GM fullsize AWD Van Info thread

b. rock

Active member
I've been looking through dozens of ads, and having an FZJ80 the easy way to spot a factory locker option is the factory switch. I can't seem to see anything on any of the dash of the Express to indicate which ones do have the factory locker, and which ones don't. Outside of asking for a shot of the RPO codes on the glovebox, anyone have an easy way to tell which ones have the locker and which don't? I'd hazard a guess that most that got the locker also got the 3.73 diffs, but who knows.
 

b. rock

Active member
Tried that, didn't list the RPO codes.

So if there isn't an obvious switch to look for, it's not a selectable then? As in it's basically just part of the traction control system?
 

dleeallen

Adventurer
Just built into the differential. It's just a limited slip, not a selectable locker. So nothing to see. I thought it might list it out in the vin decoder under the equipment section. Bummer it doesn't.
 

vintageracer

To Infinity and Beyond!
I cant even tell if my own rig has a G80 locker. I am missing the glove box so no RPO codes :(
The SPID is not in the glove box.

On a GM van look on the right front passenger door below the door latch mechanism in the jamb of the DOOR for the SPID sticker which will list the option codes.
 
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Scotty D

Active member
No sticker in the passenger jam and no evidence there ever was one there. Mine is a 2009 Chevy AWD . I am pretty sure its all stock except it does really well in the sand so I always wonder
 

dleeallen

Adventurer
Just try to spin a rear tire next time you have it off the ground. See if they go the same direction or opposite. Same equals the limited slip.


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Scotty D

Active member
Does that also apply to the G80 auto locker since its doing its job with the ABS system?
I will try that tomorrow thanks!
 

dleeallen

Adventurer
Oh I think you are right that it won't work to test it like that. It takes a 120rpm difference to get it to lock up. Otherwise it is like an open differential.


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b. rock

Active member
Oh well that's good to know, thanks for the posts. I had always seen it referred to the 'locker', so already having a vehicle with lockers, that's what I was expecting. Not quite as critical as I thought then.
 

vintageracer

To Infinity and Beyond!
You are correct! Not sure how I was so misinformed. If mine does not have one, I would like to find one and put it in.
The factory G80 option is a "Limited Slip" type of traction device installed in the center carrier of the rear-end. It operates with clutch type friction materials engaging in the carrier and therefore is not directly mechanical in operation. They are OK however there is better.

Eaton makes several other choices for a true mechanical engaging type of rear carrier. There is the venerable "Eaton Detroit Locker" which is totally mechanical and basically ON/OFF. I used one for years in my Vintage Race Cars. Eaton also offers the "Tru-Trac" type of carrier which is mechanical in operation with conical gears. Eaton also offers an electric locking carrier similar to ARB however electrically operated versus air operation. Eaton also has a "Clutch type" rear carrier which is like the factory G80 option.

When checking applications for my van all were available. Amazingly my van did not have the factory G80 option so I installed a Eaton "Tru-Trac" carrier in my van. Mechanical option that works great and not as ON/OFF and is much smoother in operation than the Detroit Locker.

Below is a picture of the location I have seen most later model GM van SPID stickers.

20181130_135043_resized.jpg
 
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stuntman mike

New member
Hey Gang! I'm not ready to start my own build thread yet as I'm still researching and parts collecting for my newly aquired 2014 AWD Express. I'm currently tire shopping and considering my needs and options. How many folks maintain a 5 wheel rotation? As I'll be upsizing my wheels, a stock spare will be bad news. So if I'm going to spend the money on a fullsize 5th, I might as well utilize it, right?
 
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