Differential Oil, what kind?

[red-rider]

Im a new member to the diesel world, I had a 1500 dodge magnum v8, 360 regular gasser. I have a general question.



I just got my mag hytec rear differential cover. I am planning on installing it this weekend but need help on which oil to use. The owners manual states 75w-90, I called the dealer and they stated 75w-140. I tow a 27 foot trailor, once or twice per month, and I plan on chaning the differential oil every 7,000 miles, due to towing.



I need help on which oil to use. I have the 48re, 11. 50 limited slip differential also. Please advise. Im also planning on using synthetic. Im just debating whether to use 75w-90 or 75w-140. Any advise is helpful.



Thanks

 

[El Putzo]

I'm kind of in the same boat as you. I have about 4000 miles on my new baby and will be changing the dif fluids soon just to get out any shavings or dirt that may be in there due to break in. I had the same question and have come to this conclusion: 7000 mile intervals would be overkill IMO unless you are towing extremely heavy and often. I was thinking more like every 25k for mine. I tow a 4500 lb (empty) gooseneck trailer loaded anywhere from empty up to 10k of cargo, several times per month. Now as for fluid, I have been told that any quality synthetic 75w90 will work fine. Or 75w140 if you tow heavy and often. You make the call. Personally I'm going with Redline 75w90NS in my difs, Redline MTL in the NV5600 and Redline C+ATF in the transfer case. JMO

 

[Bertram65]

I would stick with a high quality full synthetic 75w90 like Mobil 1 or Redline. I have never seen any documentation listing 75w140 as the reconmended oil for the AAM axles, I would stick to what is the documented reconmended oil. I think the 75w140 reconmendation is left over from the Dana axle days.

 

[BHolm]

I am a fan of Amsoil products, so that is what goes in my trucks. In my work trucks that tow 15k loads on a daily basis I run 75-140 in the rear diffs and 75-90 in the front (all of mine are 4wd). In my '05 , which is my personal truck, and will only see a really heavy load a couple times a year I am going to run the Amsoil Extreme Pressure 75-90 front and rear. The 75-90 is what the owners manual reccomends and should be fine in your application. I only went up to the 140 because of the severe use those trucks see.



I also think that a 7k change interval is a big waste of money, especially with the greatly increased capacity with the Mag-Tech cover. With the Amsoil I change the fluid in the work trucks every 50k miles. On my '99 Ford, using the same fluid and interval, again under severe service, I managed 200k miles before I went through the rear end and did a rebuild. I thought that was pretty decent considering that truck spends its life hooked to a big gooseneck or a snowplow.

 

[Bertram65]

I ran Amsoil in mine for one service interval, 15K miles, never had a problem. Is the Severe Gear something new? I ran the 2000 series in mine.

A number of people have reported on the TDR having noise from the rear with the Amsoil gear oil.

 

[amsoilman]

I ran Amsoil in mine for one service interval, 15K miles, never had a problem. Is the Severe Gear something new? I ran the 2000 series in mine.

A number of people have reported on the TDR having noise from the rear with the Amsoil gear oil.

TAKEN FROM THE AMSOIL INC> WEB SITE



AMSOIL Severe Gear Synthetic Extreme Pressure (EP) Lubricants are premium grade lubricants specifically engineered for maximum performance in severe duty applications. These state-of-the-art AMSOIL formulations feature an exclusive blend of high viscosity, shear stable synthetic base oils and an extra treatment of high-performance additives. AMSOIL Severe Gear Synthetic EP Lubricants maintain their viscosity for long-lasting protection against metal-to-metal contact. The proprietary AMSOIL additives form an iron-sulfide barrier coating on gear surfaces, providing the ultimate line of defense against wear, pitting and scoring. AMSOIL Severe Gear lubricants prevent "thermal runaway" - a phenomenon caused by a lubricant's inability to control friction and increased heat under high-stress conditions. By preventing thermal runaway, AMSOIL Severe Gear Synthetic EP Lubricants inhibit rapid lubricant degradation and component damage. Equipment runs better and lasts longer with AMSOIL Severe Gear Synthetic EP Lubricants.



Use in differentials, manual transmissions or other gear applications where one or more of the following standards are specified: API GL-5 & MT-1, MIL-PRF-2105E, Dana SHAES 234 (Formerly Eaton PS-037) for 250,000 miles, Mack GO-J, Arvin/Meritor 0-76N (75W-90) & 0-76M (75W-140), plus hypoid gear oil specifications from all foreign and domestic manufacturers such as GM, Ford and Daimler Chrysler. Can also be used in rear axles where API Service GL-4 lubricant is recommended.



Wayne

amsoilman

 

[BHolm]

I haven't heard any noise after the switch. The dually though needed a dose of limited slip additive to cure a little chatter from the rear on turns. The QC is also an 11. 5 but srw and lsd, no chatter on that one.

 

[OCarney]

I used Lucas full synthetic 75w90 at 15k, at 28k now, no noise or problems. I pull RV's & goosenecks, so I am loaded most of the time. The Lucas was around 9 bucks a qt.

 

[red-rider]

Hey Guys thanks for the response. I screwed up, I just checked my window sticker when I purchased my truck and I guess I have an Anti-Spin Differential not the limited slip , I guess there both different. I also read a few posts here that I dont need any additives when I change the oil if I had either, is this true? Although I do have another question.



Valvoline synthetic 75w-90 is this a good oil to use? I used to use this in my past trucks and I didnt really have any problems with it, but this is my first diesel, So, would this oil be sufficient for my truck?



Again Thanks.

 

[jsimpson]

I cured the limited slip dif chatter in my Vette with Amsoil 2000 gear oil and no additive. It chattered with up to four packs of additive before the switch.

 

[Bertram65]

The anti spin option in the 11. 5" rear is a gear controlled limited slip there are no clutchs that would require a friction modifier.

 

[Kirwin]

Owners manual recommendations

In your owners manual it tells you what to use. Your truck has a American Axle Manufactured rear axle (front too if its a 4X4). It uses a full synthetic 75-90 oil. Bertram65 has it correct, the limited slip Danas on the 02 and earlier used a friction modifier commonly called "snake oil". The 03 and laters do not use the 75-140 period. I recommend changing it at the 15K interval lisrted in the owners manual. Do a search for my thread on this topic "I changed my rear differentil oil and... " Hope this helps. Ken Irwin

 

[LightmanE300]

IMO the amsoil series 2000 75w90 is junk with a capital J. It definitely chattered in mine, and you shouldn't have to use limited slip additives in an axle that doesn't require it just to stop noises. I switched to the mobil 1 75w90 and the noise was instantly gone. Several people have reported this - enough to not bother trying the Amsoil IMO.

 

[BHolm]

OK Lightman, you go ahead and use Mobil 1 the most reviled synthetics(maybe synthetic anyway) on the planet, talk about bottom of the barrel

 

[Bertram65]

Not to start oil war, but, if Mobil 1 is junk why do some of the most expensive cars with some of the highest horsepower motors come with it as the factory fill and reconmened oil? No other oil that I know of is reconmended by brand, like Mobil 1 is.

 

[Hohn]

Hold on here, fellas.

First, a 'vette is not a CTD! Irrelevant until they make a 'vette with a Dana 70 or 80, or an AAM rear end.

Second, a gear-based anti-spin diff makes a HUGE difference.

Third, it's FOOLISHNESS to evaluate a gear lube based on whether or not it chatters in a clutch-type LSD. There are so many variations in diff setup that some may require NO additive at all, and others make require much more. Chatter resistance has NOTHING to do with the lubricational properties of the gear lube. I could take a cheapie GL-3 oil and make it not chatter, while a far superior synthetic GL-5 might chatter at first.

Fourth, many many gear oils are now coming with the diff modifier already in them-- both dino AND synthetic oils. In fact, EVERY valvoline gear oil sold in a 1-qt bottle already has modifier in it. The only way to NOT get modifier is to buy it in 5-gal pails.

Most M1 lubes also have the modifier already in it as well.

Look around and you'll see. It's VERY difficult to find a gear oil that doesn't already have modifier in it. You can either go really cheap (like I did) with the parts-store dino brand, or go nice with special modifier-free Redline NS series lubes and add the modifier yourself if you feel you need it.

Most people add way too much modifier because they add it until the chatter goes away. You SHOULD add a little, drive it for a week to see if it still chatters, then add a little more. So on. It takes a while for the modifier to soak in and work, so if you add it until the chatter goes away instantly, then you've added too much and your LSD function will be poor.

Choose your gear lube based on what your axle need the way YOU use it. If you tow, a 75-140 is a good idea, no matter what axle you have. Synthetic will perform better. Brand selection is Pandora's box, so choose what YOU like. If you don't tow, choose a 75-90 or 80-90. Dino or syn is more a matter of personal preference, just make sure it's GL-5 rated. The syn WILL perform better, but you'll have to do your own cost/benefit analysis.

jlh

 

[rbattelle]

I like Valvoline Synpower 75-90. But I'll echo Hohn's comments... any high-quality fully-synthetic GL-5 rated oil will do nicely.



For those who say their clutches chatter with certain types of oil, how is it that you have clutch chatter when there are no clutches in the 11. 5" LS unit (I'm not picking on you, Lightman... lots of people report some kind of chatter problem with certain oils)? I don't think the pinion brake shoes would chatter. Am I wrong? What is it you're hearing?



-Ryan

 

[Bertram65]

We are talking about 3rd gen trucks with AAM differentials, they require full synthetic 75w90 oil without any friction modifier, they are a gear based anti-spin, not clutchs. True most gear oils come with the FM built in now, but there is no need to add additional FM on the 3rd gen trucks.

I was talking about the Mobil 1 series oil as a whole, not the specific gear oil or engine oil.

 

[mberry]

OK Lightman, you go ahead and use Mobil 1 the most reviled synthetics(maybe synthetic anyway) on the planet, talk about bottom of the barrel

Please lets not bash or flame each other for our opinions.



I use Royal Purple 75-140 in the rear and 75-90 in the front. I think it's a great synthetic oil. I also think 15K change interval is about right given your description red rider.

 

[klenger]

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