Is my AWD Escalade rearend junk?

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I think the G80 lockers work in a different way. Allows 1 wheel to spin so much then locks up mechanically. That may be why when spun by hand the wheels spin different directions like an open differential.

Now my mustangs with the Trac Loc differencial that uses clutch packs, I have rebuilt them tighter with more clutches and will spin the wheels in the same direction with the rear lifted and turned by hand

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02Lightning

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Thanks, great to hear that. Both tires do rotate in the opposite direction just like a standard posi does. I never tried the fronts. I guess the GM AWD transmission must lock the front wheels when in park. I guess these rigs are always in basically full time four wheel drive, unlike other vehicle manufactures that bias most of the power to the rear wheels and only activate the front wheels when traction is needed.

If that is the case, wonder how the vehicle can lock into park if all the wheels turn?

Mike

I thought all traction locks both tires spin the same direction? You also have to remember this is all going through a transfer case.
 

Rocket Man

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Pretty sure this is normal. One note is do not put it on jack stands and run it in gear for more than a minute or two unless you find out for sure if it doesn’t wreck the transfer case. Not sure on the NNBS but on my NBS Denali it will destroy the TC. You should go ahead and pull the rear cover and inspect it but make sure to remove the fill plug first. Quite a few people have drained the diff and then discovered the fill plug was seized and there was no way to refill it. Somebody else should chime in regarding running it on jack stands.
 
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73TA

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According to my vin# search, my ride has a limited slip, posi rear end, and the front is an open diff.

I did bunch of google searches and could not find much on the subject until I remembered to look at the vin info. Can't remember if the wheels spun in the direction on the stands.

Pretty sure there is something wrong with it, if the driveline is locked in park and the both rear tires spin. Guess I will find out when I get back home from my business trip next week and put up on jack stands and see if the rear wheels turn when I put it in gear.

Mike

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Do you have "G80" on the RPO sticker in the glove box? Every option your truck has is listed on this with a 3 digit code.

Looks like this, here's mine.....

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8f8643b72a2112764ede5414e28893c7.jpg
 
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swathdiver

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According to my vin# search, my ride has a limited slip, posi rear end, and the front is an open diff.

Mike, this differential does not operate like that in a '73 Trans Am or '87 Buick, it is a combination limited slip and locker. Runs more like a locker. No special fluids needed.

Remember, your AWD transfer case operates much like a 3rd differential carrier as well. You can down the Restoration Kit from GMs website for your vehicle and if memory serves there are detailed explanations on how the system works, same with the online shop manual at AllDataDIY.
 
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73TA

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I realize the true options are in the glove box and understand the GM G codes for the rearends. I had used the vin search before I bought to see what options where on it. I will the wife check the glove box.

Regardless of the rearend type, shouldn't the rear tires not spin if the driveshaft is locked in park as the case with my Esky, and shouldn't the rear tires spin at least a little if rear tires are in gravel?

This just doesn't make sense to me.

Mike
 

mikeyss

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My 09 tahoe has the AXN 9.5" G80 rear end, and when the vehicle is up on the lift, the rear wheels DO spin in opposite directions. While it's still on the lift, you can spin one tire as fast as you can by hand, and it will engage the locker with a loud clunk. It's kinda alarming when it engages and it's kinda hard to do by hand.
 

thompsoj22

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Thanks, great to hear that. Both tires do rotate in the opposite direction just like a standard posi does. I never tried the fronts. I guess the GM AWD transmission must lock the front wheels when in park. I guess these rigs are always in basically full time four wheel drive, unlike other vehicle manufactures that bias most of the power to the rear wheels and only activate the front wheels when traction is needed.

If that is the case, wonder how the vehicle can lock into park if all the wheels turn?

Mike
Pretty sure you have an open diff G80 in the rear which will rotate the op wheel in the
I realize the true options are in the glove box and understand the GM G codes for the rearends. I had used the vin search before I bought to see what options where on it. I will the wife check the glove box.

Regardless of the rearend type, shouldn't the rear tires not spin if the driveshaft is locked in park as the case with my Esky, and shouldn't the rear tires spin at least a little if rear tires are in gravel?

This just doesn't make sense to me.

Mike
Has the vehicle ever rolled down your driveway when in park with all four wheels on the ground? You have answered your own question. A true locker would not rotate in your test method of being jacked in the air. Your diffs are open and will do exactly what yours are doing when jacked up. If you actually have a true limited slip, lift only one wheel off the ground and you should have enormous effort req to spin the wheel. limited slip clutches wear out, if the wheel spins easily you either have a G80 tracloc or your limited slip is showing the result of 234k miles of urban use.
 

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