Locking diff? - Chevrolet Forum - Chevy Enthusiasts Forums
Georooney's Avatar
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December 10th, 2010, 11:02 PM   #1  
Locking diff?

My new (to me) 2008 Silverado LS 1500 is supposed to have a locking rear differential. How, if any, is this different from a limited slip differential?

Can somebody tell me how it works? I've driven the truck on slippery and loose gravel roads, and don't notice anything appreciable in the handling, ie: the back wheels still spin when I give it gas. I back off right away, so can't really tell if one or both rear wheels are spinning. (This is in 2-wd, by the way.) How can I tell if it's working?

Oh, and the dealer put in a new rear differential just before I bought the truck, didn't disclose that to me at the time of sale. The salesperson slipped and mentioned it when I requested the service records later. Is there any chance they put in a regular (non-locking) differential when they changed it out?


Thanks,

Geo

 
Mille Racer 69's Avatar
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December 11th, 2010, 1:44 AM   #2  
Well 1 way to tell if it is supposed to have locking differential is open the glove compartment and there
Should be a piece of paper stuck in there with a bunch of RPO codes, see if 1 of those codes reads "G80".
Iirc G80 is the code for a locking differential.
Or you could click the blue link in my sig line to check all your stock features.

To my understanding, you have 1 wheel spinning and when that wheel looses traction the other rear wheel
Starts spinning also. Mud is slippery, regardless if you have it or not you are still gonna slip.

 
DoubleO7's Avatar
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December 11th, 2010, 8:40 PM   #3  
Speaking "old school"
Limited slip means that when one wheel spins faster than the other, the mechanism inside the diff tightens up and transfers some power to the other wheel.
Locker or locking diff means that there is a mechanism in the diff that divides the power to both wheels nearly 100% of the time with very little differential between them.
However, modern definitions have been bastardized by the manufacturers.

How a G80 works:
http://www.youtube.com/watch?v=KbMZ9vcYVSg
A G80 "locker" demo video (about 40 seconds in):
http://www.youtube.com/watch?v=q-rQT...eature=related

If it had a true, old school Detroit Locker, there would be no initial single tire spin.

 
Georooney's Avatar
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December 12th, 2010, 10:06 PM   #4  
The list of option codes for the truck includes a G80-locking rear differential, which would suggest the truck originally had one. The rear diff was changed earlier this year (the dealer can't give me a reason why).

From what I've learned, the G80 locks up when one axle spins 100 RPM faster than the other axle. So putting it up on axle stands and turning the wheels by hand to see which way they go isn't going to tell me anything, unless I can manage to spin the tire at 100 RPM.

Guess my next step will be to find some soft ground (maybe pull the truck over so that one rear wheel is on the gravel and the other is on the pavement, and then try to spin out. wonder if I need to put something in front of the front wheels to hold it back a bit?

Unless somebody else has a surefire test for the G80?

 
BayAreaChevyGuy's Avatar
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December 13th, 2010, 12:08 AM   #5  
Are you thinking the jip'ed you out of what your supposed to have? Or just trying to figure out how your system works?

 
DoubleO7's Avatar
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December 13th, 2010, 10:24 AM   #6  
Posted By: Georooney Unless somebody else has a surefire test for the G80?
Jack one wheel up until it has no traction.
Now try to drive off the jack.

But take precautions so you do not run over someone or hiy something when the G80 kicks in and moves you forward.

 
Georooney's Avatar
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December 13th, 2010, 10:33 AM   #7  
Posted By: DoubleO7 Jack one wheel up until it has no traction.
Now try to drive off the jack.

But take precautions so you do not run over someone or hiy something when the G80 kicks in and moves you forward.

Ouch!!!

 
Georooney's Avatar
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December 13th, 2010, 10:39 AM   #8  
Posted By: BayAreaChevyGuy Are you thinking the jip'ed you out of what your supposed to have? Or just trying to figure out how your system works?
Not suggesting that they cheaped out and replaced the G80 with a regular diff, although I do wonder at why they didn't disclose that it had been changed. More that I wonder if it's working? The day after I bought the truck it snowed, and the rear wheels of the truck seemed to be breaking away each time I accelerated from a stop. I'll admit I was a bit heavy on the gas, coming from a 4-cylinder 5-speed manual to an 8-cylinder 4-speed automatic.

 
gotstylez's Avatar
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December 13th, 2010, 12:00 PM   #9  
easiest way is to pull off into some grass..and hit the gas..personaly i dont like the g80 my dads 06 had it everytime he got into some snow with 1 wheel and pavement on the other and gas it he would chirp the other tire when it started to spin.. which is why they call them garande 80's...because they explode on people when doing that

 
Georooney's Avatar
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January 2nd, 2011, 3:01 PM   #10  
OK, so here's the latest: the dealer says the 2008 Silverado LS doesn't come with the G80 locking differential, only the newer models 2010 and on. My spec sheet says it does. Who's right, the dealer or General Motors?

 
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