I have two G80s in my Blazer and my wife's Jimmy. I think they are great, but some others have posted bad things showing one that has busted.

I think we need to get some numbers on "GOOD" and "BAD" to see if the broken ones are out of porportion with other rear-ends.

User Name Year G80 Good or Bad?

Billbobagns 98 Yes Good
Billbobagns 99 Yes Good
86blazer327 ?? Yes Bad (video shows busted)

http://www.youtube.com/watch?v=AjymmXvBYsI

Good video showing how well the G80 works compared to Ford Dodge and Toyota

This has been discussed before, but not really in terms of how many people have had problems with the G80 diff. I have had a number of vehicles with the G80 and none have had any problem with them.

'00 Bravada - Good
'04 Rainier - Good
'04 Tahoe - undecided (I get some clunking back there but haven't had the time to pull it apart yet)

And I know of many more friends/family that have them without issue:
Dad's '94 K2500 - Good - This truck was ABUSED every day of its life and went through 2 engines and 3 transmissions on the farm before it was retired due to body rot.
Dad's '04 K2500HD - Good - Same abuse as the '94 and still alive and kicking on all original drivetrain.
Dad's '08 K2500HD - Good - 3 years worth of hauling around a 25k pound backhoe in and out of fields on the flatbed with no sign of a problem.
Dad's '11 K2500HD - Good - New so time will tell.
Friends '01 Bravada - Good
Friends '99 Bravada - Good
Uncle's '99 Sonoma - Good

I'm sure I can come up with more if I thought about it.

this has been done before... just search g80 and look at the plethora of opinions...
G80 is not a LOCKER it's a locking diff.... huge difference!

the Gov Loc was bad because wit was machined with bigged interior holes and weaker materials. That teamed up with the vehicles people were dropping them in at the time and you get the idea.

The updated and improved G80 "Eaton Locking Diff" was redesigned to be more durable.

The hot rodders who have dubbed the Gov Loc the "Gov Bomb" did so because they were dropping them in 10 bolt Camaros, Chevelles, Novas, etc with rodded out engines. OF COURSE they will fall appart under those conditions. The have fly weights that kick in when one wheel spins faster than the other (to the tune of 100 rpms i believe).

When you are trying to launch off the line in a race with the pedal dumped, and your drive wheel gets squirrely, the g80 kicks in and attempts to LOCK the diff so the other wheel can get in on the fun, delivering drive power to both rear wheels.... unfortunately (for the g80's rep) this does not work well when you are attempting a 13 sec or less 1/4 mile run. BAM! you have a grenade in a 10 bolted package.

So if you are trying to figure out if yours are good, it depends on their condition and how you drive with it...

I am not aware of anyone posting pics of bad ones (other than me) in a thread regarding what to look for in a broken one.....
*BONUS* those pics were borrowed from HOTRODDING websites :icon_doh:



sorry if this is turning into a rant. :icon_steer:
main points:
^ gov loc = bad....
^ g80 (been around for like 35 years or so) = good FOR IT's PURPOSE
^ putting a g80 in your suped up 85 Iroc with a blower and "full F*in race cams" (Boogey Nights) will lead to problems since you are cheaping out on something you should not be.

clear enough? again sorry... :icon_hide:

Mine
'00 Blazer - Bad. As far as I can tell it's toasted. :icon_shrug:

Friend's and Family
Brother-in-Law 91 Blazer - Good
Friends '03 S10 - Good
Father-In-Law 03 Silverado - Good

The original one I had in my 99 didnt work. The one in the ZR2 rear end that i put in works great. Other than the first one they seem to be ok. If i just had an open diff the G80 would not be on the list of locker options. Due to them wearing out and are expensive to replace and its not an actual locker.

My 02 Jimmy it worked good in regular conditions, not so good in more of an extreme offroad situation.
My 98 ZR2... well it never worked.

Now the detroit lockers I have now.... Amazing, but its a whole different playing field.

Perhaps I should narrow down the scope of this survey;

G80 in a normal Blazer type operation; Best locker in the world or Bomb?

A poster named 86blazer327 posted a video showing the carrier of a G80 busted and he says they all bust around 160,000. My two vehicles would argue that case.

Let's not discuss hot-rods or rock-climbers, let's keep it Every Day Drivers.

My experiences are all good!

Before anyone can say the G80 Locker is not a Locker, they need to "Define a Locker".

If a Locker is a diff which can "Lock" both axles together in a challenging situation, I'd argue (and Eaton and GM seem to agree) that the G80 is clearly a Locker.

Again, normal driving of a Blazer, mud, snow, ice, good traction, pulling a boat, helping someone out of a ditch.... Good or Bomb?

I say "Best diff I've every used"

'93 Bravada - Good

Ok, fair enough. G80 is not a locker.
Definition: A Locker is when both axels are locked together via gears or friction plates so that both tires are rotating the same amount regardless of turning radius or having a lifted tire, etc. allowing for NO slip, not limited slip. Lockers are generally selectable or automatic (full time).

G80 is a locking differential aka Posi-traction or limited slip differential. very VERY different. meaning it is a full time open diff, that can send power to the other wheel on the drive axel when certain conditions are met (loss of traction).
ANot gonna touch that one.

I am not trying to be a prick or anything. I am just trying to clear this up for future use of this page both in search and for the current readers... :icon_hide:
it has been done before in the forum. Posi-traction was out before the GovLoc. After the GovLoc, other makers got on board with their own locking diffs. GovLoc was redesigned and re-named G80.


I'd agree with you there. the only other locker i have been around is full time Detroit built for a puller rig, and as i have never driven it, G80 is the best I have done as well.


And to mess you up some a little more things like the PowerTrax LockRight works as a full time locker, but seperates into an open diff while turning. it's a freak of nature that i want in my axle

So, given the 2 options of best ever or bomb, i guess i have to vote bomb since my in broken :(

not wantting to rant on like Curtis, i'd say the best way to sum it all up is this.................

if it came from the factory, and is in good working condition, then they are a VG set-up. but!........

if it ever fails.........you'd be a barrel of monkey nuts to pay the money for a OE one. but that's just my opinion. :icon_shrug:


personally, i've got a nice Auburn unit sitting in the shed for the day that my beautifully functioning G80 pukes all over the place-'cause it will happen! i'm just surprised i haven't done mine in yet-and that's saying alot!!!

I'll be putting in a Detroit Tru-trac in my Tahoe if the G80 goes out on me.

As far as the definition of a locker that is given, strictly sticking to said definition means that the Detroit Locker isn't a "locker" since it has the ability to unlock while turning and not under power. The G80 will completely lock up, but it does take wheel spin to lock it up; hence the term "Auto-Locking differential". The same goes for the "Selectable Locking Differentials" in that they can be open until requested to lock up. Basically, why would the definition state anything about gears or clutch plates if it were to mean that both axles would be permanently locked together. That there is the definition of a spool if you take out the gears/clutch parts.

It's semantics really and has been discussed 'ad nauseum' in the past.