Rear Diff Upgrade to eaton e locker

Morgoth604

Original poster
Member
Sep 15, 2012
18
ok so i went to get my rear diff fluid changed and the guy said there is a leak coming from where the drive shaft goes into the rear diff. i know its just a bearing seal leak. but its been a while and i just asked to service the whole rear diff and replace the broken parts and clean out the diff. now i like the G80, but i dont want to have to go through all this crap again later on down the line. so i started thinking what would be my options for a new locking diff and this is what i came up with.

1. another new G80.??? not really wanting that.
2. a new air locker diff from arb. can be expensive and needs a new rear end. so no.
3. i found this on eaton.com. its called the eaton Elocker. have you heard of this??????
Performance Products | Eaton ELocker

Eaton Torque Control Products 19659-010 - Eaton Electronic ELocker Differentials - Application - SummitRacing.com

(IF YOU CLICK ON THE OVERVIEW OF THE LOCKER IS TELLS YOU WHAT BEARINGS YOU NEED)

here are the specs i found on the eaton e locker:

gm 8.5 inch/gm 8.6inch
10 bolt pattern
for use with 30 spline axles
for use with 2.73 and up gears
needed for proper install new bearings (part#LM-603049 / part#Race LM-603012).

now my 2002 trailblazer 4x4 LTZ

all stock rear end, which means it has a 10 bolt rear end (8.6inch)
rpo code G80, which means it has the G80 diff.
it has 3.73 gears
i dont know how many splines it has though. im gussing its 30 spline.

Here is a video of how the eaton E locker works. i think youll agree that you want it. :smile:
[video=youtube_share;bnplleAycNY]http://youtu.be/bnplleAycNY[/video]

my questions is would this work for a G80 upgrade, without having to buy an entire new rear end assembly?
in other words, can i just swap out the G80 for the E locker?
 

RayVoy

Member
Nov 20, 2011
939
It won't be cheap, do you do any off-roading?

Good possibility it will fit.............in the rear.

But, there is a good possibility the existing G80 will last for as long as you plan to keep the truck.
 

bore_pig

Member
Nov 25, 2011
113
Why do you feel the need to replace more than just the bad seal?
 

BRomanJr

Member
Dec 9, 2011
371
Morgoth604 said:
now my 2002 trailblazer 4x4 LTZ

all stock rear end, which means it has a 10 bolt rear end (8.6inch)
rpo code G80, which means it has the G80 diff.
it has 3.73 gears
i dont know how many splines it has though. im gussing its 30 spline.

Unless it has already been upgraded, You will need to buy an 8.6 inch rear end for that e-locker. Most (probably all) SWB I6 trailblazers were produced with the 8.0 inch rear end. From what I remember, the 8.0 had different (28 ?) splined axles. The G80 option was produced for both sizes of differentials.
 

Morgoth604

Original poster
Member
Sep 15, 2012
18
BRomanJr said:
Unless it has already been upgraded, You will need to buy an 8.6 inch rear end for that e-locker. Most (probably all) SWB I6 trailblazers were produced with the 8.0 inch rear end. From what I remember, the 8.0 had different (28 ?) splined axles. The G80 option was produced for both sizes of differentials.

yup your abosolutly correct. i double checked with my mechanic, and he siad ihave the 8inch rear end. sucks casue that would be the best locker for our applications i think.because our 4wd drive swtich in the cabin above the rear window wiper only controls the front end diff and the transfer case. with this locker it would be the exact same as the front, you flikp a swtich and boom the rear is locked. no more having to make one rear tire spin to force it to lock. which over times breaks the springs inside which mine has done. thats why i need a new diff, and they stopped making the replacment parts for the diff its self. so i know have to buy a new diff. i wonder what rear end the trailblazer ss has? if the distance between the wheels are the same as the 8 inch rear end, and it has a 8.6inch rear end for the diff it would work, but youd need new axles at 30 spline and new splines for the drive axle or a whole new drive axle with one side 28 splines for the tranny connect and the other end 30 for the rear diff connect, then it would work.:thumbsup:
 

Short Bus

Member
Dec 2, 2011
1,906
You can get a 8.6 from a SWB 5.3 or any EXT/XL

Morgoth604 said:
i wonder what rear end the trailblazer ss has?

9.5"
 

BRomanJr

Member
Dec 9, 2011
371
Morgoth604 said:
yup your abosolutly correct. i double checked with my mechanic, and he siad ihave the 8inch rear end. sucks casue that would be the best locker for our applications i think.because our 4wd drive swtich in the cabin above the rear window wiper only controls the front end diff and the transfer case. with this locker it would be the exact same as the front, you flikp a swtich and boom the rear is locked. no more having to make one rear tire spin to force it to lock. which over times breaks the springs inside which mine has done. thats why i need a new diff, and they stopped making the replacment parts for the diff its self. so i know have to buy a new diff. i wonder what rear end the trailblazer ss has? if the distance between the wheels are the same as the 8 inch rear end, and it has a 8.6inch rear end for the diff it would work, but youd need new axles at 30 spline and new splines for the drive axle or a whole new drive axle with one side 28 splines for the tranny connect and the other end 30 for the rear diff connect, then it would work.:thumbsup:

The heavier 8.6 and the SS 9.5 can be mounted to your truck, they both fit. You do not need to change the driveshaft when going from 8.0 to 8.6, they are the same. When upgrading from the 8.0 or the 8.6 to the SS 9.5, I'm pretty sure the driveshaft is different.

No splines are involved where the driveshaft connects at the differential, the spline count refers to the inner end of each axle and where it slides into the carrier. That means axles from a 8.0 do not fit the 8.6 and vice versa.

And finally, both the 8.0 and 8.6 can be "open" or with the optional factory G80 "locker". The SS 9.5 is not a locker, it is "Limited Slip" (G86? - LS) .

In my situation, because My truck is only 2WD and I live in Michigan, I upgraded my 8.6 open 3.73 with a used 8.6 locker 3.42 for $400, works great. I would suggest this option as the 8.6 locker will be stronger and from what I've seen, you should be able to find one for $300-500
 

navigator

Member
Dec 3, 2011
504
if your G80 is toast, in your 8.0 rear your only option is another G80.
If you buy a rear that has a G80, you would need a carrier from an open diff to put in an aftermarket locker.
I think the G80 in the 8.0 is known to be on the weak side("grenade80") but I understand the G80 in the 8.6 rear is a little beefier. I'm unsure of any failures of the G80 in the 8.6 rear.

The best route is likely to source an open 8.6 and put in an aftermarket locker though.
 

navigator

Member
Dec 3, 2011
504
also, you have an older axle, they changed somewhere around 04-06, can't remember exactly but the ABS sensors changed. Make sure you sort that out if ABS is important to you.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
I did a 9.5 SS rear and swapped to an open carrier and a Lockright.

You need to source an open 8.6 and a locker or keep what ya got.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
navigator said:
also, you have an older axle, they changed somewhere around 04-06, can't remember exactly but the ABS sensors changed. Make sure you sort that out if ABS is important to you.

With his being older...any rear will let him retain abs.
 

Sparky

Member
Dec 4, 2011
12,927
FWIW I swapped an 8.6 into my truck when I replaced the axle due to some pretty horrific play in it. Bolts right up exactly as the old one came out.

I never popped the cover but maybe I should have just to see what the heck was going on in there lol.
 

Morgoth604

Original poster
Member
Sep 15, 2012
18
Sparky said:
FWIW I swapped an 8.6 into my truck when I replaced the axle due to some pretty horrific play in it. Bolts right up exactly as the old one came out.

I never popped the cover but maybe I should have just to see what the heck was going on in there lol.

so your saying that if i swap out my 8 inch rear end that is on the truck now, and install the 8.5 inch from the extended wheel base version, it should match up perfect with the suspension?. so i would not have to replace the panard bar and trailing arms. your saying it would be literally a matter of unbolting the old one and installing the new one???
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Morgoth604 said:
so your saying that if i swap out my 8 inch rear end that is on the truck now, and install the 8.5 inch from the extended wheel base version, it should match up perfect with the suspension?. so i would not have to replace the panard bar and trailing arms. your saying it would be literally a matter of unbolting the old one and installing the new one???

It is an 8.6 in the ext, but YES. The rears are interchangable without any mods except for a bastard ujoint and driveshaft length change if you go to the much bigger 9.5 from the SS.

The 8.0 and 8.6 are direct axle swaps. The ujoint, the control arms and panhard are the same.

FYI- the 8.6 also came in the V8 swb.
 

Sparky

Member
Dec 4, 2011
12,927
Morgoth604 said:
so your saying that if i swap out my 8 inch rear end that is on the truck now, and install the 8.5 inch from the extended wheel base version, it should match up perfect with the suspension?. so i would not have to replace the panard bar and trailing arms. your saying it would be literally a matter of unbolting the old one and installing the new one???

Bingo. The only difference between the 8.0 and the 8.6 is the pumpkin is a little bigger to hold the larger gear set as far as bolting it up and mounting is concerned. Width is the same, mount points are the same, etc.
 

bore_pig

Member
Nov 25, 2011
113
So are there measurements to take or a tag to read on the axle to know if you are getting an 8 or 8.6 and whether or not it has a G80? Or do you just have to take the salvage yard's word for it until you get home?
 

Sparky

Member
Dec 4, 2011
12,927
The diff cover on the 8.6 sticks out more than the 8.0, also the snout where the yoke is is a little bit longer with an extra gusset or such. But don't ask the junkyard for the size, ask them for one from the particular vehicle. Getting one off an EXT/XL will guarantee you an 8.6.

I should have taken pics of them next to each other to show the differences.
 

bore_pig

Member
Nov 25, 2011
113
How about G80? Gotta open it up to know for sure about that?
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
There is no external tag for the G80, but you can do a functional test at the junkyard. Just spin one hub about half as fast as you can. Until it locks up, the far side will spin opposite. It should lock up within 1/2 revolution with a quick flip, and you'll notice the pawls engaging if it had the G80.

Given time, it's best to open up the cover at the junkyard anyway unless you know the donor vehicle's mileage and assume there's no damage or wear.
 

JayPizzle

Member
Mar 26, 2012
9
I was thinking about doing the same thing (buy a locker) in my 05 Envoy 4x4. It does not have a G80 in it currently. Would I be in the neighborhood of needing a new rear end?
 

tblazerdude

Member
Dec 4, 2011
321
until someone with a open 8.0'' rear-end posts a "how to" on installing an aftermarket locker, your best bet is finding an EXT/XL rear end with the G80 (matching ratio) and swapping them. It will bolt right in, no other parts needed. If you could find one cheap enough or local enough, there is nothing wrong with throwing an 8.0'' factory G80 locker in instead of your 8.0 open. I have noticed there is little to no price difference in the 8.0 to 8.6 factory rear ends with G80 locking option. Check other posts to see the ABS sensor issue, which is very minor.
 

Morgoth604

Original poster
Member
Sep 15, 2012
18
tblazerdude said:
until someone with a open 8.0'' rear-end posts a "how to" on installing an aftermarket locker, your best bet is finding an EXT/XL rear end with the G80 (matching ratio) and swapping them. It will bolt right in, no other parts needed. If you could find one cheap enough or local enough, there is nothing wrong with throwing an 8.0'' factory G80 locker in instead of your 8.0 open. I have noticed there is little to no price difference in the 8.0 to 8.6 factory rear ends with G80 locking option. Check other posts to see the ABS sensor issue, which is very minor.

thanks i know there just a straight swap, out with the old and in with the new. as for the abs sensor the earlyier years like mine which is a 2002 dont have the sensor on the rear end. the sensors for the abs are on the front so that will not be a problem. the shop that fixed my truck went ahead of me and fixed the 8.0 with out my permission so i demanded that i get a 25% discount on parts and labour which i got so my reapir costed less than expected, but i still want to swap out my rear end though. but as of now its not very cost effective to do that seeing as they fixed the 8.0 already. so i kinda got scwred out of what i wanted to do. where i live there are 5 rear ends available all of them are 8.6's, so i know that ill be able to get one. my goal for the summer of 2013 is to try and to beat the hell out of the new rear end as the shop said that it would not break no matter what i did and i have a 1 year warenty on parts and service and they stopped making repair or rebuild kits for the 8.0 and the shop is unable to get them, so if i do break it theyll have to replace the rear end on warrenty and ive already checked with the junkyards in my area and all they have are the 8.6 rear ends. so fingers crossed this summer. maybe it will break and the 8.6 can be a b-day gift from the shop, hahahahaha. :thumbsup::wootwoot:
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
tblazerdude said:
until someone with a open 8.0'' rear-end posts a "how to" on installing an aftermarket locker, your best bet is finding an EXT/XL rear end with the G80 (matching ratio) and swapping them. It will bolt right in, no other parts needed. If you could find one cheap enough or local enough, there is nothing wrong with throwing an 8.0'' factory G80 locker in instead of your 8.0 open. I have noticed there is little to no price difference in the 8.0 to 8.6 factory rear ends with G80 locking option. Check other posts to see the ABS sensor issue, which is very minor.

Hard to post a "how to"for something that does not exist...

ABS issue is not minor. You can lose Stabilitrak and ABS function. Not something to be taken lightly.
 

tblazerdude

Member
Dec 4, 2011
321
HARDTRAILZ said:
Hard to post a "how to"for something that does not exist...

ABS issue is not minor. You can lose Stabilitrak and ABS function. Not something to be taken lightly.

That was kind of the reason I posted that. There is no aftermarket locker for the 8.0, correct? Could you take the internals out of a working 8.0 G80 and install them into an open rear end? I wouldn't do it since it would be easier to just swap axles, and possibly upgrade to the 8.6. The ABS issue is not relevant to trucks pre 2005. Any axle will work. So thats sounds minor to me. I have a 2004, I can use any year axle. :raspberry:
Plus doing your own research (not you hardtrailz, i know you know) would lead you to find that the ABS sensor issue would only affect drivers of 2005+, and they should only get an axle from 05 and up. I would want the newest, lowest mile rear-end anyway. We got off track of what has already been said. Acquire an 8.6 with a locker and install it. Found a free 8.6 with open diff? install an aftermarket locker. If i'm wrong with years or facts I encourage anyone to clarify, for my knowledge especially since I plan on buying any rear end with the factory G80.
 

Morgoth604

Original poster
Member
Sep 15, 2012
18
tblazerdude said:
That was kind of the reason I posted that. There is no aftermarket locker for the 8.0, correct? Could you take the internals out of a working 8.0 G80 and install them into an open rear end? I wouldn't do it since it would be easier to just swap axles, and possibly upgrade to the 8.6. The ABS issue is not relevant to trucks pre 2005. Any axle will work. So thats sounds minor to me. I have a 2004, I can use any year axle. :raspberry:
Plus doing your own research (not you hardtrailz, i know you know) would lead you to find that the ABS sensor issue would only affect drivers of 2005+, and they should only get an axle from 05 and up. I would want the newest, lowest mile rear-end anyway. We got off track of what has already been said. Acquire an 8.6 with a locker and install it. Found a free 8.6 with open diff? install an aftermarket locker. If i'm wrong with years or facts I encourage anyone to clarify, for my knowledge especially since I plan on buying any rear end with the factory G80.

if you have foud an 8.6 rear end, and you have an 8.0 right now, then yes i would upgrade to the 8.6 and id get the e locker from eaton. it is a great locker from all the reviews and people at eaton and others. if you have the abs sensor then make sure tyhe new rear has the abs sensor and youd be good to go. as a recomeddation i would change all the bearings so you dont have to change them down the road or even worse in the mountians. and yes it would be a straight up swap. if the new 8.6 you found has an open diff then the elocker should slid right in with no problem.:thumbsup:

i may have jumped off topic there, but for you tblazer dude, if the new has abs and your current has abs i would just swap out the old and in with the new, much easyier and cheaper. and no you can not use the old internals of an 8.0 on an 8.6. the spline are diffrent for the axles. so liek i said out with the old and in with the new. its literally a matter of un bolting the old and bolting up the new. as for the diff i would upgrade to the elocker, too many things can go wrong with the g80, or as i like to call it the gernade 80. the elocker would make our rear end just like are front end with push button locking, no more relying on wheel spin in the rear to lock the rear diff.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Morgoth604 said:
the elocker would make our rear end just like are front end with push button locking, no more relying on wheel spin in the rear to lock the rear diff.

You apparently don't know much about the front end. None of the factory fronts lock or are even limited slip. There is one aftermarket locker available and only 2 people running it.
 

Morgoth604

Original poster
Member
Sep 15, 2012
18
HARDTRAILZ said:
You apparently don't know much about the front end. None of the factory fronts lock or are even limited slip. There is one aftermarket locker available and only 2 people running it.

actually i do. the front is controld by the computer telling the tranfercase how much tourqe is put to the front wheels and applyies the torque by controlling the clutches to aply pressure to the clutchs locking the front and allowing the front to pull. as more power is applyed the more the front grabs. and im sure you already know that there isnt a front diff on our trucks, its a tranfer case controled by the tccm (transfer case control modual) which measures the speed diffrence between the rear drive shaft and front half shaft.:raspberry:

http://www.offroadtb.com/articles/tech-docs/transfer-case-tech-the-nvg-226-np8-theory-of-operation/

if you read the page above it will explain how the tranfer case turns the front wheels.

so unless you do a front ifs swap to a front diff. this is how your ifs works.
 

Sparky

Member
Dec 4, 2011
12,927
Morgoth604 said:
actually i do. the front is controld by the computer telling the tranfercase how much tourqe is put to the front wheels and applyies the torque by controlling the clutches to aply pressure to the clutchs locking the front and allowing the front to pull. as more power is applyed the more the front grabs. and im sure you already know that there isnt a front diff on our trucks, its a tranfer case controled by the tccm (transfer case control modual) which measures the speed diffrence between the rear drive shaft and front half shaft.:raspberry:

Offroadtb.com Transfer Case Operation: NVG 226 (NP8)

if you read the page above it will explain how the tranfer case turns the front wheels.

so unless you do a front ifs swap to a front diff. this is how your ifs works.

Yes there IS a front differential on our trucks. Have you never had the front driver side wheel off?

Look under the truck. There is a front drive shaft coming off the transfer case which is mounted to the back end of the transmission. That drive shaft goes to the FRONT differential, which then has one CV half shaft going to the driver side wheel, and an intermediate shaft going through the oil pan, to the splined disconnect on the passenger side, to the CV half shaft to the passenger wheel.

IFS has nothing to do with the front differential, aside from it being mounted in a fixed position rather than moving with the suspension.
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
Morgoth604 said:
actually i do. the front is controld by the computer telling the tranfercase how much tourqe is put to the front wheels and applyies the torque by controlling the clutches to aply pressure to the clutchs locking the front and allowing the front to pull. as more power is applyed the more the front grabs. and im sure you already know that there isnt a front diff on our trucks, its a tranfer case controled by the tccm (transfer case control modual) which measures the speed diffrence between the rear drive shaft and front half shaft.:raspberry:

http://www.offroadtb.com/articles/tech-docs/transfer-case-tech-the-nvg-226-np8-theory-operan/

if you read the page above it will explain how the tranfer case turns the front wheels.

so unless you do a front ifs swap to a front diff. this is how your ifs works.

Considering I have swapped my front differential to get lower gearing...you are severely mistaken. I have ifs and a front diff as all our 4x4 trucks do. Hell i have split the front diff case in half. I even keep a spare front diff along w spare cv shafts and a spare intermediate shaft and a spare disconnect and a spare actuator.
 

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