Adding a Eaton G-80 to a 2012 Truck - I have a GMC sierra 2WD and would like to know if it was possible to install a Eaton G-80 to ...

I have a GMC sierra 2WD and would like to know if it was possible to install a Eaton G-80 to it , i want both of the back tires to move and not just the right back one, anybody know if you can add it ? Does anybody know what kind? Where i can find one? thank you

It can be done. It may be cheaper to find a rear end at the junk yard that already has it and has the same gear ratio as your truck and put it in. You can get everything you need to put one in your housing from the dealer in your area, or from a dealer who sells stuff cheaper on line.

How would I know what kind of gears I have ? It's a 2012 GMC Sierra 4.8

Look on your glove box sticker and get the "G" codes. Then look for the thread that tells you what the codes stand for. The "G" codes are for the axle and one will be what gear ratio you have. If you have the window sticker, it will tell you also.

GU4 is a 3.08
GU5 is a 3.23
GU6 is a 3.42
GT4 is a 3.73
GT5 is a 4.10

Ole tyler, comin through in the clutch! And make sure you dont have the g80 code... Mines a 2wd 2010 and it has the g80 already...

All you need to buy is the case + side bearings. Its always a good idea to replace the bearings as they incur the most wear when new or so I was told by a ace rear end man.

It should not make a difference in what the ratio is, you are not changing the ring and pinion, just the center case.

I did that on my 2001 GMC. Its going to cost you some $$, all said and done anywere from $400-$600 for the case alone + about 2 hrs installation (or less depending on the tech).

By case I mean the unit the houses the G80, everything else is the same. I shopped around local dealers and one sold it to me at wholesale, as long as they did they install.

No 6 in drawing. Note the prices for a G80 case.


[ 6 ] UNIVERSALS & REAR AXLE / REAR AXLE / DIFFERENTIAL / DIFFERENTIAL CASE
differential case Silverado, Sierra; 9.50; 2WD; w/o Limited Slip
MSRP $658.98
[ 6 ] UNIVERSALS & REAR AXLE / REAR AXLE / DIFFERENTIAL / DIFFERENTIAL CASE
differential case Silverado, Sierra; 9.50; 4WD
MSRP $380.79
[ 6 ] UNIVERSALS & REAR AXLE / REAR AXLE / DIFFERENTIAL / DIFFERENTIAL CASE
differential case Silverado, Sierra; 8.50, 8.625; w/o Limited Slip
MSRP $367.81
[ 6 ] UNIVERSALS & REAR AXLE / REAR AXLE / DIFFERENTIAL / DIFFERENTIAL CASE
differential case Silverado, Sierra; 8.50, 8.625; w/Limited Slip
MSRP $793.81
[ 6 ] UNIVERSALS & REAR AXLE / REAR AXLE / DIFFERENTIAL / DIFFERENTIAL CASE
differential case Silverado, Sierra; 9.50; 2WD; w/Limited Slip
MSRP $793.81
fyi - The 9.50 axle is only in the max trailering and with the 6.2L engine
Note - Do not let the Limited Slip throw you, its just a data input error and its reall a Locker.
I got the info HERE

Machster69 wrote:Ole tyler, comin through in the clutch! And make sure you dont have the g80 code... Mines a 2wd 2010 and it has the g80 already...

If the OPs already noticed one tire spinning, I'd say he probably doesn't have it yet.

Worthwhile upgrade. As mentioned, you can probably get a rear end off a wrecker for cheap. The install might run a bit if you don't do it yourself.

I bet the salvage yard wants a pretty penny for a G80. They know the value. If its a complete axle asm it could cost more then a new case. Parts off new trucks sell at a premium but its worth a try.

I called a buddy who runs the local salvage yard. He did not have one but could locate. He said the going price was $750 for a complete G80 axle assembly but he would not guarantee that price because he has to go on the locator and have it shipped.

Little more than I expected, it would appear the new case parts vs. the full assembly is potentially a wash ($750 vs $800). In that case I'd push for the new components like Mike....little safer to buy new and place in an axle you know the history of rather than risk a slightly dinged one from salvage.