The New Diff Cover for the Ram Heavy Duty Pickup is a Work of Art

The New Diff Cover for the Ram HD is a Work of Art

A precision-machined aluminum differential cover is part of the new Max Tow package for Ram Heavy Duty pickup trucks. We want to frame it on our wall.

What suspension travel and articulation is to off-road trucks, heat dissipation is to heavy-duty tow rigs. It doesn't matter how much torque your truck has if its hardware is fried.

The flared fins (we count 38) on this diff cover extract friction-generated heat from the 4.10 ring and pinion housed inside the axle's differential. The design — also called a heat sink — does this by increasing the cover's available surface area via a network of deep channels that are also designed to encourage airflow, further reducing temperatures.

Compared to a standard smooth-faced axle housing shield, it's over the top and wild-looking, but it performs.


that looks like it will need a weekly pressure washer blast so it doesn't cake up completely. I can see that doing just the opposite of what it was intended for, if not kept clean.

eh... spay it with some of the wife's pam so nothing sticks to it. I love pam... keeps fish from sticking to the pan, wet snow from clogging up the snow blower and mud from sticking to the new dodge heavy duty differential cover.

performance cover.look the same...good job dodge,,is not ford thing to do this, watch all the negative comment..

Nice for being a factory thing.

I do have a question however.

AAM makes both the GM and Ram front and rear axles. GM now has a larger bolt pattern(8x180), and beefed up axles. Focusing on just the rear axles(the GM ones I think have larger shafts, tubes, etc), does the Ram still have the old 8x6.5 bolt pattern and pre 2011 axle it shared with the 2010 and back GM trucks? Or has Ram recieved the same axle upgrades as the GM?

Ford has been doing this since 2008.

What does the inside look like? [how is heat transfer to the cover]
Can this aid in fuel mileage by allowing for thinner differential oil, say 75w-90?

Dirtbikes were once air cooled and I never had a problem with overheating in mud.
Simple ideas are always the best solution.

Does it matter who was the first one to put it on a truck?

As was reported, it's a heat sink. Just like on a small air cooled engine (lawn mowers etc). If the fins get full of dust, debri, or mud, it won't cool properly and will heat to a much higher level. Most would never get this full of crap though. It's a good idea. I think many of the other trucks use covers with fins for strength more than a heat sink.

This is just extra toppings for your ice-cream.
I have never seen a commercial truck with a heat sink

Yall know ford has had finned diff covers on the f250 since 2008 M.Y.?

Nissan has one on the titan also... so does Subarus come to think of it.

@kbowman: Yes, but the aren't finned to quite the extent this one is. Titan's was added after launch to help with durability.

I think that this is a step in the right direction for Dodge. It may not be noticed by the general public, but hardcore people that get to know their trucks will notice. Or, it may be part of the general walk-through when a person buys this vehicle new.


Is there an increased amount of volume? Maybe Dodge will put less fluid in the diff?

That is beautiful!

I hope that Mopar offers one available in the parts department for my A.A.M. 10.5" axle, soon. Only if it has a drain plug at the bottom, though.

I'm surprised AAM does GM and RAM it just 1500 models or do they do heavy duty models as well? If they do HD, somebody send GM a note that the next line of GM HD's had better have a solid front axle LOL!

What is so great about the solid front axle? I see no benefits

@Bigger Bob
It's called axle articulation. You should read Four Wheeler magazine and then you know why some people prefer a solid axle. But then again it's a matter of preference like everything else out there. Depends on what you want or need. I myself would prefer a solid axle on my next truck. Wish someone made a half ton with one.

I have read about them, I just don't understand why people prefer them over the independent suspension as used in gm hd trucks. I have driven both types many times and find the independent rides so much better, and being rated as strong as the front axles dodge and ford use, I see no point of getting the solid.

Not all that amazing since Ford's had a heatsink on Diesel trucks since the 6.4L started in January 2007.

@02tbird: As I said earlier, it's not machined like this one. That's the only point I'm making is that Ram's new diff cover is amazingly intricate.

Yeah..when I go out to buy a truck I only buy the one with the BIGGEST fins on the Diff cover....because thats important and its not like you can go out an add one from an aftermarket company.


A.A.M. makes the axles for heavy duty models as well.

Bigger Bob-

Solid axles are stronger. How many pickups do you see with independent rear suspensions? Solid axles have better off-road articulation. When one end of a solid axle rises (over an obstacle) it exerts force on the opposite end to put more pressure to the ground on the tire to help with traction. With an independent suspension; the tire that rises (over an obstacle) also lifts the rest of the vehicle and reduces the pressure to the ground of the opposite side of the axle. It is also less costly and less involved to install a suspension lift on a solid axle 4X4.

Independent suspensions belong on the street.

It's not machined, it's cast aluminum. Pretty, but not that difficult to make...

Mike, You did a good job bringing something different to the article page. Thanks and good write-ups.

Synergy, you don't have to be a smart@ss about it, Mike was just doing something different that I think is interesting.

I agree that solid axles are stronger, hence two of the three automakers use them on medium-heavy duty trucks. I presonally could care less as olng as it works. My F150 IFS needed a set of upper and lower ball joints shy of 120K. I still could care less either way, as most people that drive trucsk could as well. As long as the axle is effective, why worry unless you rock crawl or hard core offroading. Just sayin, not to flame anyone's preference.

But still no drain plug? WTH?

So it looks like the AFE cover is probably still the way to go.

@George The spec is already 75w90.

The drain plug is on the bottom of the axle housing

I can understand the concern for grime buildup causing problems. I own a 2000 M Coupe equipped with differential vents that hang down like fins and significantly cool the differential. It works great, and looks pretty cool. I have never had a problem with it getting dirty, at least to the point of losing functionality. I could see a truck being offroaded and throwing some mud or sand up there, but shouldn't you spray it down afterwards anyway? The rest of us who actually clean their cars would appreciate it.

D-Ray : it may work well on your BMW, you don`t drive in the mud, don` you. Such fins are designed mostly for transfering heat out of diffs while towing. When you want to play hard in the mud fins aren`t efficient. But it`s a step in the right direction - I mean they finnaly put attention to details.

Unless they changed the housing for 2011 as well then there won't be drain plug as the current housing hasn't got one and from looking at the pic the new cover doesn't have one. They do have reusable gaskets though. And the factory oil is 75w90 at least for the 2010 MY.

I have a Mag-Hytec cover on my differential on my 2001 Supercrew 4x4 (9.75" ring gear) and a TCI Industries large sump transmission pan with fins like this (maybe not as deep, but I digress) and they have yet to cake up with mud, dirt, grime, etc. Why haven't mine "caked up" or somehow become less effective at their job? Because you people are pulling at straws here and you know it. It will work as intended, bet on it!

Good job Dodge, damn neat piece of owrk.

@ Red 4x4 - something like this is a great idea only if one's favorite brand makes it ;)

Blaming brand bias is a lazy argument. If you live and drive only on paved roads it might not get too bad. Where I drive the cover would be caked in dirt/mud from before you even see this "work of art." One trip down my driveway and road would all it would take. It's not something I would want to have to worry about on a daily basis.

Looks like a nice and functional piece...good job Ram. Of course, the Ford fanboys can't stand for the homepage to not be littered with Ford articles so they have to come and immediately write this off as a "Ford-first upgrade". Ford boys need to get over themselves, your trucks aren't that great.

For those saying it will become caked with mud and useless, so what if it does? For most it will funtion as intended for the duration, and when it gets covered voila your diff cover magicaly transforms into the smooth covers that have been on axels for the last 100 years until you wash your $50,000 truck

Maybe this cool diff cover will inspire GM to put cool REAL metal louvers on the hoods of their diesels.

I drive everywhere, Sand, Mud, Pavement, gravel, you name it. I only see this happening if a person was to BACK into a pile of mud or drag axles backing up. Going forward, this diff cover will operate as intended. I really do not see the issue hee, I have never seen one going down the road on a superduty "caked with mud" or anything, never!

Jordan, lou:
exactly! Since this is not the brand preference of some folks, it is not a good idea etc.

dirtrider: good point, people are pulling "straws" out of their ass, that is all.

JordanL: damn, a functional drain plug would be great, wonder why they left it out? Maybe because the diff has sythetic in it and after 100K it is encouraged to take the cover off and inspect the inside of the diff, I wonder this myself?

It kinda reminds me of some of the finned heads on some of the air cooled dirt bikes I used to own.
Maybe Suzuki can sue them for design infringement?
Worked for Ford against Ferrari. LOL.

"I have one...."like this (maybe not as deep)"

So you don't have one like this.

@ Red 4x4 Maybe it has something to do with getting customers in the door to have the diff oil changed. I perfer to take the cover off so the internals can be inspected but as a mechanic I have the resources to do this easily and free.

Why did Ford ever fin their cover the PSD doesn't make enough steam to ever heat the diff?

Solid front axles are great for rock climbing, thats about it. On road comfort sucks, off road isn't very good unless rock crawling. Those lame trophy trucks racing baja use IFSs.

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