Differential Oil, what kind?

[Kirwin]

Oil posts

As you can see red-rider, oil selection is always a hot topic. These guys mean the best; but the TDR is open to most anyone and everyone has an opinion about oil! Just be sure what ever you use meets the minimum specification that Dodge requires or realize that you, to quote our famous leader, "become your own warranty station". All IMHO. Ken Irwin

 

[amsoilman]

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

Well said, Hohn!



Wayne

amsoilman

 

[BHolm]

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.

Why? MARKETING Do you think the manufacturters actually PAY for that oil? What I do know for a fact about M1 is that my particular Porsche (928) model has seen multiple engine failures, I can think of 6-7 off the top of my head, on the racetrack running M1. I also know that none have failed running Amsoil, including one competing in the professional Speed GT series for the last three years.



I have owned several vehicles that came with M1 as the factory fill. It never stayed in there very long! Just my personal preference though. As already mentioned, the oil subject gets pretty crazy.

 

[LightmanE300]

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.

Thanks mberry - some people's rudeness is amazing. It sure would be nice if people would back up their claims with facts or explanations rather than simply trying to discredit someone's statements in an immature fashion. Mobil 1 is a high quality group 4 synthetic - if bholm or whoever thinks it's the bottom of the barrel they are simply uninformed.



Hohn - glad you think it's foolishness. What I think is foolishness is your advice to find an oil and then keep adding friction modifier until the noise is gone. Talk about a waste of time. I don't care if it has clutch packs, or what it is like inside the diff cover - I don't really know. All I do know is that I ran the Amsoil gear lube, and the diff made all kinds of noise when I went around corners. Several other folks have reported this, and reported the noise going away when switching to other brands. I frankly don't care to spend my time monkeying with it. I threw in the m1 and have no more noise.

 

[BHolm]

Rudeness??? Well now, if that isn't the pot calling the kettle black I don't know what is. You sir have the most snide attitude I have seen on this forum bar none. Someone else called you on it the other day and you claimed they were the only person to suggest you are rude in over 900 posts. Well, they are not alone.



Some facts for you... . in independant tests M1 fails miserably in the four ball wear test. It shows more wear than even conventional oils. My personal investigations revealed engine failures on cars running M1 where cars running Amsoil or Redline have not had failures. Coincidence... possible but the 6 to 0 kill ratio attributed to the M1 doesn't bode well.



I would also seriously question if M1 is all synthetic base stock. Mobil sued Castrol because they were claiming their oil as fully synthetic even though it did not use 100% synthetic base stocks. Somehow a judge ruled that Castrol could call their oil fully synthetic, even though it admittedly was not. Within a month or so of losing that suit M1 changed its formulation from the old tri-syn to the new super-syn. I would bet anything it is no longer a 100% synthetic base stock, a money making move for them, backed up by a judges ruling. Better yet, they do not have to admit what they really use.



As for information without any back-up... . you stated that Amsoil buys base stocks from Mobil, can you back that up?

 

[jsimpson]

Mobil and Amsoil use different base stocks. Unlikely that one buys from the other. I've been using synthetics since the first issuance of Amsoil and was an Amsoil dealer for over twenty years. I use Mobil1 now due to price and availability. I've found that despite claims to the contrary, frequent oil changes are STILL the best policy and I can change more frequently with Mobil1 than with Amsoil. I have had excellent results with Amsoil and with Mobil1. I use them in motorhomes, trucks, cars, lawnmowers, generators, motorcycles, lawn equipment, outboard motors, Hunter ceiling fans, and oil cans. I use drained synthetic for bar oil on my chain saw. I haven't used anyhting but synthetic foe longer than some of you have lived. I used Amsoil exclusively in my race car. Hohn, opinions are like anal orifices - everyone has one.

 

[amsoilman]

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.

Taken Directly from my 03' Service Manual.



DESCRIPTION - AXLE

NOTE: DaimlerChrysler recommends using Mopar

lubricants or lubricants of equal quality.

REAR AXLE

9 1/4 - Mopar Synthetic Gear Lubricant 75W-140

10 1/2 AA - Mopar Synthetic Gear Lubricant 75W-90

11 1/2 AA - Mopar Synthetic Gear Lubricant 75W-90



NOTE: Trac-Lok differentials require Limited Slip Additive in the lubricant. Trac-Rite™ differentials DO NOT require Limited Slip Additive.



The 3/4 and 1 ton trucks with Diesel use the 11 1/2 AA Axles in the rear. The Trac-Lok Differential is in the 9 1/4- Axles, which are installed in the 1/2 ton trucks.





Wayne

amsoilman

 

[rbattelle]

The Trac-Lok Differential is in the 9 1/4- Axles, which are installed in the 1/2 ton trucks.

Wayne

amsoilman

I don't mean to nitpick, but the 10. 5" axle also uses the Trac-loc differential and requires an additive.



Someone correct me if I'm wrong... I don't have my service manuals in front of me...



-Ryan

 

[Gauthier]

Mobil sued Castrol over the use of the word synthetic years before the super-syn formulation.



Here are a few facts:



1. ) ExxonMobil produces more synthetic basestock than any other company in the world.

2. ) Amsoil and Redline combined manufacture not one milliliter of synthetic oil. These two companies and many, many others blend additives with basestock purchase from other companies. I know for a fact that Amsoil has bought a large quanity of basestock from Mobil. I would bet Amsoil still purchase the majority of the basestock they use from ExxonMobil.

3. ) Most Mobil M1 oils are of excellent quality; none are "junk".

4. ) Most Amsoil oils are of excellent quality; none are "junk".



For 99. 999999% of the users on this forum, any oil meeting the required specifications will provide good service.

 

[LightmanE300]

Rudeness??? Well now, if that isn't the pot calling the kettle black I don't know what is. You sir have the most snide attitude I have seen on this forum bar none. Someone else called you on it the other day and you claimed they were the only person to suggest you are rude in over 900 posts. Well, they are not alone.



Some facts for you... . in independant tests M1 fails miserably in the four ball wear test. It shows more wear than even conventional oils. My personal investigations revealed engine failures on cars running M1 where cars running Amsoil or Redline have not had failures. Coincidence... possible but the 6 to 0 kill ratio attributed to the M1 doesn't bode well.



I would also seriously question if M1 is all synthetic base stock. Mobil sued Castrol because they were claiming their oil as fully synthetic even though it did not use 100% synthetic base stocks. Somehow a judge ruled that Castrol could call their oil fully synthetic, even though it admittedly was not. Within a month or so of losing that suit M1 changed its formulation from the old tri-syn to the new super-syn. I would bet anything it is no longer a 100% synthetic base stock, a money making move for them, backed up by a judges ruling. Better yet, they do not have to admit what they really use.



As for information without any back-up... . you stated that Amsoil buys base stocks from Mobil, can you back that up?

The 'gentleman' that called me rude the other day was just upset because I posted factual information that was contrary to his postings, on two different threads. If you want to jump on the bandwagon and call me snide or whatever, that's your loss. Sorry your panties are in a bunch and you decided to make a personal attack.



If you're so stuck on FACTS, lets see some FACTS that show that a 4 ball wear test is actually relevant to how oil performs in an engine, other than from an AMSOIL source? Amsoil loves to use that test and claims independent testing. I don't care what a four ball wear test says when my oil analysis of Mobil Delvac 1 is superb. You also are making a blanket statement about m1 - as if they are all identical and they all perform the same in tests - which is also inaccurate.



Mobil 1 is in fact a group 4 synthetic base oil. This is widely accepted in the industry, and while they will not tell you their exact 'proprietary' blends/additives or whatever, one can get a pretty solid idea of what's in the oil from the MSDS that all manufacturers put out. Yes, sadly castrol won their lawsuit and all wannabe synthetics like premium blue extreme, syntec, rotella synthetic, etc can now be called 'synthetics' despite having a partially petroleum base.



As for mobil supplying amsoil's base stocks - the tech at amsoil told me that. Also a friend that works for lubrizol (here in cleveland) told me they just make amsoil's additive package, and on a side note -that it's fantastic. I had no reason not to believe them. As G said in the post above - most of these oil companies are sourcing the base oils from ExxonMobil.

 

[red-rider]

DAM guys, cant we all just be friends with differences?



Alright I heard alot of feedback regarding Mobil 1 and Amsoil. To me I think there both great. Im asking about Valvoline Synpower 75w-90 full synthetic and it also has the GL-5 rating, BUT, it also have the modifier in it. See guys I dont want to be driving all around town looking for an oil. I'm looking for something that basically not hard to find. Would this valvoline synpower with the modifier GL-5, do damage instead of good on my differential? I mean I can get the mopar 75W-90 from the dealer but I sure dont want to pay no $30. 00 per quart. So Im asking will Valvoline do damage instead of good?

 

[txhawg]

My rear used to chatter all the time. It became annoying to my wife, who complained that it smelled bad too. I used an over the counter friction modifier, and the chattering increased for a day or two, then went away for a day or two, then came back on a regular basis. So, I went to see a specialist about it. I took his reccomendation, cut the beans out of my diet, and all is quiet again. :-laf :-laf :-laf :-laf

 

[rbattelle]

Im asking about Valvoline Synpower 75w-90 full synthetic and it also has the GL-5 rating, BUT, it also have the modifier in it. See guys I dont want to be driving all around town looking for an oil. I'm looking for something that basically not hard to find. Would this valvoline synpower with the modifier GL-5, do damage instead of good on my differential? So Im asking will Valvoline do damage instead of good?

I have changed mine out twice now (15000 and 30000) and both times I used Valvoline Synpower 75W-90. I have NO abnormal rear end noise... not a lick of trouble with either axle. I have 38000 now. I buy it in case quantities from a local distributor, but Napa has loads of it too (you'll need a full 7 quarts minimum to do both axles, plus any overfill allowed by aftermarket diff covers).



-Ryan

 

[Hohn]

Hohn - glad you think it's foolishness. What I think is foolishness is your advice to find an oil and then keep adding friction modifier until the noise is gone. Talk about a waste of time. I don't care if it has clutch packs, or what it is like inside the diff cover - I don't really know. All I do know is that I ran the Amsoil gear lube, and the diff made all kinds of noise when I went around corners. Several other folks have reported this, and reported the noise going away when switching to other brands. I frankly don't care to spend my time monkeying with it. I threw in the m1 and have no more noise.

LM300--

I wasn't trying to barb anyone. I was simply saying that:

1) Differential noise and oil quality are not related, as some think.
2) It's hard to find oil without the modifier in it already.

It's YOUR time and you're free to do as you wish. If your time is so precious that you don't want to be methodical in your lube selection, that's your prerogative. As for not caring whether or not the diff has clutches, then why care about knowing what your truck requires at all? Heck, just put ATF in every fillable port and call it good.

I think you DO care about what your truck has. You just want to make things unnecessarily complex. M1 off the shelf works and works fine, so why make more of it than necessary, right? I don't think you're cavalier about truck maintenance, as your post implied.

I agree with you that M1 products are far from junk, and those kinds of statement really harm the credibility of the poster, imho.

My limited experience with Amsoil has all been good. My experience with Redline has been as good or better, plus I don't have to deal with the "cult"-- I just order it online and wait.

JMHO, as always.

 

[red-rider]

Thanks Ryan,

I just picked up my 9 quarts, thanks to NAPA.

 

[rbattelle]

More Info

These guys say Valvoline is junk.



Mixed opinions about Valvoline and other brands.



Just wanted you to have another opinion of Valvoline besides my limited experience with it. I will probably continue to use it, as I've experienced nothing "bad" from it.



Seems like A LOT of people over there really like Mobil 1!!



-Ryan

 

[Kirwin]

10.5" AAM rear axles

rbattelle, acording to my 03 service manual (page 3-118) the AAM 10. 5 rear axles uses a Trac-Rite limited slip assembly. Therefore no snake oil required or desired by Dodge. Acording to the service manual all three AAM differentials use 75W-90 Mopar Synthetic Gear Lubricant (reference 03 service manual page 0-4).

 

[rbattelle]

rbattelle, acording to my 03 service manual (page 3-118) the AAM 10. 5 rear axles uses a Trac-Rite limited slip assembly. Therefore no snake oil required or desired by Dodge. Acording to the service manual all three AAM differentials use 75W-90 Mopar Synthetic Gear Lubricant (reference 03 service manual page 0-4).

You and Wayne are absolutely correct and I was wrong. I apologize for that... both the 10. 5 and 11. 5 are Trac-Rite systems.



-Ryan

 

[Bertram65]

Why? MARKETING Do you think the manufacturters actually PAY for that oil? What I do know for a fact about M1 is that my particular Porsche (928) model has seen multiple engine failures, I can think of 6-7 off the top of my head, on the racetrack running M1. I also know that none have failed running Amsoil, including one competing in the professional Speed GT series for the last three years.



I have owned several vehicles that came with M1 as the factory fill. It never stayed in there very long! Just my personal preference though. As already mentioned, the oil subject gets pretty crazy.

I never said it was any better than another oil, I question calling it bottom of the barrell. I think it is good oil, probably as good as any other synthetic out there.

 

[Bertram65]

Taken Directly from my 03' Service Manual.



DESCRIPTION - AXLE

NOTE: DaimlerChrysler recommends using Mopar

lubricants or lubricants of equal quality.

REAR AXLE

9 1/4 - Mopar Synthetic Gear Lubricant 75W-140

10 1/2 AA - Mopar Synthetic Gear Lubricant 75W-90

11 1/2 AA - Mopar Synthetic Gear Lubricant 75W-90



NOTE: Trac-Lok differentials require Limited Slip Additive in the lubricant. Trac-Rite™ differentials DO NOT require Limited Slip Additive.



The 3/4 and 1 ton trucks with Diesel use the 11 1/2 AA Axles in the rear. The Trac-Lok Differential is in the 9 1/4- Axles, which are installed in the 1/2 ton trucks.





Wayne

amsoilman

That is really relivent to the TDR and the trucks are are talking about, I did no realize I had to exclude the 1/2 tons, I figured we were all talking about 3/4 and 1 tons here. My mistake.