I was curious about the new G-80 rear end. What has changed , and what makes it superior to the older governor lock style differential?

I dont recall where I read the decription. but the last info I saw was that the design wasn't changed but made stronger when the switch to AAM rearends was made. I've got a 93 Z-71, 99 tahoe and an 03 Dmax, This Gov lock seems to react quicker than the others did when new. I've only had one problem with the Gov locks which was my fault towing to much weight on a dirt road in my 93 1/2 ton. the case cracked and parts went everywhere and took out the whole rearend. that was with 120,000 miles on it so I guess it lasted along time the way I drove it.


If ya find out anymore please post the info. I'm considering changing to a E-locker in the 03 so I can control when it locks.

For what it's worth... I've noticed a substantiol differance from my '02 and '04 locker rear ends.


The 02 would chatter and grag at the oddest of times. The 04 is very smooth and I hardly know I have a locker.


cmc

IF you get a GMC it has an Eaton electronic locking unit looks like a coil locks the two axles together until 20 mph look at Eaton.com

IF you get a GMC it has an Eaton electronic locking unit looks like a coil locks the two axles together until 20 mph look at Eaton.com


So is the Chevy different?

IF you get a GMC it has an Eaton electronic locking unit looks like a coil locks the two axles together until 20 mph look at Eaton.com


So is the Chevy different?





Looks as both are the same;


Chevy:


Standard: GT4 Rear axle, 3.73 ratio
Option: G80 Differential, locking, heavy-duty, rear


GMC:


Standard: GT4 Rear axle, 3.73 ratio
Option: G80 Differential, locking, heavy-duty, rear


Also there's a GT5 rear axle, 4.10 ratio for Chevy and GMC, but it's not availble with the Duramax (I wish it was). Edited by: Voodoo

I do not have one.http://www.dieselplace.com/forum/smileys/Cry.gif


How much more was this option?

On my '01 it wasn't much, I think it was only about $200 extra. have to check the sticker in the file.

My 01 was $295, and I would have gladly paid another $295 for one in the front too.....if it was availablehttp://www.dieselplace.com/forum/smileys/Angry.gif


JP

I do not have one.http://www.dieselplace.com/forum/smileys/Cry.gif


How much more was this option?





NoWake,


You don't really want to know the answer to that one do you?


The retail on the option was $295.00. But, if you ordered the HD package, it included the Duramax, the Allison for $1200.00 and the Eaton for a total of $1500.00 extra, then there was an HD package discount for $1000.00. So you got the Allison and the Eaton for $500.00 by ordering the package instead of individual options.


I didn't find that many trucks around here to look at, but all of them had the HD package with the Eaton and the discount.

I do not have one.http://www.dieselplace.com/forum/smileys/Cry.gif


How much more was this option?





You should have one, very few if any Dmax's came without one,unless specially ordered from what I've seen on window stickers at the lot. If by chance you don't have one and want to install something. You should go with after market, Detroit locker or an Auburn posi. or similar types. These are Much stronger than the G-80 govlock and it only works as a locker upto 20 mph. It's also questionable with tires over 33 or 34 ". I believe you can get a Detroit locker for the AAM 11.5 for around $400 or $500 dollars. Buying a factory govlock from the dealer will run over $600 or $700. Just my opinion pick any four by four magazine and do your own research. If ya dont have a locker you'll be amazed at the difference in snow or mud with one.

http://www.dieselplace.com/forum/smileys/Clap.gifhttp://www.dieselplace.com/forum/smileys/Clap.gifhttp://www.dieselplace.com/forum/smileys/Thumbs Up.gif


I have one!!!! I looked over it when I checked my sticker! Today was the first day it was in snow and ice....what a difference it makes!!!!http://www.dieselplace.com/forum/smileys/Clap.gifhttp://www.dieselplace.com/forum/smileys/Clap.gif

Does anyone know if the G80 is any different from previous GM Lockers? I had seen a post somewhere, That said it was a superior rear end . How long have they been using an Eaton unit?

My 93 has it, it was originally made for the military cudv trucks maybe as far back as the 80's. a civilian option from atleast 93.

Anyone know what changes have been made along the way?

My 90 Chevy Z71 has the Eaton locker in it and I broke the ring gear during a WOT moment...?...anyway, the gear that the gov-lock turns to lock in the posi has several teeth missing and looked to be made from a cheaper alloy. I just replaced the ring and pinion and left the locker part alone, so having it lock in is just hit or miss. Sorry to ramble....I just hope they have a better design.

I had a '94 Z71 that had the heavy duty suspension package on it. It was a 1/2 ton truck, That had the 14 bolt rear end up under it.It also had heavier torsion bars. it was a $250 option that was well worth it! It was different from the 2500 series trucks , Because it still had the 6 lug axles. It was the Governor lock differential. Now that I have this new 2500 HD Duramax, I was curious what I had up under there. I haven't crawled up under it to look yet. I know it's a heck of a lot heavier looking than the 14 bolt. I am wondering if they use the alluminum drive shaft on the 2500 HD's? I'll be crawling under there to look around when the weather clears up around here. I've been riding around in the sleet and ice for the past 2 days. It sure is nice to have some decent tires and a 4X4! Thanks for all the info so far-

Gov-lock goes WAY back. Dad's 1982 C-10 has it, and it still works today. Never was as smooth as the newer ones though, it allows more slip before locking and locks more abruptly. His is in a 10-bolt GM corporate axle with 2.73 gears, behind a 250 I-6 and TH-350 tranny with a lockup torque converter. You only notice the locking action with one or both wheels on ice, because that's the only time the 92 HP can slip a tire.





The old beast is as reliable as sunrise and gets 20+ MPG, which combined with the 40 gallon fuel capacity gives it serious long range.

Well I am sure the ice will lock them up fine, but wet or steep boat ramps and wet roads going around a slow turn will too. I've had mine lock up in both of these situations, the slow turn on wet spot in the turn made for some excitement! SIDEWAYS!

If you look at the 04 Sierra book from dealer showroom it says 1500,2500,HD, series have an Eaton electronic locking rear Diff. it says Sierra is the only truck that has this feature in 04. I have not looked at my Diff. to see if wires are coming out of it yet My window sticker only states "locking differential-rear axle"

I did a google search on it and found this info on the G80--- http://www.torquecontrol.eaton.com/prod2.htm

The G80 is a mechanical locker. It is not electronically controled. My wifes 2001 Yukon XL 2X4 was special ordered to have one, as was my 2002 2500HD CC D/A 2X4. I can't speak for the 2004 models as to wether or not the G80 locker is now electronically controled or not, but my educated guess is that it is NOT. If there is an electronic locker on a Pickup, it's probably a special order item on high end 4X4's and only available on the FRONT DIFF. And it is computer controlled. No way would you want the average Joe throwing a manual switch and forgetting to disengage it on the pavement. You would not be able to steer the vehicle if the front diff was locked, and you would drag one of the rear wheels every time you turned a corner if the read diff was locked.





Quote from the web page mentioned above:


Where can I buy a mechanical locker?


The Eaton Locker is option code G80 Locking Differential on GM light trucks and SUV's. Go to Chevrolet (http://www.chevrolet.com/), GMC (http://www.gmc.com/), Cadillac (http://www.cadillac.com/escalade/index.htm) or Oldsmobile (http://www.bravada.com/) websites for more information.





Notice the word "mechanical locker" and option code G80......... case closedhttp://www.dieselplace.com/forum/smileys/Big Smile.gif





Oh and to answer the original posters question.............. I don't think it has changed since it's introduction. A locker is just that, it acts as an open diff until slip is detected and then it "locks" the two axles together with zero slippage. A posi trac (which GM no longer offers) uses clutches which are always engaged to try to tie the two axles together while still allowing enough slippage to allow the axles to turn at different speeds when you make a turn. The problem is that it is still traction limited when you get in situation where one wheel has great traction and the other has almost none..... sometimes the posi will slip so bad the the wheel with traction will not move, but the other will spin wildly. With the locker, you have both axles & wheels turing the same speed regardless of which one has traction. This is why all of us offroaders (I have both a 79 & 80 model Dodge Ramchargers 4X4's , 100% offroading only) have lockers and not posi's in both axles. The rear is a mechanical locker, and the front is an air activated locker (ARB locker).


Edited by: Searay90

Searay90 is right. Only the front diff is electronically controlled. The rears are mechanical only. GM does not have any electronically controlled rear diff available for any truck, not even high end ones.

On page 9 of the GMC Sierra literature it says that an electronic locking rear differential is available for Sierra 1500, 2500, and heavy Duty trucks. It says it senses wheel spin, locks the rear axle and transfers torque to the rear wheel with more traction. GM trucks are the only trucks that offer this differential.





JS02


99Z71

After some investigation I found that GM/Eaton does have an electronic rear diff. It is push-button and available in the H2.


http://www.media.holden.com.au/division/2003_prodinfo/pdf/hummer/03_HUMMER_H1.pdf


Still havent confirmed it's availability in Sierra/Silverado or if it's push-button or not. Will check and post findings.

The link above is for the H1 model not the H2. The H1 is the civilian version of the military hummer and yes you can get an E-locker in it.


Even if you find that you can get an E-locker on a Sierra, the option code will not be G80. Option code G80 is for a mechanical locker.

I believe the code would be G81. I'm told the E-Locker is available in the H2 as well. I'm still checking around on this and will post my findings. We really dont handle truck axles in my area, it's mostly new technology and AWD car systems that come through here.

My dealer called tonight to see how I liked my new LLy DA GMC,I asked him about the electronic Diff. he will call me back with an answer. I cralled under new truck and looked for any wires entering rear diff. no such luck only found vent going up around filler neck.