differential additive

[jrgough]

I changed the fluids about 10,000 mile ago with mopar 75/90 and now have some funky popping when i cross a small swall or ditch. i did not add the additive beacause it said not should I? Will it hurt if I do? Should i go back with 75/140 gear oil? I do not see any leaks also.



i just check my window sticker from when I bought it and it said i have anti spin 11. 5 axles

 

[rbattelle]

Are you sure the popping is the differential and not a bad universal joint (or carrier bearing)?

There is no reason to add any additives to the rear end. Have you been using 75-140 all this time?

-Ryan

 

[Wingate]

I changed the fluids about 10,000 mile ago with mopar 75/90 and now have some funky popping when i cross a small swall or ditch. i did not add the additive beacause it said not should I? Will it hurt if I do? Should i go back with 75/140 gear oil? I do not see any leaks also.



i just check my window sticker from when I bought it and it said i have anti spin 11. 5 axles

did you buy synthetic oil? Not sure if it matters, but the factory fill is synthetic.

The 140 is what I run, but I live in East Texas... ... it gets HOT here. !!

 

[HBarlow]

As Wingate said, the AAM axle used in 2003 and newer Rams does not require an additive. The friction modifier additive was required in Gen II Dana axles.

Synthetic is the right stuff for your rear differential.

 

[jrgough]

I have 62,000 miles and have changed the fluid about 15,000 - 20,000 miles ago. this just started recently. I went back when I changed it with Mopar 75/90 from the dealership. i pulled the plug and the level is just below (1/4th inch) with very little fine grain shavings (normal wear) on the plug

 

[steved]

Regardless of the AAM requirement, some fluids need additive... I had to add 4oz of Mopar additive to my current fill to make it quit chattering under load (it feels like two blocks of rubber sliding past each other).

 

[Cosmo]

Nearly all synthetic gear lubes have limited slip friction modifiers included - the obvious exceptions being those which are marketed for transmissions and whatnot that don't work properly with the additives, such as Redline 75w90NS which I used in my Subaru's manual transmission. Gear oils with friction modifiers cause the syncros to not work properly.


Make sure you're using a good quality synthetic gear oil.

 

[BIGNASTY]

Regardless of the AAM requirement, some fluids need additive... I had to add 4oz of Mopar additive to my current fill to make it quit chattering under load (it feels like two blocks of rubber sliding past each other).

You dont have the description of your truck what year and model just for Info sake

 

[BIGNASTY]

When I changed mine I called the dealer (big mistake ) and asked them they said that would determine if it needed it or not when they did the service. I told them that they would not be doing it so they wouldnt give the info. I got the VIN and called Dodge and got the info. SO MUCH FOR DEALERSHIPS

 

[HBarlow]

Nearly all synthetic gear lubes have limited slip friction modifiers included - the obvious exceptions being those which are marketed for transmissions and whatnot that don't work properly with the additives, such as Redline 75w90NS which I used in my Subaru's manual transmission. Gear oils with friction modifiers cause the syncros to not work properly.

Make sure you're using a good quality synthetic gear oil.

Do you have a source that suggests that "nearly all synthetic lubes contain friction modifiers"? I don't believe that is correct.

 

[steved]

you dont have the description of your truck what year and model just for info sake

2004. 5... 11. 5aam.


The factory fill was fine, but it got dumped at 50k.

I ran Mobil 1 75w90 for a short from 50k to 75k, until it turned extremely dark and smelled burnt. I still have this oil in the front differential and it has stayed completely clear since installation (unlike the rear diff), but it doesn't see much use with the DT kit either.

I ran 75w90 Royal Purple for a short while, then changed covers and filled with 85w140 Royal Purple until about 200k... same fill for over 100k, it didn't even change color and the magnet was always clean. I would have ran another fill of RP 85w140 (still have about two gallons left), except its hard to find and expensive.

I recently changed to Schaeffer 75w140, and immediately had chatter. Added a 4oz bottle of Mopar LSD additive and the chatter went away... . 50k later, its still gone. That was 4oz in nine quarts of oil.

As for the comment about most gear oils having LSD modifier in them, most true gear oils do by default because it means it will operate in most applications without issue (so someone doesn't blame the oil for chatter if they needed modifier) and because the additive isn't detrimental except in manual transmissions. Just walk into your favorite parts house and read the bottles... most will state that they will work with LSDs. That's probably why most don't have any chatter when they change gear oils... it doesn't take much LSD modifier to make a notable improvement.

 

[Kry226]

Regardless of the AAM requirement, some fluids need additive... I had to add 4oz of Mopar additive to my current fill to make it quit chattering under load (it feels like two blocks of rubber sliding past each other).

I have found this to be the case with my truck too. I get a bit of chatter when taking off from a stop while towing the travel trailer. But I have found just about any brand of diff additive adequately cures the chattering.

 

[HBarlow]

2004. 5... 11. 5aam.


The factory fill was fine, but it got dumped at 50k.

I ran Mobil 1 75w90 for a short from 50k to 75k, until it turned extremely dark and smelled burnt. I still have this oil in the front differential and it has stayed completely clear since installation (unlike the rear diff), but it doesn't see much use with the DT kit either.

I ran 75w90 Royal Purple for a short while, then changed covers and filled with 85w140 Royal Purple until about 200k... same fill for over 100k, it didn't even change color and the magnet was always clean. I would have ran another fill of RP 85w140 (still have about two gallons left), except its hard to find and expensive.

I recently changed to Schaeffer 75w140, and immediately had chatter. Added a 4oz bottle of Mopar LSD additive and the chatter went away... . 50k later, its still gone. That was 4oz in nine quarts of oil.

As for the comment about most gear oils having LSD modifier in them, most true gear oils do by default because it means it will operate in most applications without issue (so someone doesn't blame the oil for chatter if they needed modifier) and because the additive isn't detrimental except in manual transmissions. Just walk into your favorite parts house and read the bottles... most will state that they will work with LSDs. That's probably why most don't have any chatter when they change gear oils... it doesn't take much LSD modifier to make a notable improvement.

That claim printed on bottles of gear lube is not evidence that the products contain friction modifier.

 

[steved]

That claim printed on bottles of gear lube is not evidence that the products contain friction modifier.

Then I guess we can also not believe oils are synthetic or that an engine oil is approved by Cummins since that is also "printed on the bottle"?? Maybe your Dodge isn't even a Dodge, maybe its a Ford with Dodge badging? :-laf



You make me laugh at times Barlow... have a nice day.

 

[HBarlow]

If the label states this product contains friction modifier I would believe it does.

If, on the other hand, the product label states this product is compatible with limited slip differentials, the product may or may not contain friction modifier.

You may be unable to differentiate between those two statements, I am not.

 

[RChriste]

This is interesting, my brother's `06 3500 dually was in the shop for rear diff noise last week and an oil change(Mopar) with friction modifier cured it. From what I'm told there were no signs of excessive wear, though he has towed a good size 5ver around the country a few times since the truck was new.



So I am guessing that the additive, which isn't supposed to be needed, wears out?

 

[steved]

If they make the claim, they would need to have something to make an LSD work would they not??

Again, you make me laugh...

 

[HBarlow]

If they make the claim, they would need to have something to make an LSD work would they not??

Again, you make me laugh...

Perhaps you laugh to cover your embarrassment when someone calls you on something you wrote that is clearly inaccurate?

 

[steved]

My whole point is that you are trying to pick up on a slight detail, that doesn't even matter in the realm of things. And I'm trying to figure out why you are even chasing it...

You stated "the AAM axle used in 2003 and newer Rams does not require an additive. The friction modifier additive was required in Gen II Dana axles. " If the AAM11. 5 LSD supposedly doesn't need LSD modifier; why would the choice of oil, regardless of it being LSD or non-LSD, have any impact?? So why would you even care if it contains LSD modifier or if it is LSD compliant? What impact does it have to the OP? What does it matter?

I have first hand experience with LSD chatter in my own truck, and have fixed the problem with a bottle of LSD additive. Period. I didn't get that from the manual.

Have a nice day.

 

[HBarlow]

This is interesting, my brother's `06 3500 dually was in the shop for rear diff noise last week and an oil change(Mopar) with friction modifier cured it. From what I'm told there were no signs of excessive wear, though he has towed a good size 5ver around the country a few times since the truck was new.

So I am guessing that the additive, which isn't supposed to be needed, wears out?

The differential lube wears out but unless your brother or an uninformed dealer tech put differential lube in it containing an additive an '06 did not require a friction modifier and the factory fill did not include a modifier.

Perhaps your brother had not previously changed the differential lube and changing it eliminated the sounds.

I put 230,000 miles on an '06 that never had a drop of additive, friction modifier or otherwise, added to the ordinary synthetic lube and it was never noisy. It pulled heavy trailers all of the time I owned it.

For some TDR members fuel and lube oil additives are a religion and they probably add a small amount of additive to their beer or soft drinks. I've put as many miles on my trucks as most and, except for my first Dodge, an '01 with a Dana 80 axle, have never used additives or seen a need for them.