75w90
- Thread starter LocoEngr
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Use the GM grape juice. OR Redline. Amsoil doesn't meet the GM spec AFAIK.
They should have it on GM parts direct. I think the number is 88900401
Get the part number form your dealer and then look on GM Parts direct.com
They should have it on GM parts direct. I think the number is 88900401
Get the part number form your dealer and then look on GM Parts direct.com
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GM grape juice is a good idea.
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Amsoil looks good to me for GM based on their website saying:
Recommended for use in differentials, manual transmissions and other gear applications requiring any of the following specifications: API GL-5, MT-1, MIL-PRF-2105E, Dana SHAES 234 (Formerly Eaton PS-037), Mack GO-J, or the differential (hypoid) gear oil specifications from all domestic and foreign manufacturers such as GM, Ford and Daimler Chrysler. Can also be used in axles where an API GL-4 lubricant is recommended.
No mention of 'AFAIK' on Redlines site? Just saying....no idea what AFAIK is, but I'm sure it's very important to someone.
http://www.redlineoil.com/product.aspx?pid=133&pcid=4
They are pretty specific on their recommendations. Case in point, they re-formulated their power steering fluid and now it's no longer compatible with Honda/Acura.
Recommended for use in differentials, manual transmissions and other gear applications requiring any of the following specifications: API GL-5, MT-1, MIL-PRF-2105E, Dana SHAES 234 (Formerly Eaton PS-037), Mack GO-J, or the differential (hypoid) gear oil specifications from all domestic and foreign manufacturers such as GM, Ford and Daimler Chrysler. Can also be used in axles where an API GL-4 lubricant is recommended.
No mention of 'AFAIK' on Redlines site? Just saying....no idea what AFAIK is, but I'm sure it's very important to someone.
http://www.redlineoil.com/product.aspx?pid=133&pcid=4
They are pretty specific on their recommendations. Case in point, they re-formulated their power steering fluid and now it's no longer compatible with Honda/Acura.
AFAIK = As far as I know.
dnewton3
Staff member
GM's fluid spec you refer to is #9986115; that is a requirement for syn 75w-90 with FM added and nothing more, despite what silliness you'll read elsewhere. Do NOT misunderstand that; it does NOT require that you run that grade or base stock. That spec number is what what defines the replacement fluid, but it does not require that the diff use that fluid. Also, that spec (#9986115) is what GM created for an over-the-counter (OTC) parts counter bottle. It simply directs any entity to provide the GL-5, in syn, with FM for immediate consumption by the purchaser to use for service or top-off fills. It's that simple; don't over-think it.
The only thing you need is a GL-5 with FM. If it comes with FM, then you need not add any. If it does not, you'll need some to reduce chatter and nuisance locking (if G80 equipped).
If the grape juice (GM fluid) got you this 100k miles, then just about any other GL-5 will get you another 100k ... It's just not that picky.
The diff is made by Eaton; here is what one of their engineers had to say some time back:
Automatic Locking Differential Lubricants. [Note from Michael Asmussen, Torque Control Products Division of Eaton Corp.] We recommend the following lubrications for our locking differentials:
1)Texaco 2276; Synthetic 75 W90; Gm Part # 9986115
2)Texaco 9622; Mineral based 80W90; GM Part # 9985290
3)Texaco 2080; Synthetic 75W140 (heavy duty applications); GM part # 9985991
Note - All of the above lubes are preblended with friction modifier. No additional modifiers are necessary or recommended. As far as other lubes are concerned, any standard GL 5 lube will work, but the units perform optimally with the three listed above.
Here is what Amsoil has contributed:
http://www.amsoil.com/techservicesbullet...%20revision.pdf
As you can see, the maker of the diff (made by Eaton, purchased by AAM for their axles) simply states that any GL-5 will work; syn or dino does not matter. Add FM if it is not included in the OTC product you purchase.
You can use Amsoil or RL, but they are really more expensive that what you need to use. If you are going to run another 100k miles, then I'd agree syn's might be a good choice. But they are not a requirement. Other options would be Mobil 1, Synpower, etc ...
The only thing you need is a GL-5 with FM. If it comes with FM, then you need not add any. If it does not, you'll need some to reduce chatter and nuisance locking (if G80 equipped).
If the grape juice (GM fluid) got you this 100k miles, then just about any other GL-5 will get you another 100k ... It's just not that picky.
The diff is made by Eaton; here is what one of their engineers had to say some time back:
Automatic Locking Differential Lubricants. [Note from Michael Asmussen, Torque Control Products Division of Eaton Corp.] We recommend the following lubrications for our locking differentials:
1)Texaco 2276; Synthetic 75 W90; Gm Part # 9986115
2)Texaco 9622; Mineral based 80W90; GM Part # 9985290
3)Texaco 2080; Synthetic 75W140 (heavy duty applications); GM part # 9985991
Note - All of the above lubes are preblended with friction modifier. No additional modifiers are necessary or recommended. As far as other lubes are concerned, any standard GL 5 lube will work, but the units perform optimally with the three listed above.
Here is what Amsoil has contributed:
http://www.amsoil.com/techservicesbullet...%20revision.pdf
As you can see, the maker of the diff (made by Eaton, purchased by AAM for their axles) simply states that any GL-5 will work; syn or dino does not matter. Add FM if it is not included in the OTC product you purchase.
You can use Amsoil or RL, but they are really more expensive that what you need to use. If you are going to run another 100k miles, then I'd agree syn's might be a good choice. But they are not a requirement. Other options would be Mobil 1, Synpower, etc ...
Originally Posted By: LocoEngr
2007 GMC Sierra Classic almost has 100,000 miles on it. Im getting ready to do the 100,000 mile maintenace on it.
Im thinking either Amsoil, or Redline for the gear oil. Is one really better than the other?
Thanks!
I hope this isn't the first diff service at 100K?
Either of those will do the job. Both are good. I had a couple Silverado's( 05 and 07 NBS )and I ran RP MaxGear 75W90 front and rear and it worked great. I highly recommend RP if you are willing to use it.
Don't waste your time with the GM Grape Juice. Nothing special and very expensive.
2007 GMC Sierra Classic almost has 100,000 miles on it. Im getting ready to do the 100,000 mile maintenace on it.
Im thinking either Amsoil, or Redline for the gear oil. Is one really better than the other?
Thanks!
I hope this isn't the first diff service at 100K?
Either of those will do the job. Both are good. I had a couple Silverado's( 05 and 07 NBS )and I ran RP MaxGear 75W90 front and rear and it worked great. I highly recommend RP if you are willing to use it.
Don't waste your time with the GM Grape Juice. Nothing special and very expensive.
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Mobil 1 75w90 on my 2013
^ditto on my '01 Tundra, although I have used Redline before also and loved it. Can't go wrong with Amsoil either.
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Originally Posted by jjbaer12
It's not what they're saying now....if you have a locking differential you DO NOT use a gear lube that has any limited slip type additives. Doing so could cause it to not lock up....
Thats why factory always says...in case if it doesnt want to lock up.....try to steer your car left&right while driving for a few meter....
It's not what they're saying now....if you have a locking differential you DO NOT use a gear lube that has any limited slip type additives. Doing so could cause it to not lock up....
Thats why factory always says...in case if it doesnt want to lock up.....try to steer your car left&right while driving for a few meter....
MolaKule
Staff member
Originally Posted by jjbaer12
It's not what they're saying now....if you have a locking differential you DO NOT use a gear lube that has any limited slip type additives. Doing so could cause it to not lock up....
Who is saying what? Please name your source and quote them if you can with the " button, upper right.
There are many types of locking differentials so it is important to specify the type of differential and the specific fluid that is required.
For clutching type differentials what Dave said above still applies:
Originally Posted by DNEWTON3
GM's fluid spec you refer to is #9986115; that is a requirement for syn 75w-90 with FM added and nothing more, despite what silliness you'll read elsewhere. Do NOT misunderstand that; it does NOT require that you run that grade or base stock. That spec number is what what defines the replacement fluid, but it does not require that the diff use that fluid. Also, that spec (#9986115) is what GM created for an over-the-counter (OTC) parts counter bottle. It simply directs any entity to provide the GL-5, in syn, with FM for immediate consumption by the purchaser to use for service or top-off fills. It's that simple; don't over-think it.
The only thing you need is a GL-5 with FM. If it comes with FM, then you need not add any. If it does not, you'll need some to reduce chatter and nuisance locking (if G80 equipped).
If the grape juice (GM fluid) got you this 100k miles, then just about any other GL-5 will get you another 100k ... It's just not that picky.
The diff is made by Eaton; here is what one of their engineers had to say some time back:
Automatic Locking Differential Lubricants. [Note from Michael Asmussen, Torque Control Products Division of Eaton Corp.] We recommend the following lubrications for our locking differentials:
1)Texaco 2276; Synthetic 75 W90; Gm Part # 9986115
2)Texaco 9622; Mineral based 80W90; GM Part # 9985290
3)Texaco 2080; Synthetic 75W140 (heavy duty applications); GM part # 9985991
Note - All of the above lubes are preblended with friction modifier. No additional modifiers are necessary or recommended. As far as other lubes are concerned, any standard GL 5 lube will work, but the units perform optimally with the three listed above.
Here is what Amsoil has contributed:
http://www.amsoil.com/techservicesbullet... revision.pdf
As you can see, the maker of the diff (made by Eaton, purchased by AAM for their axles) simply states that any GL-5 will work; syn or dino does not matter. Add FM if it is not included in the OTC product you purchase.
You can use Amsoil or RL, but they are really more expensive that what you need to use. If you are going to run another 100k miles, then I'd agree syn's might be a good choice. But they are not a requirement. Other options would be Mobil 1, Synpower, etc ...
It's not what they're saying now....if you have a locking differential you DO NOT use a gear lube that has any limited slip type additives. Doing so could cause it to not lock up....
Who is saying what? Please name your source and quote them if you can with the " button, upper right.
There are many types of locking differentials so it is important to specify the type of differential and the specific fluid that is required.
For clutching type differentials what Dave said above still applies:
Originally Posted by DNEWTON3
GM's fluid spec you refer to is #9986115; that is a requirement for syn 75w-90 with FM added and nothing more, despite what silliness you'll read elsewhere. Do NOT misunderstand that; it does NOT require that you run that grade or base stock. That spec number is what what defines the replacement fluid, but it does not require that the diff use that fluid. Also, that spec (#9986115) is what GM created for an over-the-counter (OTC) parts counter bottle. It simply directs any entity to provide the GL-5, in syn, with FM for immediate consumption by the purchaser to use for service or top-off fills. It's that simple; don't over-think it.
The only thing you need is a GL-5 with FM. If it comes with FM, then you need not add any. If it does not, you'll need some to reduce chatter and nuisance locking (if G80 equipped).
If the grape juice (GM fluid) got you this 100k miles, then just about any other GL-5 will get you another 100k ... It's just not that picky.
The diff is made by Eaton; here is what one of their engineers had to say some time back:
Automatic Locking Differential Lubricants. [Note from Michael Asmussen, Torque Control Products Division of Eaton Corp.] We recommend the following lubrications for our locking differentials:
1)Texaco 2276; Synthetic 75 W90; Gm Part # 9986115
2)Texaco 9622; Mineral based 80W90; GM Part # 9985290
3)Texaco 2080; Synthetic 75W140 (heavy duty applications); GM part # 9985991
Note - All of the above lubes are preblended with friction modifier. No additional modifiers are necessary or recommended. As far as other lubes are concerned, any standard GL 5 lube will work, but the units perform optimally with the three listed above.
Here is what Amsoil has contributed:
http://www.amsoil.com/techservicesbullet... revision.pdf
As you can see, the maker of the diff (made by Eaton, purchased by AAM for their axles) simply states that any GL-5 will work; syn or dino does not matter. Add FM if it is not included in the OTC product you purchase.
You can use Amsoil or RL, but they are really more expensive that what you need to use. If you are going to run another 100k miles, then I'd agree syn's might be a good choice. But they are not a requirement. Other options would be Mobil 1, Synpower, etc ...
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May be too late for OP's purposes, but I recently purchased parts online from what appears to be a large a gear supply shop (which will remain unnamed) and a link attached to my invoice lead me to the following. I do not know their motivation for such statements so I just put it out here for the banter that may follow.
"
**** RECOMMENDS LUCAS DINO 85W140 & LUCAS 80W90 FOR EXTREME COLD
**** Gear Oil Recommendation - Why We Recommend Non-Synthetic Oil **** recommends Dino (Non-Synthetic) 85w140 Lucas oil with a Ford or Dana limited slip additive for clutch style posi's. The gear oil question is an age old debate that comes down to opinion. We base our opinion on differentials we have seen. Scientifically it has been proven that that when measuring diff temps, the actual "metal objects" stay cooler using a quality dino oil with an additive package over synthetic oils. However it has been proven that synthetic "oils" can stay cooler then dino oil. So it depends on what temperature you measure the "metal" or the "oil" hence why both can claim they are better.
Other findings and this varies based on the actual synthetic used. Synthetics thin out quickly once hot and lose their cling ratio to the metal object, when the oil is stuck to the gear it provides a cooling factor for the metal. We also believe that dino oil has better pressure properties, i.e. it provides a better cushion then synthetic for two reasons. First, it does not thin out as much and two it clings to the gear.
Another important attribute of differential oil is water separation. A gear oil that will hold its separation from water will protect the differential. It is in our experience that if you add water to a diff with Synthetic there is no clear delineation between the two. On a dino oil there is excellent water separation properties. Water will ruin diffs as it affects its pressure properties resulting in surface wear quickly, so any oil that keeps its separation properties will outperform one that will not.
An easy not so scientific test is to install synthetic and run your diff for 30 minutes, pop cover and watch how it comes out and feel it. Most we have seen are extremely thin and act almost like water. Same test with Lucas it runs slower and will be stuck to the gear.
All synthetics cost more money than Lucas dino oil, and I feel there is a risk in what you are getting with synthetic. I find it much wiser to run the lower cost oil and increase the frequency of change. No matter which oil used, the higher the heat in the diff, the faster oxidation occurs and the oil breaks downs. At 140 degrees if no trash or moisture is introduced oil will basically last a million miles. However for roughly every 20 degrees above 140 it cuts life expectancy in half. A well broke in diff under normal conditions will run around 200 degrees and a quality gear oil will last 100k using above formula. However it is not uncommon for differentials to see higher temps when worked hard (steep grades, towing, speed, shock loading, ect.) which is why manufacturers generally recommend 30k intervals normal service and 15k or less for severe service. A differential that is too small for the vehicle obviously sees more strain and thus builds more heat. So an undersized diff under normal conditions will run hotter and require more frequent changes. Other notes on heat: 300 degrees is too hot, 250-270 is normal for a new diff and gear oil should be changed at 500 miles.
In the end comparing gear oil is a useless debate that is tainted by advertisement and claims that aren't proven, it all comes down to heat and the oil breaking down. Instead of spending $100 dollars on synthetic, spend $20 on Lucas and install a $50 temp gage on your diff. If your diff regularly sees mileage over 200f change the oil frequently, if it doesn't save your money. The flip side to this is synthetic sellers say their oil stays cooler and lasts longer. I think it is false advertisement that can't be proven by the average purchaser. If you ran dino and the diff regularly ran above 200 it would be worth trying a high quality synthetic oil and proving their claims with a temp gauge.
Opinions on specific gear oils:
Royal Purple: In our opinion one of the worst gear oils made
Valvoline synthetic: Better than royal purple but dino out performs
Ford synthetic: Probably Valvoline not the worst but think dino is better
GM synthetic: Similar to ford Toyota synthetic: Average same performance as most dino's I think Lucas is better
Mobil 1 synthetic: Better than economy dino's and is likely comparable to Lucas or other quality dinos with additive packages
Amsoil severe duty: Better than all economy Dino's and all synthetics on the market, but marginal over a quality dino with additive package
Redline shockproof: Same as Amsoil
The only synthetic's I would consider are Amsoil, and redline, along with some industrial synthetic's that aren't really marketed to your everyday user. But would only consider if I was trying to control a heat problem, or shock load issue generally related to doing something the differential was never designed to do in the first place. In the end changing the oil more frequently will result in less wear and longer life in and will cost less money.
Conclusion Notes:
4 Most Important Attributes to Gear Oil
o Cling Ratio
o Water separation properties
o Cushioning Factor
o Temperature Control
Temp Reference Chart - oil change frequency
o 170 Deg - 100,000 Miles
o 200 Deg - 50,000 Miles
o 220 Deg - 25,000 Miles
o 240 Deg - 12,000 Miles
o 260 Deg - 5,000 Miles
o 260-300 Deg - 500-1000 Miles until Temp is controlled
Differential Temp Guide
o 250-275 Degrees is Normal for new differentials breaking in, do not Tow or take long road trips for first 500 miles as this builds additional heat. 300 degrees is to hot and diff should be allowed to cool.
o Normal operating Temp for a differential adequate for vehicle in stock applications 170-220 degrees
o Normal operating Temp - Large tires, Undersized Differentials, Towing 200-250 Degrees.
Final Notes
o Change your oil frequently your diff will thank you
o If water is ever introduced to differential change it immediately, keep in mind that a differential that is hot and then becomes cool will naturally draw in moisture, so it is not always a water crossing that causes moisture contamination, always run a vent to a dry area and insure it breathes easily.
"
"
**** RECOMMENDS LUCAS DINO 85W140 & LUCAS 80W90 FOR EXTREME COLD
**** Gear Oil Recommendation - Why We Recommend Non-Synthetic Oil **** recommends Dino (Non-Synthetic) 85w140 Lucas oil with a Ford or Dana limited slip additive for clutch style posi's. The gear oil question is an age old debate that comes down to opinion. We base our opinion on differentials we have seen. Scientifically it has been proven that that when measuring diff temps, the actual "metal objects" stay cooler using a quality dino oil with an additive package over synthetic oils. However it has been proven that synthetic "oils" can stay cooler then dino oil. So it depends on what temperature you measure the "metal" or the "oil" hence why both can claim they are better.
Other findings and this varies based on the actual synthetic used. Synthetics thin out quickly once hot and lose their cling ratio to the metal object, when the oil is stuck to the gear it provides a cooling factor for the metal. We also believe that dino oil has better pressure properties, i.e. it provides a better cushion then synthetic for two reasons. First, it does not thin out as much and two it clings to the gear.
Another important attribute of differential oil is water separation. A gear oil that will hold its separation from water will protect the differential. It is in our experience that if you add water to a diff with Synthetic there is no clear delineation between the two. On a dino oil there is excellent water separation properties. Water will ruin diffs as it affects its pressure properties resulting in surface wear quickly, so any oil that keeps its separation properties will outperform one that will not.
An easy not so scientific test is to install synthetic and run your diff for 30 minutes, pop cover and watch how it comes out and feel it. Most we have seen are extremely thin and act almost like water. Same test with Lucas it runs slower and will be stuck to the gear.
All synthetics cost more money than Lucas dino oil, and I feel there is a risk in what you are getting with synthetic. I find it much wiser to run the lower cost oil and increase the frequency of change. No matter which oil used, the higher the heat in the diff, the faster oxidation occurs and the oil breaks downs. At 140 degrees if no trash or moisture is introduced oil will basically last a million miles. However for roughly every 20 degrees above 140 it cuts life expectancy in half. A well broke in diff under normal conditions will run around 200 degrees and a quality gear oil will last 100k using above formula. However it is not uncommon for differentials to see higher temps when worked hard (steep grades, towing, speed, shock loading, ect.) which is why manufacturers generally recommend 30k intervals normal service and 15k or less for severe service. A differential that is too small for the vehicle obviously sees more strain and thus builds more heat. So an undersized diff under normal conditions will run hotter and require more frequent changes. Other notes on heat: 300 degrees is too hot, 250-270 is normal for a new diff and gear oil should be changed at 500 miles.
In the end comparing gear oil is a useless debate that is tainted by advertisement and claims that aren't proven, it all comes down to heat and the oil breaking down. Instead of spending $100 dollars on synthetic, spend $20 on Lucas and install a $50 temp gage on your diff. If your diff regularly sees mileage over 200f change the oil frequently, if it doesn't save your money. The flip side to this is synthetic sellers say their oil stays cooler and lasts longer. I think it is false advertisement that can't be proven by the average purchaser. If you ran dino and the diff regularly ran above 200 it would be worth trying a high quality synthetic oil and proving their claims with a temp gauge.
Opinions on specific gear oils:
Royal Purple: In our opinion one of the worst gear oils made
Valvoline synthetic: Better than royal purple but dino out performs
Ford synthetic: Probably Valvoline not the worst but think dino is better
GM synthetic: Similar to ford Toyota synthetic: Average same performance as most dino's I think Lucas is better
Mobil 1 synthetic: Better than economy dino's and is likely comparable to Lucas or other quality dinos with additive packages
Amsoil severe duty: Better than all economy Dino's and all synthetics on the market, but marginal over a quality dino with additive package
Redline shockproof: Same as Amsoil
The only synthetic's I would consider are Amsoil, and redline, along with some industrial synthetic's that aren't really marketed to your everyday user. But would only consider if I was trying to control a heat problem, or shock load issue generally related to doing something the differential was never designed to do in the first place. In the end changing the oil more frequently will result in less wear and longer life in and will cost less money.
Conclusion Notes:
4 Most Important Attributes to Gear Oil
o Cling Ratio
o Water separation properties
o Cushioning Factor
o Temperature Control
Temp Reference Chart - oil change frequency
o 170 Deg - 100,000 Miles
o 200 Deg - 50,000 Miles
o 220 Deg - 25,000 Miles
o 240 Deg - 12,000 Miles
o 260 Deg - 5,000 Miles
o 260-300 Deg - 500-1000 Miles until Temp is controlled
Differential Temp Guide
o 250-275 Degrees is Normal for new differentials breaking in, do not Tow or take long road trips for first 500 miles as this builds additional heat. 300 degrees is to hot and diff should be allowed to cool.
o Normal operating Temp for a differential adequate for vehicle in stock applications 170-220 degrees
o Normal operating Temp - Large tires, Undersized Differentials, Towing 200-250 Degrees.
Final Notes
o Change your oil frequently your diff will thank you
o If water is ever introduced to differential change it immediately, keep in mind that a differential that is hot and then becomes cool will naturally draw in moisture, so it is not always a water crossing that causes moisture contamination, always run a vent to a dry area and insure it breathes easily.
"
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