Chevy Astro and GMC Safari Forum banner
21 - 38 of 38 Posts
Mmusicman said:
tungtide said:
At the junk yard I simply turned one wheel, and when the opposite side spun along at the same time it confirmed to me that the door sticker was correct and it did indeed have a G-80..
I was under the impression that a "G80 locker" didn't engage (spring loaded) until one wheel spun at a certain rate of speed... something like 10mph? No lock on slow turns however.
That's what i pointed out earlier: It appears, that there are more than one systems, used in the G80. Mine is the locker, but in Metalvan's picture, it is some sorta LSD. That's why the wheels of tungtide's rear end spin in the same direction, whereas the locker operates, as an open diff, untill a difference in torque, btwn the two wheels, at a predefined speed of spin is applied.
 
Yes, I have seen videos ( we know this, right? ) of the distinct 2 different varieties of these special diffs.

Quite different from what I thought of as a "Locker". Then there is the "Locking Hub" - usually front - thing.

Then, then , then. The Experts will no doubt - clear it up. Gov-Loc, Eaton, OEM, G80, G80 Locker, LSD ( NOT the orange barrel variety ), Open Diff, Closed Diff, etc etc.

Soo many terms, so much time.

"No oil allowed on the ground" or whatever - that is so fun a statement.

Mike
 
Most people refer to the G80 as a Limited Slip differential, not a locker.
 
https://www.eaton.com/us/en-us/catalog/ ... ocker.html
Eaton said:
Reliable - Fully automatic engagement
Simple integration - Compatible with existing vehicle stability systems
100% Locking - Equal torque to both wheels
Eaton calls it a locker, that is what I call it as well.

I think maybe some of the confusion could stem from other GM car models that used the G80 code and actually had a limited slip differential in it. :shrug:

GM said:
"The G80 locking axle provides a greater traction advantage than limited-slip differentials in most situations, while its automatic engagement requires no driver involvement, unlike some competitors' electronic lockers, which require driver activation," said Jeff Luke, executive chief engineer.
"The G80's simplicity, durability and sure-footed grip have been proven with generations of customers, as it has been a staple of the Chevy truck lineup for more than 40 years.
Order options from my 03 Astro:

Other aftermarket traction adders for our vans https://sites.google.com/site/astrosafa ... ferentials

LOCKING DIFFERENTIAL LUBRICANT (SERVICE INFORMATION) #91-4-109 - (Aug 15 said:
SUBJECT: LOCKING DIFFERENTIAL (G80) LUBRICANT - (SERVICE INFORMATION)
VEHICLES AFFECTED: ALL LIGHT TRUCKS EQUIPPED WITH G80 REAR AXLE ALL YEARS
Some light duty trucks equipped with locking rear axles (G80) may exhibit rear axle chatter, especially when turning a corner from a stop.
This condition of alternate engagement and disengagement of clutches in differential assembly is usually caused by contaminated axle lubricant.
To correct this condition, drain and refill the rear axle with SAE 80W-90 GL5 (P/N 10950849). The use of any additive in locking rear axles (G80) is not recommended. Rear axle additives are designed for use in limited slip differentials which are normally installed in cars. All light duty trucks equipped with RPO G80 make use of a locking differential and the use of additives will delay the engagement of the locking mechanism and may decrease axle life.
VEHICLES/COMPONENTS INVOLVED: ----------------------------- Some light duty trucks equipped with locking rear axles, RPO G80
 
konybravo said:
astrometalvan said:
This is the factory Eaton G80 used in our Astro/Safari:

View attachment 2
I'm not sure, whether I am misreading the picture, but it looks like, there are several g80 set ups, because, what I see in the picture is an LSD, whereas mine looks like this:, which is the locker. Probably, it Is worth it putting this in a separate thread, since, if I recall correctly, there's beenn a dispute over it, and has never been verified?
Your response made me curious because our Astro was a 100% stock soccer mom van with the G80 in the RPO sticker, so I did a little research and found there are different series of G80's.
Some have a small window on one side and large window on the other side, some have 2 large windows.
Each series has slightly different shoulder shape, but all are more squared off than the bell in an open diff carrier.
In the pic of ours, the carrier is turned around to the small window side, but you can see the bolt heads in the shoulders.
LSD's have springs visible in every pic I could find, ours doesn't have springs.
 
Mmusicman said:
tungtide said:
At the junk yard I simply turned one wheel, and when the opposite side spun along at the same time it confirmed to me that the door sticker was correct and it did indeed have a G-80..
I was under the impression that a "G80 locker" didn't engage (spring loaded) until one wheel spun at a certain rate of speed... something like 10mph? No lock on slow turns however.
I have watched a bunch of videos on youtube about lockers, posi's, and open diff's in the last year while building a Jeep ZJ project. Some videos were from Eaton, some from independent testers.
I don't remember which specific video it was or I would include a link.
I remember one of them saying the G80 locked in with a 100 rpm diff in axle speeds. That may roughly translate into 10 mph.
 
I currently own just about every diff combo mentioned in this thread. Open/open on mammas awd Buick, G80 Gov-bomb rear/ open front on my Zr2 and twin torsens in my Safari. The G-80 is hardly worth the swap effort. The design with its centrifugal weights and pawls is a bomb waiting to go boom. They disengage at 25 mph so your back to open at speed. Find an Eaton torsen on eBay and never worry again. I probably have one rolling around in my shed
 
Captn.Crunch said:
I currently own just about every diff combo mentioned in this thread...G80 Gov-bomb rear...The design with its centrifugal weights and pawls is a bomb waiting to go boom...
Did yours ever go boom?
 
Mmusicman said:
Captn.Crunch said:
I currently own just about every diff combo mentioned in this thread...G80 Gov-bomb rear...The design with its centrifugal weights and pawls is a bomb waiting to go boom...
Did yours ever go boom?
now that I'm old and wise-er I don't flail on my machines like I used to so no mine hasn't gone BOOM! I treat my Torsens a lot harder than I treat the G-80 in the Z for sure
 
Well that is the honest answer I was hoping for.
Each has limitations and intended purposes... pros and cons.
I imaging most people do just fine with the G80 locker when not pushed or abused.
Not everyone likes to clunk while cornering.. the G80 has the smoothness of an open rear, but locks when needed.
I would definitely consider it for my 2000 4x4 van (which is driven easy) .. but not my 92 V8 hot-rod van.
 
Mmusicman said:
... I would definitely consider it for my 2000 4x4 van (which is driven easy) .. but not my 92 V8 hot-rod van.
Music, I am really interested in your 2 statements there - mind elaborating ?
I went and looked at costs, pics, text, terms, uses, ad nauseum... ( picture Mike looking shit up :eek: ).
$250-$350 seem reasonable - obviously some will swing both ways ( no, not like that )
Course, you need to know what you're doing and have a "few tools" and be a man or a woman.

What if you want to "nail it occasionally" on pavement - but you're definitely not a "Randy Racer" ( and he and all of us know what I mean ).

And on to your 92 - what did you have in mind?

I can't wait till I have to make the "crush washer or shim kit / measure" Decision.
Thanks in advance, Mr. Music / Hate where ya' live and all the Mean Photos You Post. LOL

Mike

ps: just went back and read Capn's post - pretty telling statement also.

..."now that I'm old and wise-er I don't flail on my machines like I used to so no mine hasn't gone BOOM! I treat my Torsens a lot harder than I treat the G-80 in the Z for sure"
 
sixsix said:
Mmusicman said:
... I would definitely consider it for my 2000 4x4 van (which is driven easy) .. but not my 92 V8 hot-rod van.
Music, I am really interested in your 2 statements there - mind elaborating ?
And on to your 92 - what did you have in mind?
My 2000 is driven easy and rarely needs posi-traction. But when it does.. it would be typically easy off-road conditions where a G80 locker would lock reliably under normal conditions as expected. I don't beat it up... a factory unit should be fine.

My 92 however, gets pounded on fat rubber on pavement behind a strong hole-shotted V8. A G80 locker would probably explode, by it's very design. I will be looking for some form of typical limited-slip or posi more intended for high horsepower racing abuse.

The right unit for the right job. :D
 
21 - 38 of 38 Posts