels before the actual slipping occurs.

However, if one set of wheels loses traction completely, the Torsen differential will be unable to supply any torque to the other set of wheels. The bias ratio determines how much torque can be transferred, and five times zero is zero.
This is what GM uses in the trucks

[spudglo08]

That is how AUTO 4X4 works also
The silverado SS has Viscous Coupling http://auto.howstuffworks.com/differential9.htm