swathdiver
Full Access Member
The purpose of the video was to explain the locking feature of the differential, not the limited slip feature. Alternatively, you can read about how each feature functions in the Restoration Kits and the Shop Manuals.
Limited slip additive or not?
- Thread starter chauncey0337
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The purpose of the video was to explain the locking feature of the differential, not the limited slip feature. Alternatively, you can read about how each feature functions in the Restoration Kits and the Shop Manuals.
HiHoeSilver
Away!
The G80 is a limited slip differential that locks under certain conditions. It is made by Eaton and is nicknamed the Eaton "locker".
this ^^^^ . Use either Royal Purple or Mobil 1 Synthetic and you're good to go. They both meet the GM specs for these. I went with Mobil 1 and no problems for me.
Trailblazzin
Full Access Member
I’d like to read them, can you point me in that direction.
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swathdiver
Full Access Member
https://www.gmheritagecenter.com/gm-heritage-archive/vehicle-information-kits.html
Click on Suburban or Tahoe and select 2007 and maybe 2005 and some other years. Not all are as detailed as others. But it is in the 2007 for certain. As for the shop manual, you can get that via a subscription to AllDataDIY and or through SeriousCTBuyer on ebay in .pdf form in either a download or disc. I like having both.
OP
OP
chauncey0337
Full Access Member
Thank you everyone. I have not added the additive and don't think I will. Drove it 200 miles round trip and no noises. So I think I'm good. Thanks for all your replies and info. I've been on this site for 7 years and still learning new things.
From my experience ...it's doesn't matter at all. For instance Mobile1 75W-90 already has LS additive in it which doesn't hurt a non-ls diff. The G80 is a locking differential and is either engaged or not. It isn't a limited slip.
swathdiver
Full Access Member
Where do folks get this information?
Sorry. I meant the G80 gov-lok used in trucks. Obviously G80 has been used to denote for posi and limited slip diffs as well.
I was under the impression everyone knew I was talking about our model year when the only option was for a gov-lok G80.
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swathdiver
Full Access Member
What's a gov-lock?
Guess it's called MLocker now.
http://www.eaton.com/FR/Eaton/ProductsServices/Vehicle/Differentials/mlocker/index.htm
http://www.eaton.com/FR/Eaton/ProductsServices/Vehicle/Differentials/mlocker/index.htm
You do realize that article stated what some of us have been saying- it functions as a limited-slip differential until low traction conditions cause it to fully lock. So in essence it IS a limited-slip as well as a full locking differential.
HiHoeSilver
Away!
swathdiver
Full Access Member
Right! That's the same type center section that's been used in our trucks since at least the GMT400s and probably earlier. That Eaton link also confirms what Mark is saying, it's a limited-slip and a locker.
Interesting. Good info here. Didnt mean to say anyone was wrong here. Im just saying from my understanding of how the lockup ramp feature works...it is either engaged or not. sure the clutches can grab and chatter like an LS but that doesnt mean it works like a LS where progressive mounts of torque are transfered to the non slipping wheel. I'll read that article but I'm pretty sure about it unless things have changed in the last 10 years since owning a GMC Envoy and Sonoma with it. You learn something new everyday!
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Here's what Eaton says in that article, so there's no confusion.
MLocker (G80) Operation
During normal driving conditions, the MLocker (G80) functions as a light-bias limited slip differential. When a low-traction situation occurs that causes a wheel speed difference greater than 100 RPM, a flyweight mechanism opens to engage a latching bracket. The stopped flyweight triggers a self-energizing clutch system, forcing a cam plate to ramp against a side gear. Cam plate ramping will continue to increase until both axles turn at the same speed (full lock), which prevents further wheel slip. When the need for improved traction is gone - unlocking occurs automatically and the differential resumes normal operation.
MLocker (G80) Operation
During normal driving conditions, the MLocker (G80) functions as a light-bias limited slip differential. When a low-traction situation occurs that causes a wheel speed difference greater than 100 RPM, a flyweight mechanism opens to engage a latching bracket. The stopped flyweight triggers a self-energizing clutch system, forcing a cam plate to ramp against a side gear. Cam plate ramping will continue to increase until both axles turn at the same speed (full lock), which prevents further wheel slip. When the need for improved traction is gone - unlocking occurs automatically and the differential resumes normal operation.
I watched this video again. It came out over 10 years ago.
It doesn't provide any help understanding what they are referring to as "light-bias LSD".
Does anybody know exactly what a "light-biased LSD" is? I've never heard of it.
The rest of the paragraph says (in a nutshell) that it locks up when wheel speed difference is greater than 100 rpm. There is no partial lockup.
When I had the G80 gov-lock in my Sonoma with the 4.3 liter v6 it locked up the rear very quick. I remember leaving more than a few black marks in the road with that truck.
I just don't see where it functions as a LSD aside from the slipping and grabbing of the clutch packs used for locking it up?
It doesn't provide any help understanding what they are referring to as "light-bias LSD".
Does anybody know exactly what a "light-biased LSD" is? I've never heard of it.
The rest of the paragraph says (in a nutshell) that it locks up when wheel speed difference is greater than 100 rpm. There is no partial lockup.
When I had the G80 gov-lock in my Sonoma with the 4.3 liter v6 it locked up the rear very quick. I remember leaving more than a few black marks in the road with that truck.
I just don't see where it functions as a LSD aside from the slipping and grabbing of the clutch packs used for locking it up?
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asand
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G80 "locker" uses clutches. If you want smooth action use the additive, If you want maximum clutch life and maximum traction don't use it. In drag racing I've seen a stubborn guy repeatedly smoke the clutches in his 12 bolt Chevelle using the additive. After he was convinced to leave it out on the last rebuild he had no more issues.
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swathdiver
Full Access Member
Interesting, we used the factory additive in our 1980s Buicks and none of us ever had to rebuild our differentials until RWHP exceeded 550. We laid down miles and miles of twin stripes of black too! If I remember right, 2 or 2 1/2 of those little bottles did the trick and no chatter. Our G80s were 8.5" 10-Bolts and did not have the locking feature, just limited slip.
