2006 3500 DRW 4X4 Diff Oil Question

[steved]

The extra heat is from the insulating effect of the oil, and pretty much insignificant in terms of the temp difference between the two...



Personally, I run the heavier stuff because it cushions better and resists wiping better in most cases. I actually gained mileage changing from 75w90 to 85w140 and my magnet is always clean indicating the 140 is probably doing a better job.

 

[AH64ID]

I believe if you read the section the 15k is stated, that's "severe duty"... I think I remember there being no specified change interval for "normal duty"...



I have 80k on my 85w140 and it looks like I just put it in, but I also have 9qts of fluid with an aluminum cover. Having the added fluid and heat disappation of any aluminum cover is a significant benefit. I would not hesistate to run a minimum of 50k or more.

But have you read the description of schedule "A". . well I guess I mean Schedule "B", as schedule "A" says if you don't do any of the following...



To sum it up, if you spend 99% of your time empty on the fwy you fall into schedule "A", everything else is schedule "B"



I mean serious schedule "A" is a joke. . 15K miles on dino oil (engine oil), with the in-cylinder EGR. . are they kidding I have a bypass and run good amsoil and 20K will probably be where I change it.

 

[Wingate]

yeah... its 8 qts. in the rear with the Hy-Tec... I love my differential covers, they have definitey dropped the oil temp. when pulling heavy loads.

 

[steved]

But have you read the description of schedule "A". . well I guess I mean Schedule "B", as schedule "A" says if you don't do any of the following...



To sum it up, if you spend 99% of your time empty on the fwy you fall into schedule "A", everything else is schedule "B"



I mean serious schedule "A" is a joke. . 15K miles on dino oil (engine oil), with the in-cylinder EGR. . are they kidding I have a bypass and run good amsoil and 20K will probably be where I change it.

And you think the engineers that wrote that service schedule had your truck's health in mind, or their pocket book??? That differential will probably go just short of forever without ever changing the oil; but in 100k of "warranty", you will change it almost seven times... lots of money for DCX.



In all reality, it is a VERY simple gearbox. These AAMs are not significantly different than the previous Dana. Same roller bearings, same roller bearing cones, same ring and pinion designs, and same seals. And our cohorts with the second gens drive the same as we do, without a severe change interval as the AAMs. What part of the AAM is more susceptible to failure???



It boils down to comfort... the 15k interval is ridiculous, but if you feel its needed, its your money. Those of us that have been around these types of differentials any amount of time realize the schedule is ridiculous and feel comfortable to run the oil a more realistic interval.

 

[Boomer1]

Ok guys now I'm confussed here. I ordered Severe Gear 75W-110 for both diffs. thinking if I go in the middle I would have all areas covered. Now I'm wondering if I ordered the right oil now. I don't on plan to change this again for awhile unless something unusal is picked up with the magnetic dipstick or plugs as that is one of the reason's I went with Mag-Hytech covers. I don't tow every day either. So... ... . should I have went with the 75W-90 instead. I was thinking that the 75W-110 would have given a little better protection and run a tad cooler. What should I do as I already have a case of the 75W-110???



Thanks In Advance

Dan

 

[steved]

The 75w110 will serve you well...

 

[Boomer1]

Thanks steved, that's what I will go with!

 

[WoodChuck]

My owners manual calls for 75w-90. Anything heavier will run hotter and decrease milage.

If you tow heavy a majority of the time in high temps I could see justifying the heavier lube. For me the 90 is clearly the best choice.

 

[steved]

My owners manual calls for 75w-90. Anything heavier will run hotter and decrease milage.

If you search, there is supposedly a Dodge "memo" stating that if you tow, you should run 75w140.



I run 85w140. My mileage increased by switching from 75w90 Mobile 1 to 85w140 Royal Purple... and I have the mileages documented. The difference between a 90 and 140 is insignificant in the overall scheme of things in these trucks. I even run 85w140 in my 97 Outback's differentials (a low HP 4-cylinder), and see no loss in mileage (it would be more apparent in this case because its already low HP). These are real world experiences in my vehicles, not "I heard it on the internet".



And again, the difference in temps between one versus the other is insignificant when you consider the overall operating temp of the differential. And I'd bet you'd see the 90 run HOTTER during towing than the 140.

 

[AH64ID]

If you search, there is supposedly a Dodge "memo" stating that if you tow, you should run 75w140.



I run 85w140. My mileage increased by switching from 75w90 Mobile 1 to 85w140 Royal Purple... and I have the mileages documented. The difference between a 90 and 140 is insignificant in the overall scheme of things in these trucks. I even run 85w140 in my 97 Outback's differentials (a low HP 4-cylinder), and see no loss in mileage (it would be more apparent in this case because its already low HP). These are real world experiences in my vehicles, not "I heard it on the internet".



And again, the difference in temps between one versus the other is insignificant when you consider the overall operating temp of the differential. And I'd bet you'd see the 90 run HOTTER during towing than the 140.

I would like to see the memo, This one says 75w-90... The only thing I have ever seen is 75w-90. I also talked to AAM about this and they say that unless you tow at or above GCWR thru death valley in summer that 75w-90 is all you need.

 

[steved]

I would like to see the memo, This one says 75w-90... The only thing I have ever seen is 75w-90. I also talked to AAM about this and they say that unless you tow at or above GCWR thru death valley in summer that 75w-90 is all you need.

There has been discussion about it... it is a memo, not a TSB (its not a "problem", but a recommendation). I know someone posted about actually seeing it at a dealer before... I didn't care at the time since I was already running a different oil.



Typically, lighter gear oils are thought to be a compromise and are thought to not protect as well as heavier gear oils for the reasons I stated before... there is a lot of discussion of this on BITOG.



And again, its a personal preference... use the schedule dictated by chrysler, don't change the oil at all, or use a compromise of an interval that gives you a warm fuzzy feeling... if that's 15k, then its 15k.



And further, you stated you're changing your Amsoil at their recommended interval of 50k... what makes their schedule of 50k better than Chrysler's 15k schedule??? You stated the rest of the Chrysler schedule was flawed (changing engine oil at 15k), what's to say the gear oil change interval isn't flawed? Remember, some stupid human wrote that manual that some of us think is the final word on everything Dodge truck.



And finally, keep in mind, it is ONLY a recommendation...

 

[WoodChuck]

I know someone posted about actually seeing it at a dealer before...

Sounds like some of that internet he said or she said that you said to be leary of in an earlier post.

 

[WoodChuck]

not "I heard it on the internet".

There it is. :-laf

 

[steved]

The source was more reliable than most... believe what you want.



You can search on this forum if you desire.

 

[AH64ID]

The source was more reliable than most... believe what you want.



You can search on this forum if you desire.

Again I would like to see it. . My source was AAM, not Dodge.