Jump to content

2011 Chevy Suburban 2500 HD - Differential Fluid

Justin Jia
 Share

Recommended Posts

Justin Jia Enthusiast

Justin Jia

Posted
Posted

Hi, folks,

 

I have a 2011 Chevy Suburban 2500 HD, 6.0L gas.  RPO contains G80, GT4, L96.  This is my 1st post on the forum, and hope I’m posting in the right place. 

 

Could someone please help me with the rear axle/differential fluid? Owners manual 
states SAE75W-90 Synthetic Axle lube (GM#89021677, replaced by 88900401). It DOESN’T say anything about Limited-Slip Axle lubricant additive (GM #1052358, replaced by 88900330).  

 

However, as shown in the attached picture, ACDelco states the car NEED FRICTION MODIFIER w/LOCKING/LIMITED SLIP DIFFERENTIALS-USE ADDITIVE 88900330; Quantity varies by application.

 

How do you think please? Thanks and Happy Thanks Giving!

529BE30E-4C2F-4214-8D76-BB01000588E3.png

davester Senior Enthusiast

davester

Posted
Posted

From several forums where there have been threads on this, most people find "plain" 75W90 works fine, some people, for whatever reason, find the G80 chatters with using plain, and adding a bit of friction modifier makes it go away.

 

GM claims the G80 doesn't need it, I believe some people have found Eaton (who makes the G80) does want the friction modifier (as it does have a clutch).

Z45 Senior Enthusiast

Z45

Posted
Posted

Its NOT a limited slip differential...

 

¨ Optional Equipment (G80 Order Code) on all GM two-wheel and four-wheel drive light trucks and sport utilities.

Benefits

¨ Improved traction differentiates the vehicle relative to other rear wheel and four-wheel drive vehicles on the market.

¨ Maintenance free; requires no lube additives.

¨ Enhanced towing and off-road performance.

¨ Patented carbon friction disc technology enhances performance and durability while reducing warranty claims.



Principles of Operation

¨ Wheel speed difference (left to right) in excess of 100 RPM will cause a flyweight mechanism to open and catch a latching bracket.

¨ The stopped flyweight will trigger a self-energizing clutch system, which results in the cam plate ramping against a side gear.

¨ Ramping increases until both axles turn at the same speed (full lock), which prevents further wheel slip.

¨ At speeds above 20MPH, the latching bracket swings away from the governor and prevents lockup from occurring.



Technical Specifications

¨ Automatic locking takes place within a fraction of a second, so smoothly that it is unnoticed by the average driver.

¨ Unlocking occurs automatically, once the need for improved traction is gone, and is unnoticeable to the average driver.

¨ Compatible with anti-lock brake systems.

Z45 Senior Enthusiast

Z45

Posted
Posted (edited)

from GM service info....

Quote

Condition/Concern:
Customers may comment on a chatter or shudder from the rear axle on vehicles equipped with an Eaton locking differential. This condition would be noticed in parking lot maneuvers, turning, or during locking differential engagement and may be more noticeable when the differential is hot. Locking differential clutch chatter may be causing this concern.

If differential clutch chatter is encountered in a vehicle equipped with an Eaton locking differential, flush, drain and refill the differential with new synthetic fluid. If the condition returns, replace the rear differential clutch plates and refill the differential with new synthetic fluid, use the fluid part number listed in SI for the vehicle currently being worked on.

Important: Installing any friction modifier causes the clutch pack in the locking differential to slip and miss engagement. A fluid flush can often remove debris that is a contributor to clutch chatter. Adding friction modifier additive can cause a loss of locking differential functionality.

 

 

Chatter is essentially the build-up and release of energy between the differential clutch packs in a limited slip differential during operation. This phenomenon often occurs when torque is transferred between the clutches or when rotational speeds change. During the stick-slip phase, energy is built up to a point where contact between the clutch plates change between static friction (stick) and dynamic friction (slip), resulting in noticeable vibrations. It is this vibration that causes an audible chatter or ratcheting to be heard within the differential. While certainly an annoying characteristic, there is typically no mechanical damage occurring to the differential. It is most often noticed in parking lots or slow driving while turning where the outside wheel turns faster than the inside wheel.

In an effort to control this chatter, friction modifiers are often used. These additives result in a smoother transition between the two states of friction: static and dynamic. Static friction occurs when the clutches physically lock together, while dynamic friction occurs as the clutches are slipping, ergo Limited Slip Differential.

 

Edited by elcamino
Justin Jia Enthusiast

Justin Jia

Posted
  • Author
Posted

Thank you Dave and Mike!

 

mike, I think this video shows how the Eaton G80 works.  Seems people still call it LSD. 
 

 

diyer2 Senior Enthusiast

diyer2

Posted
Posted

I have never used a friction modifier in a G80. Never had chatter. Changing it more often helps IMO.

It does not require a friction modifier.  

Justin Jia Enthusiast

Justin Jia

Posted
  • Author
Posted
7 minutes ago, diyer2 said:

I have never used a friction modifier in a G80. Never had chatter. Changing it more often helps IMO.

It does not require a friction modifier.  


I plan to do the same for now, unless there’ are issues, then it won’t be too late to add friction modifier. Thanks!

CamGTP Senior Enthusiast

CamGTP

Posted
Posted

Amsoil or Valvoline is what I use or tell people to use. It works great.

 

Lots of people like Redline oil as well but that seems to be harder to find at most auto parts store.

  • Like 1
jake111 Enthusiast

jake111

Posted
Posted

The GM "grapejuice" and the other major brands (I use Mobil 1 Synthetic Gear Lubricant LS 75W-90) already have the proper amount of friction modifiers for the G80.  Not enough, or too much, friction modifier will give you unsatisfactory results.  I can recommend the Mobil 1 since I've used it for 15 years (over 100k miles) now without any differential problems, or chatter, or other ill behavior or noise.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • diyer2
      Oil Consumption

      By diyer2 · Posted

      I have changed oil and filter for years by starting a cold engine to warm oil up, let it run 5-10 minutes depending on temperature. Drain until it starts dripping, refill with quantity from owners manual or get it close.   
    • Chuck FB
      Fluid Change Questions

      By Chuck FB · Posted

      I changed the factory fill oil in the rear diff of my truck for the first time today and the miles is close to 9000 on the truck. There was a lot of fines on the magnet, a very thick layer but working it through my fingers it all felt like mush and as most know it appears like graphite, so no surprise chunks anyway. Certainly was time to do it from my thinking and could have been done sooner but the oil didn't look awful but sure wasn't new looking and never expected it to either. I did use some solvent to help me clean out the bottom area of the axle housing, just get any other stuff settled at the bottom washed and wiped out of the housing for the bit of effort it takes. I used Amsoil Severe Gear 75W90 in the easy packs to try out what they are like and I used up 4 packs and didn't spill much at all in the process but did take all four of the packs and go to the work bench and emptied them into a measuring container and there certainly was some in them that added up to something, then poured that into one of the easy packs and squirted in what I could get out of it. I would say the level is within 1/8th of an inch of being level with the threads at the fill plug so just the perfect amount. Once again, more than what GM says the fill volume is but computes with what others are adding to their rear diffs as well. 
    • Chuck FB
      Oil Consumption

      By Chuck FB · Posted

      So speaking of oil consumption with my L8T as I just changed the oil yesterday and made the switch over to Amsoil SS 0W-40 from the Mobil 1  5W-30 Truck and SUV I just dropped out. 2900 miles on that oil as well as  68 hours on that oil ( so used to equipment with an hour meter and that becomes valuable information to compare with others as well ). Once again the oil use was so very little, I am going to say it dropped under 1/16 of an inch on the dipstick. No towing was done and this interval was from early spring until now.    One interesting item to note is that going by the 5 quart jugs I was using before from Mobil, it was showing that I was putting in 8 US quarts to bring it to full if not slightly over the full mark according to their jug markings. Granted I did allow more drain time this time and in part because the engine oil was only lukewarm as I started it and let it idle and not for long enough to get the oil itself hot ( the engine was up to operating temp ). The oil in that state just seemed to take forever for it to drip out but not only at the drain plug but at the oil filter housing as well, perhaps I had never quite gotten all the oil out before and I could have still waited longer but as it was I waited well over 3 hours. I think next time if I have the time I will do an experiment by dropping the oil and lets say leave the pan under it for 15 minutes, then switch to another pail and let it drip out overnight and measure how much more oil comes out. So this time and yes I ended up getting it just over the full mark as I was experimenting with trying to get the level to the add mark after I had run it and then waited some and then added a bit and waited for a certain amount of time for it to settle to the add mark. I very well may not have waited long enough for that experiment but I got to the add mark, then dumped in a full quart and waited some and checked and then waited some more and it crept up more ... and then finally oops, it was slightly over full some hours later when it really had settled all it would. I find this engine sure takes time for the last bit of oil that gets poured in to finally make its way into the crank case. I can only guess at how much too much I added as per maybe a 1/10th of a quart. I had poured in 8.5 quarts going by the quart containers as per 8 quarts and 16 us ounces. I was shocked at how much this was off compared to the prior oil changes and if those larger jugs and they are not marked accurately enough or they contain slightly more than what they say, or the drain time factor made that much of a difference. But I know on this forum there have been others who have said they have put well over 8 quarts in their L8T and now I have also going by the Amsoil true quart containers. Its a confusing convoluted mess up here in Canada with some oil manufactures packaging is in true US quarts, some is also in true US quarts containers on an even number of quarts but also marked in liters which becomes the odd ball volume of a fractional amount of liters. Then there is the Liters only containers, no US markings as its a true metric container and only measured in Liters to an even number of Liters. But remember we used to have Imperial Gallons and Imperial quarts as well !. 
    • Atlas
      2027 GMC Sierra: Official Discussion

      By Atlas · Posted

      Holy smokes. Clearly not a deal on that truck. I just mean in general, matte or painted trim is becoming more normative than chrome, but I know the Black Optics packages on various vehicles are being sold as uplevel trims. They look really good, but sheesh. It's just paint and plastic.
    • Grumpy Bear
      Some Assembly is Required

      By Grumpy Bear · Posted

      I Wouldn't Know Where to Begin    Oh I know where I would begin but I'm just one of over eight billion people on this rock. Eight billion versions of where the goal post is. How large it should be. How far to kick from. What ball is the right ball. Elevation. Age.....are you getting the point? It isn't about disagreeing with one individual. It's about agreeing only with one individual. One's self.   Agreement comes when multiple people hold the same point already. THAT is the goal of an education. Building the Social Contract. That thing that allows us to all read this sentence. We've agreed on the alphabet and how to arrange those letters into words we agree upon whose meanings hold true for everyone entering into that contract. Those words arranged into a sentence form an idea and several sentences strung together in a paragraph convey an argument for or against or inform the reader of a state, condition or perhaps reveal a things nature. Paint a word picture. Make oneself known.    This contract is not limited to words although they are often explained by words. Things like numbers and their usefulness. Physics, Chemistry, Medicine, Music, Art and so on.    The frequency of middle C (C4) is 261.63 Hz is a first principle. We build on that to make music we all can enjoy even if we all can not compose or play. You don't have to master it to make it enjoyable and useful.    So why is the Beginning so difficult? Why is agreement so elusive?   Everyone "Signs" the contract (when receiving that education in obtaining it)  but fewer and fewer in this world have any intention of living by that contract. They find exploiting that contract more advantageous. Disruption. With intent. Without intent. In Ignorance. In your face. With a double dog dare you. With a hold my beer. In resistance to that contract and in spite how it looks on us. It permeates the very air we breath.    In this way the contract is subject to advantage. Abide by it when it serves you, disregard it when it doesn't. Unpredictable and self-serving. Corrosive.....Toxic........   It says a lot about a persons character to disregard the contract, the truth, first principles. None of it good.        ********************************************************   https://medicine.yale.edu/news-article/character-vs-personality-who-we-are-and-who-we-aspire-to-be/   Just an interesting article.   

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...