2nd Gen Non-Engine/Transmission Diff Fluid change, Fluid recommendation

[Pit Bull]

I bought my truck used. Don't know if the Diff fluids have ever been changed. Truck (see sig) has 39K miles on it now. Have a Dana 80 in the rear with LSD. The front has the snow plow option so I don't know if that requires more fluid? What is the recommendation for fluid? What kind of synthetic can I get at the local auto parts store that is any good or is their someone on this site that sells Amsoil and can ship it to me? How much is the Amsoil per quart and do I need a modifier with it for the LSD? Now the big question, how many quarts do I need to change the front and rear Diff's? Also, if I use a synthetic does it void my 100K mile diesel wrap warranty for the diff's and axles? Sorry if these are stupid questions, I just want to do what is best for my baby and not lose my warranty. Any help would be appreciated.

Thanks

Denny

 

[Dennis Garrett]

The only synthetics in my truck are in the rear end. I use Amsoil 75-90, found it at an auto supply store. I think is uses about 3 quarts, & I always have to add the Mopar limited slip additive. Less rolling resistance=better fuel mileage in cold weather.

 

[FourBarR]

diff. fluid type.

just went thrrough a problem with this. using quaker state synthetic 75 90 . had used it in previous change with no problems. made mistake of using non oem additive . lsd had chatter problem. drained out and replaced with quaker state and dc additive . no more problem . in dana 70 takes 7 pints with one 4 oz. bottle of addative. hope this is some help.

 

[QRTRHRS]

Denny, I believe the rears are synthetic from the factory. I use Amsoil series 2000 75-90 but with no additive. Some feel a use for the additive with this oil and some don't. I forget the amount, it's been some time. I would assume that at 39k yours is factory.



You need to pull the rear covers to drain the oil. I used Ultra Black RTV to put the cover back on. Have you read anything about the Mag-Hytec aluminum rear cover? Increase your Dana 80 oil capacity plus have a dip stick to check the level. And one more thing, jack each side of the truck to drain the oil out of the axle tubes too.

 

[rrl989]

On my last change, I had to add in a second 4 oz. bottle of the stink oil to get rid of the clatter. One thing, based on experience, absolutely DO NOT over fill the rear. A week after I did, I was leaking from the pinion and D/S axle seals. Stay below those threads the distance as spec'd by the manual.



RonL

 

[Joseph Donnelly]

Among synthetics, 75-140 should give better protection than 75-90, particularly in hot weather, and less tendency to leak through the seals. Synthetics have additives to help swell the seals so they won't leak. Most petro oils have stuff in them naturally to do this, according to Kevin Dinwiddie. You will find list members using, in alphabetical order, Amsoil, LE, Redline, Royal Purple, Torco, maybe others that I don't recall at the moment.



Among petro lubes, LE 607 stands out (90 wt. , and very much a premium lube).



Mag-Hytec makes an excellent cover that increases lube capacity and helps oil get to the side bearings. On Dana 70s, the drivers' side outer bearings tend to starve for oil and burn up. The cover also raises the lube level. If you look carefully, you will see Dana themselves have raised the level over the years. Mag Hytec is one source for the limited slip additive and for LE oils, BTW.



If you ask for brand preferences you will re-start the infamous Lube Wars for about the 87th time

 

[Ray J]

At 10K I put on the Mag-Hytek cover and changed to Amsoil 2000, 75-90 at the same time. Did not use any "stinky".

Am now at 21K and have had no chirping of any type yet. I guess its the luck of the draw.

 

[LSMITH]

I use Mobil 1 75-90 in both diffs. You can get it nearly anywhere, it is reasonably priced and works well. I picked up 1-1. 5 MPG switching to synthetics in both diffs.

 

[RJOL]

Check out issue 32, page 88, for a good article on changing differential fluid...

 

[Pit Bull]

Thanks, Since the lube from the factory is synthetic is the lube the dealer would use to refill synthetic? (my dealer is great and will be doing the change for me) (Plus it is to cold for me to crawl under the beast, he won't fit in my garage ) Also do I really need to change the front diff since the truck is only two years old and it has only been in 4 wheel drive about 50 miles in that time period (no leaks, both diff's are dry as a bone). Yes I would love to have the Magtech cover and was going to put off changing the fluid until I could afford it. Since this truck is a daily driver with no heavy hauling or pulling, (it has 39K miles on it now). Would it hurt anything to wait until I have 55K miles on it and can afford the Magtec cover to do the change? I have the 100K mile diesel wrap warranty and my driving fit's the decription in the owners manual that says the fluid never needs to be changed (now I don't go along with that way of thinking) but would love to be able to wait another approx 16K miles and do the Magtec and change at one time. I won't do that if it might screw something up. Please give me your thoughts (man I wish I had the money my wife just spent on redecorating the house, then I could get the Magtec cover now )

Thanks

Denny

 

[Sled Puller]

I do not believ it is synthetic from the factory, otherwise the book would not state: "Change to synthetic if your towing"



The dealer will use a suction gun, not take the cover off.



Tha Dana 80 holds 5. 05 qts

The Dana 60 holds 3. 8 qts



Keep in mind the spider gears are turning in the front all the time, and gear cases draw moisture. I suggest changing once a year if this truck is a keeper.

If you would have seen my fluids when I bought my truck with 26,000 miles, you would change yesterday!



I doubt anything will hurt it a few more thousand, but we tend to over maintence out here!



The snow plow package is heavier front springs.

Going to a synthetic will not void you warranty, but will extend the trucks life.



Regardless of the lube choice, be sure to do several tight figure 8's after your done, to get the LSD clutches lubed up again.



There is dozens of Amsoil dealers on this site, and some pretty good deals going on at Diesel Ram .com.

Gene

 

[SHOOT1SAM]

Denny, no one seems to have addressed your "voiding warranty" question: the answer SHOULD be no.



I may be wrong, but I do not believe that the trucks come from the factory with synthetic lube-my owners manual states "Dana Models 80 and 70 rear axles contain SAE 90. " It also states "Limited-Slip Differentials require the use of a friiction control additive @6. 5% of lube capacity. " Key word there is REQUIRE.

(One more quote) "... reduce the potential for rear axle overheating by replacing the rear axle lubricant with an SAE 75-140 synthetic gear lubricant. "



So, replacing your differntial fluid with synthetic SHOULD not void the warranty, IF, you use the 75-140 and the friction modifier.



I'm not saying you need the heavier fluid and the modifier, but IF you are seriously concerned about them finding a loophole to void your diesel wrap warranty, I would suggest only using the recommended fluids/weights/modifiers that your owners manual calls for.

 

[KYOUNG]

Axle Lube

I changed both axles for the first time at 220,000 miles! The lube in both looked & smelled like new! I refilled with Amzoil 75-90.

 

[C Schomer]

I don't have megapower or tow very much weight but I'm usually running right with the cars out on the freeway. From watching the diff temp, speed raises the temp way more the hard pulls. 75-80mph on the highway runs a LOT hotter than pulling up to Eisenhower tunnel at 65. I put in Ams 2K75w90 at 12k miles and had to use modifier - and yes, I did 8s for 30 minutes. The ring and pinion teeth were smooth and shiny at that time. 13400 miles later I had the infamous ring and pinion singing noises. The teeth were smooth but dull in color. I switched to RP Maxgear 75w90 and after a couple K miles, the noise was gone. I didn't need modifier but I get a little chatter on the first corner when cold - then it's completely gone. I have 10k on it now and haven't looked at the teeth yet. I think any 75w90 is borderline for hard usage in these trucks. BTW, I used Valvoline semi-syn 85w140 with no modifier for 4k miles before the Ams with good luck but my power was lower then. I'm getting the Mag cover this spring(and check out the teeth) and might try the RP75w90 again with that before going to a 140.

 

[Pit Bull]

Re: Axle Lube

Originally posted by KYOUNG

I changed both axles for the first time at 220,000 miles! The lube in both looked & smelled like new! I refilled with Amzoil 75-90.

I think at this point I will wait a few months until I can afford the Magtech rear cover and do it right the first time. I never drive over 70 mph for any substained distance and it is alway on flat ground. Most of my highway driving is 60 - 65 mph for about 15 to 20 miles and I never have a load. Since DC does not even show that my usage requires a change, doing it with the install of the Magtech at around 50K miles is anal enough. If it was new when I got it I would of changed it a 10K miles but since it now has 40K miles, another 10K can't hurt, and if it does the warranty can pay for it . Thanks for the advise.

Denny

 

[Mikestruck]

My name is Michael. I have a 2012 Dodge Ram 3500 Crew cab with a flatbed. My rear diff gets too hot to touch just driving to town and back home. I guess about 26 miles. My truck only has about 10,000 miles on it. I am going to use it heavily to tow 5th wheel and bumper pull travel trailers when I retire from the Army. Can someone on here give me some advice on what oil to put in both of my diff's for this type of work?
I would appreciate the help.

 

[fest3er]

Bear in mind something that's been pointed out from time to time. 75W-90 is the same viscosity that was used in pickups 40 years ago. And they had far less torque and HP. Were I to do it again, I wouldn't use less than 75W-110 with extreme pressure additives (like Amsoil's Severe Gear lube) in a diesel-powered pickup. And if towing/hauling heavy and/or regular, I wouldn't use less than 75W-140.

I would only ponder using 75W-90 if I were in arctic conditions (like never rising above -20°F for weeks on end).

 

[Mikestruck]

Thank You. I should use 75W-140. What brand would you recommend?
I appreciate the help.
Michael

 

[Mikestruck]

The Dodge dealership checked out the rear end of my truck. They checked the fluids and temperature. They said that the truck is fine. They told me not to use any other oils in the diff's other than what Mopar recommends. There is an additive in the oil that is in the diff's. Without that additive the truck won't pull. That is what they told me. The dealership also replaced the left tie rod. It was a recall. I didn't have to pay anything. They said that my truck has a 5 year or 100,000 mile warranty on all the drive train components. It has a 36,000 mile warranty on everything else.
The dealership told me to bring the truck in when I get 60,000 miles on it and they would change the diff fluids.
The dealership also told me that pulling fifth wheel travel trailers is not hard work for my truck.
I guess all is good.

 

[Cummins12V98]

AMZ/OIL Severe Grae 75-110 over 28K combined load works great.