Banks Power discusses hi cap diff covers

[GCroyle]

Guys,

Responding cause ain't much else going on today. But the one that I remember and it impacted my next move was view of running lube shown in the clear plastic stock and flat back demonstrations.

The stock funnel flow pattern of lube vs the flat wall and right angle at the top flat back effect IIRC caught my attention.

I've had one (Mag) for quite a while and it was time for lube change. I dug out the OE cover and old seal and changed it out and saved several quarts on refill volume. My truck is in semi retirement, not a daily driver the Bug is the DD but I need it to pull the Airstream and that's a decent load.

VMMY

Gary

 

[KATOOM]

Just because he is a salesman doesn't mean everything he says is, um, inaccurate, lol. Do you dispute aerated oil is bad? Do you dispute that, all things being equal, more oil doesn't make anything run cooler? Do you dispute that churning up more oil takes more energy? The videos speak for themselves or do you think that they are staged or fake in some way?

How much energy is actually saved in the real world can be debated. Since you don't hear of frequent bearing failures with the flat back covers, it can be debated if any real harm is being done by churning and aerating more oil.

Of course he cherry picked the most impressive data which will show his product in the best possible light. The limited data he does supply in itself is telling, meaning that his product might not be significantly better than the alternatives or he would have published all the data. I don't care about his cover, like I said I would go with the max tow cover if I felt the need. I agree that it would have been nice to see all the test data (and see the max tow cover included in the testing). That doesn't mean he is wrong or doesn't have good points to ponder. YMMV

Is aerated oil bad?...yes. But was anything he showing you in his videos actual aerated oil???...No one knows because he never tested it. All differential oil gets that look when its running. To support that statement, there just happens to be a few videos of factory shaped clear differential covers on YouTube. Take a look at what the oil looks like when the vehicle drives. Ironically is looks EXACTLY like what he tells you is "aerated" oil. Looks like Gale was BS'ing everyone. Why does no one question how come he didnt show a clear version of the new Banks cover in action? LOL

Do I believe that more oil makes things run cooler?...yes, and no. I'd say it depends on the application and what we're talking about. Again, Gale only talked about what he speculates but never tested anything to actually prove what he said was accurate. That said, in his videos he even talked about GM and Dodge having two different fill levels even though they both used the same axle housing. Should this have been worthy info to know more about?...absolutely, but Gale went about his videos without any testing data to prove what oil level was best based on temperatures or wear or anything. More BS'ing? Yup...

As for more oil being better... I've mentioned it many times before but I'll keep mentioning it. Years ago I installed a dash mounted temperature gauge for my stock differential cover. Then about a year later I replaced the stock cover with a MagHytec. I made sure to keep the same brand/viscosity oil too for a direct comparison. My results?...Very pleased. The differential took longer to heat up and runs cooler overall and the oil stayed cleaner longer. I even raised my oil level because I wanted to assure the outer axle bearings adequate lubrication. Strange that after almost ten years things are still working... I wonder if Gale would be interested to know about my actual back to back testing results.
Also, I'm not disputing how well the max tow cover works. I only have my own testing data, not any other covers. I'm sure the max tow works great too.

Do I dispute churning oil takes more energy and generated heat?...yes, I think thats stupid. Why? Because the oil in a differential is only heated by the ring/pinion gears hypoid action. The taller the gear ratio the cooler the normal running condition because less hypoid action.
And...the carrier is already submergeded in the oil and oil slinging and splashing around is doing nothing but throwing it around for lubrication. The oil whips around the ring and literally throws itself with force on to the pinion. To elude that oil splashing up against a flat surface is a heat generating/energy using problem is absolutely garbage. Anyone who's been around engine mechanics long enough understands that crank windage isnt a problem for low rpm engines even though the oil has to cross paths with a rotating crank surface.
Think I'm wrong? Use a temperature gun and measure the temp of a front differential compared to a rear differential after an hour drive on the freeway. If Gale is right then the front should be just as hot as the rear even though there's no power to it.

Do I think his videos are fake?...well not really but I do believe that he never found the data he wanted to support his claims otherwise he would have used it to prove how other diff cover designs are faulty and damaging. But...they're not. Thus the reason for his cherry picked data and manipulated marketing.

And sorry for the long post...

 

[brods]

You want a long post, lol...

Is aerated oil bad?...yes. But was anything he showing you in his videos actual aerated oil???...No one knows because he never tested it. All differential oil gets that look when its running. To support that statement, there just happens to be a few videos of factory shaped clear differential covers on YouTube. Take a look at what the oil looks like when the vehicle drives. Ironically is looks EXACTLY like what he tells you is "aerated" oil. Looks like Gale was BS'ing everyone. Why does no one question how come he didnt show a clear version of the new Banks cover in action? LOL

In my industry aerated oil is very bad and I've seen my share of it. Some oils foam worse than others, some oils have anti foaming agents added. From the videos, the oil in the clear flat back cover looks more aerated. After they ran for a few hours would they look any different or would they both look equally aerated? We'll never know, so yes he should have ran specific tests to quantify the aeration. A simple test would have been to run the diff at highway speeds for a set time and as soon as the diff stops turning, drain the oil to fill a graduated cylinder. Immediately take a volume reading. Then let the oil sit (typically overnight) until all the air is out and compare that de-aerated volume to the first reading. For the test to be really useful he should test the covers and also test different brands of oil.

Do I believe that more oil makes things run cooler?...yes, and no. I'd say it depends on the application and what we're talking about. Again, Gale only talked about what he speculates but never tested anything to actually prove what he said was accurate. That said, in his videos he even talked about GM and Dodge having two different fill levels even though they both used the same axle housing. Should this have been worthy info to know more about?...absolutely, but Gale went about his videos without any testing data to prove what oil level was best based on temperatures or wear or anything. More BS'ing? Yup...


As for more oil being better... I've mentioned it many times before but I'll keep mentioning it. Years ago I installed a dash mounted temperature gauge for my stock differential cover. Then about a year later I replaced the stock cover with a MagHytec. I made sure to keep the same brand/viscosity oil too for a direct comparison. My results?...Very pleased. The differential took longer to heat up and runs cooler overall and the oil stayed cleaner longer. I even raised my oil level because I wanted to assure the outer axle bearings adequate lubrication. Strange that after almost ten years things are still working... I wonder if Gale would be interested to know about my actual back to back testing results.
Also, I'm not disputing how well the max tow cover works. I only have my own testing data, not any other covers. I'm sure the max tow works great too.

Heat in vs heat out. The main reason (and probably only reason) "deep pans" with more volume run cooler is because they have more surface area to radiate the unwanted heat. The change in the quantity of oil just adds more thermal mass to hold more heat, not any way to get rid of more heat. We deal with tanks from 600 to 40,000 gallons of oil. Never does the quantity of oil factor in to the chiller sizing equations. How much heat is being put into the oil drives the size of the chiller and how much surface area is required for the heat exchanger. Most of the heat comes from the pumps, which are basically throwing the oil out the pump discharge like the ring gear is doing in the differential, just more efficiently of course. These pumps are adding heat because of the friction from moving the oil. There is no friction from hypoid gears heating the oil, the pump bearings are not cooled by the oil, the only other source for heat is the pump shaft and seal and that amount is small (or the seal would get destroyed). Pumping and churning of oil takes energy and creates heat.

Do I dispute churning oil takes more energy and generated heat?...yes, I think thats stupid. Why? Because the oil in a differential is only heated by the ring/pinion gears hypoid action. The taller the gear ratio the cooler the normal running condition because less hypoid action.
And...the carrier is already submergeded in the oil and oil slinging and splashing around is doing nothing but throwing it around for lubrication. The oil whips around the ring and literally throws itself with force on to the pinion. To elude that oil splashing up against a flat surface is a heat generating/energy using problem is absolutely garbage. Anyone who's been around engine mechanics long enough understands that crank windage isnt a problem for low rpm engines even though the oil has to cross paths with a rotating crank surface.
Think I'm wrong? Use a temperature gun and measure the temp of a front differential compared to a rear differential after an hour drive on the freeway. If Gale is right then the front should be just as hot as the rear even though there's no power to it.

My front diff housing was 157 F after an all-day drive in 2wd. That was the icing on the cake for me to get a freespin kit and stop wasting all that energy as well as to reduce needless wear and tear. Your windage example is a good one. Why do we have to check the oil level after the engine has stopped and the oil has time to get back in the pan? Because the operating oil level is lower than the at rest level. That operating level is (or should be) selected to reduce windage among other things. Raising the operating level is not a good idea and may cause excessive windage. Similar thing with an automatic transmission. There is no reason to think a rear end would be different. The designers pick an operating level for a reason. By adding way more oil capacity to the rear and filling it to the stock at rest level means that the actual operating level of the oil will be higher than the designers wanted.


In the video it sure appears the plastic flat cover is slinging significantly more oil in the diff. Maybe it is an illusion, but I doubt it. If it is moving more oil that means more mass being moved which means more energy is required to do it and that adds heat. Does the larger heat transfer surface of the flat cover dissipate that extra heat? From your measurements and Banks measurements the answer is yes. I still agree with you: show us the raw data, not just the hypothetical gallons saved extrapolated data. But.... the lack of raw data doesn't mean he's wrong.

Do I think his videos are fake?...well not really but I do believe that he never found the data he wanted to support his claims otherwise he would have used it to prove how other diff cover designs are faulty and damaging. But...they're not. Thus the reason for his cherry picked data and manipulated marketing.

And sorry for the long post...

Its all good. The goal here it to objectively consider what is really happening in the diff. A long answer means you are thinking about it rather than just getting defensive that your chosen brand of accessory is being questioned.

 

[Regcabguy]

Gale Banks reminded me of Joe Biden in this video!

He stays on point though. Biden struggles.
BD has a nice cover at a bargain price.
https://www.dieselpowerproducts.com...e+Abandonment&utm_content=BA+Product+Browse+2

 

[KATOOM]

My front diff housing was 157 F after an all-day drive in 2wd. That was the icing on the cake for me to get a freespin kit and stop wasting all that energy as well as to reduce needless wear and tear. Your windage example is a good one. Why do we have to check the oil level after the engine has stopped and the oil has time to get back in the pan? Because the operating oil level is lower than the at rest level. That operating level is (or should be) selected to reduce windage among other things. Raising the operating level is not a good idea and may cause excessive windage. Similar thing with an automatic transmission. There is no reason to think a rear end would be different. The designers pick an operating level for a reason. By adding way more oil capacity to the rear and filling it to the stock at rest level means that the actual operating level of the oil will be higher than the designers wanted.

We're obviously seeing most of all this eye to eye...but I just wanted to point out a couple things in your post.

What you found your front diff temp to be after driving around in 2wd is proof that the gears moving about is generating heat. The additional heat in the rear diff is from power load hypoid friction the front isnt experiencing. Speed of the R&P is also a huge heat generator too, so the faster you drive the hotter the differential gets. I see this firsthand on my dash gauge monitoring my rear diff too...
Not to get off topic but using a 75-140 will also run about 10*-15* hotter than a 75-90 weight fluid due to the added viscosity friction.

Nonetheless, I can drive unloaded at 70 mph and after awhile the rear diff will run in the 160* - 175* range. Loaded towing a 14k trailer while doing only 55-60 mph, the same diff will be around 175* - 190*, depending on ambient temp.

My front diff also reaches around the 130* range (after awhile of driving on the freeway) and my truck has the CAD front axle, meaning the only things moving are the spider gears and a very slow rotation of the R&P from viscosity drag. I would imagine if I had a non-CAD (like you) that I'd see temps a little higher as well.

As for fluid level, yes I agree that the designers pick a certain level for their specific design R&D working with lubrication and heat expansion. Coincidentally most diff levels are about half way up the carrier, meaning the R&P is always submerged and while driving the fluid is hopefully adequately pushed out into the tubes and lubricating the wheel bearings at all times. (I think most people forget that those bearings are lubed by the diff fluid too)

That said, adding a larger capacity cover does NOT increase the operating level. The fill level is going to be the level of fill no matter if there's 4 quarts or 4 gallons. The oil "level" does not rise with the increase in volume of fluid when the diff cover is designed to hold a larger volume. That would also mean that anyone who installs a larger volume engine oil pan on their car/truck is also raising the level of the oil in the pan. But we know thats not what happens...
It would be physically impossible to put more oil in a differential with the only fill hole being on the side of the cover. Well...I guess if you pumped it in with a high volume pump you could "cram" it in by force... But no one is doing that.

So Gales statement about fill levels with "flatbacks" is completely false.
I myself only chose to raise the my level a little because, it was my choice to do so, and the MH cover has a fill hole on the top for easier filling. There's still an overflow bolt hole though to prevent overfilling...

Good discussion too.

 

[brods]

Yes ring and pinion friction and bearings add heat. So does flinging the oil. And as you have seen, increasing the viscosity causes more heat. That heat is because of the extra energy it takes to move the thicker oil. Moving oil takes energy and adds heat. The only thing to debate on the differential application is if so much heat comes from the gears and bearings that the energy/heat from moving the oil is insignificant. According to your results the viscosity matters (as physics says it has to). According to Bank's fuel saved, the energy required to move more oil is not insignificant, not huge, but moving more oil is still consuming more energy and creating more heat than stock.

As for the operating level being off, that is because of the volume change with the high capacity covers, but I don't know if I can describe it clearly. It is because of the extra volume per mm of depth from the higher capacity covers. Say the diff designer knows (by testing, calculation, whatever) that 1 quart of oil will be out of the sump during highway speeds. So he picks the fill level to be 1 quart higher than his desired operating level. The only cost effective way to add more capacity to the diff is to bump out the cover. Now the volume per mm of depth is more than stock. So when you remove 1 quart from the larger volume the level doesn't drop as far as it did with the stock cover. The more extra oil capacity the cover adds, the larger the volume increase per mm of depth and the less the level drops after removing a quart. If you could cut off the bottom of the diff housing and add a deep pan under the diff, then, with the stock cover, the extra oil would not affect the operating level.

 

[KATOOM]

I totally understand what you're trying to say but...I still dont agree. Yes, forcing a carrier to churn through more oil will consume more energy and create more heat, but my own test results proved that this isnt the case with adding a larger volume diff cover.

The idea that the total volume is going to raise the operating level by forcing the level to remain higher is only possible if the 1) the total volume changes the static level, and 2) if there are other forces at play like pressure variables. IE., a boat will displace the same amount of water whether its sitting in a pond or sitting in the ocean.

You could cut a large hole in the stock metal diff cover, making sure to remain below the stock fill height, and then weld on a drum barrel extending outwards toward the back of the truck. Fill with the amount of fluid needed to bring the appropriate fill height to normal and during operation the R&P will only pick up what oil is within its proximity of cling. The remaining volume of oil cant bombard the carrier with additional fluid unless the static height was higher or unless its being pumped onto the carrier. Think of a manometer...

The only reason diff fluid level drops during operation is because the carrier is picking up the fluid around it and shoving outward away from it. The ring tossing fluid onto the pinion acts as a gallery assuring the oil returns to the sump in a timely manner. The force of fluid disbursement pushes the sump volume outward into the tubes and some of the tossed fluid is pushes towards the tubes before returning into the sump. This is why differentials will work even with low fluid levels until the fluid becomes too compromised from heat and deterioration while the sump stock declines.

Again, good talk...

 

[brods]

I took the liberty of reversing the order of your post (I hope you don't mind) because it seems you get how the diff is moving the oil, but then are missing the volume issue.

The only reason diff fluid level drops during operation is because the carrier is picking up the fluid around it and shoving outward away from it. The ring tossing fluid onto the pinion acts as a gallery assuring the oil returns to the sump in a timely manner. The force of fluid disbursement pushes the sump volume outward into the tubes and some of the tossed fluid is pushes towards the tubes before returning into the sump. This is why differentials will work even with low fluid levels until the fluid becomes too compromised from heat and deterioration while the sump stock declines.

Yes. And this is why any extra volume contained above the operating level will want to flow back to the low point of the operating level and cause it to go up.

The idea that the total volume is going to raise the operating level by forcing the level to remain higher is only possible if the 1) the total volume changes the static level, and 2) if there are other forces at play like pressure variables. IE., a boat will displace the same amount of water whether its sitting in a pond or sitting in the ocean.

You could cut a large hole in the stock metal diff cover, making sure to remain below the stock fill height, and then weld on a drum barrel extending outwards toward the back of the truck. Fill with the amount of fluid needed to bring the appropriate fill height to normal and during operation the R&P will only pick up what oil is within its proximity of cling. The remaining volume of oil cant bombard the carrier with additional fluid unless the static height was higher or unless its being pumped onto the carrier. Think of a manometer...

No. Only if all the extra oil is below the Operating level does that work. If any of the extra oil is above the operating level, then the extra oil will want to flow into the area where the operating level is the lowest causing it to go up. If the level is up to the carrier then the carrier will be flinging oil.

I totally understand what you're trying to say but...I still dont agree. Yes, forcing a carrier to churn through more oil will consume more energy and create more heat, but my own test results proved that this isnt the case with adding a larger volume diff cover.

Maybe. Either the flat back cover with the extra oil does not fling more oil around (what you seem to say is proven by your temps) OR it does and the extra heat radiating surface of the cover gets rid of that heat and then some. After watching the videos, I'm going with the latter.

We might have to agree to disagree. It has been interesting to discuss what is going on in the rear diff. It brings up many questions I'd like to ask a differential designer, like is the clearance between the ring gear and the cover intentionally selected to maximize the amount of oil carried over the top, sort of how pump clearances are designed? How much oil typically goes out to the axle tubes? Etc, etc.

 

[AH64ID]

I can see where both of you are coming from.

Here's my thought on it... the operating level will vary based on speed, 10 mph will sling a lot less oil than 80 mph. That tells me that the specific operating level isn't as critical. It can, and will, greatly vary under normal operating conditions.

A larger volume but the same fluid depth will decrease the fluid depth less at speed, but that just means it's like it is when the R&P is turning slower so I don't think that it will cause any issues.



On my 05 I had a MH cover. I think it was a nice addition and I never had any issues, thou I didn't put an amazing amount of miles on it. What I can tell you is that I won't be repeating the mod on my 18 for 2 reasons. First, fluid changes were stupid expensive with 8 quarts of gear lube.. something I couldn't quantify a benefit from. Second, it cost a decent amount of fuel mileage in cooler weather. It would take me 30+ miles to warm everything up and have my mileage/load settle down to where it should be and if it was really cold and I wasn't towing it never did. At the end of the day the setup cost me more money than it saved.

I go back and forth on the OEM finned cover. I like it since the OE volume will warm up to operating temp quicker, but not sure I want the cooling all the time. However, I do a lot of slow speed towing in the 18-24K GCW range and think the fins might help as there is a lot of low speed torque being applied during those times. Then again, Ram sells a lot of these axles with higher GCWR's than I am running at without a finned cover.

I'll likely just stick to the stock smooth cover and regular fluid changes with a good fluid.


I do also think that Banks is all marketing and hype these days.. It's been many many years since they were a viable go-to option for anyone doing any research.

 

[KATOOM]

If only Gale wanted us all to know what he truly found out during all his "testing"...

 

[brods]

I can see where both of you are coming from.

Here's my thought on it... the operating level will vary based on speed, 10 mph will sling a lot less oil than 80 mph. That tells me that the specific operating level isn't as critical. It can, and will, greatly vary under normal operating conditions.

A larger volume but the same fluid depth will decrease the fluid depth less at speed, but that just means it's like it is when the R&P is turning slower so I don't think that it will cause any issues.

I would be very surprised if the operating level at highway speeds is higher than the bottom of the carrier. If that is correct then it does matter if an aftermarket cover raises the operating level.

I do also think that Banks is all marketing and hype these days.. It's been many many years since they were a viable go-to option for anyone doing any research.

Maybe, but it sounds like they did all the right tests (see the video below). “We’re going to be coming with the data…” Oops, must have forgotten that. And I'm dying to know how the max tow stock cover would have performed in those tests!



On a side note, I am really jealous of Ca since all the old test trucks in the videos look better underneath than my truck did after its first year in the rust belt. The center section on my truck is flaking apart, so much so I had to weld up a leak! What the heck did AAM use to make these axles?

 

[KATOOM]

I would be very surprised if the operating level at highway speeds is higher than the bottom of the carrier. If that is correct then it does matter if an aftermarket cover raises the operating level.

It sure would be fun to see some real world tests with different fill levels and different viscosity fluids. A clear cover would be interesting too but I think that at highway speeds there's so much going on in there that we wouldnt see much of anything other than a wall of fluid.

On a side note, I am really jealous of Ca since all the old test trucks in the videos look better underneath than my truck did after its first year in the rust belt.

Yes, it is nice... I love it out here in northern Ca. Amazing weather and beautiful geography and our cars last forever too as long as you dont leave them parked in the direct sun for too long. I just cant stand the politics and the politicians...
We've toyed with moving for years but I'm coming to the conclusion that there is no "utopia" out there.

 

[Cummins12V98]

I love that sign!!! Also the metal artwork there.

 

[Regcabguy]

I would be very surprised if the operating level at highway speeds is higher than the bottom of the carrier. If that is correct then it does matter if an aftermarket cover raises the operating level.


Maybe, but it sounds like they did all the right tests (see the video below). “We’re going to be coming with the data…” Oops, must have forgotten that. And I'm dying to know how the max tow stock cover would have performed in those tests!



On a side note, I am really jealous of Ca since all the old test trucks in the videos look better underneath than my truck did after its first year in the rust belt. The center section on my truck is flaking apart, so much so I had to weld up a leak! What the heck did AAM use to make these axles?

It sure would be fun to see some real world tests with different fill levels and different viscosity fluids. A clear cover would be interesting too but I think that at highway speeds there's so much going on in there that we wouldnt see much of anything other than a wall of fluid.



Yes, it is nice... I love it out here in northern Ca. Amazing weather and beautiful geography and our cars last forever too as long as you dont leave them parked in the direct sun for too long. I just cant stand the politics and the politicians...
We've toyed with moving for years but I'm coming to the conclusion that there is no "utopia" out there.

Yeah,it's nice up there. Chronic central. I'm in San Diego which like all cities gets busy. I'm retired so we can navigate the traffic. I was born close to the ocean and with perfect weather so while nice to get away it's nice to return. We've gone up the coast from Malibu to Washington state.. Breathtaking. The politics do drive me crazy. The Dems have never seen a tax they don't like. Newsome's recent allocation of $70+ million for illegals irks me with so many legal residents really hurting. Private charities(are you listening Hollywood?) can handle the illegals which have legitimate needs but not on the backs of taxpayers.

 

[Joseph Donnelly]

If you read my column in the magazine, you know I did some back-to-back testing and found about 25 degrees lower temperatures with the Mag-Hytec unpainted cover vs. the stock cover. Next, I will re-install the Mag-Hytec with LE 1605 lube to compare with the Mobil 1 75-140 that I put in back when I was concerned that if a warranty issue arose, the lube would look like the stock stuff (un-dyed). From the old days I found that LE was a superior lube; LE 607 was the only stuff that prevented scuffing of Ford 9" pro gears in my racer.

 

[KATOOM]

Joseph Donnelly, interesting find but why were you worried about warranty issues? I have no interest in turning this thread into an oil argument for the masses but I was just curious as to where a warranty says you must use a certain brand.

 

[Regcabguy]

If you read my column in the magazine, you know I did some back-to-back testing and found about 25 degrees lower temperatures with the Mag-Hytec unpainted cover vs. the stock cover. Next, I will re-install the Mag-Hytec with LE 1605 lube to compare with the Mobil 1 75-140 that I put in back when I was concerned that if a warranty issue arose, the lube would look like the stock stuff (un-dyed). From the old days I found that LE was a superior lube; LE 607 was the only stuff that prevented scuffing of Ford 9" pro gears in my racer.

The 75-140 was necessary for towing or carrying a slide in camper?

 

[Joseph Donnelly]

I just wanted the lube to look like factory stuff in case I had to use the warranty. I didn't want to argue with a dealer who might blame the lube for something else. Various sources suggested 75-140 for towing, so I used it. If you want that heat-conductive aluminum cover to carry away heat from the oil, the oil needs to contact the cover, not just run around the ring gear. Banks is adding fins inside to give more contact between lube and aluminum. Mag-Hytec does that naturally, with a cover that catches the lube coming off the ring gear, and spreads it over the cover surface. The factory cover shape is largely designed to save diff space so less lube is needed to get a sufficient height to ensure lubing the pinion and side bearings. Look at some rears with removable center sections. Often the back side is not so sculptured as removable covers.

 

[brods]

Yes blasting lube everywhere will increase cooling. In heat exchangers the velocity of the fluid flow is intentionally kept high to scrub away the boundary layer of cooler fluid clinging to the heat exchanging surface....and that takes energy. Remember you cannot have it both ways with the flat back cover: either more oil is being flung around or less oil is being carried over the ring gear to the pinion bearings.

As for the rear ends with removable center sections, if there are modern designs, say within the last 10 or 15 years, they would be worth looking at. Ancient designs, like the Ford 9" rear have less merit as an example.

I wonder if the TransEngineer could weigh in on how managed the differential oil flows are? Maybe he knows some authority that could?

Since we’re going to go round and round at this point, I’ll leave it at this: Most everything Banks says about the oil management in the rear diff makes perfect sense. Unfortunately, without all his data, it can be debated how much any aspect really matters. Rear ends, both stock and those with the flat back covers, are not constantly failing. And given the lack of failures this seems like just another non problem being "fixed" by an aftermarket part. When you factor in the cost of the cover, the extra lube at each change and the small, but constant MPG penalty, the true cost of a cover with extra oil capacity is quite high. If it is worth it is anybody's guess at this point.

Fun reading if you have time to kill, lol. https://spiral.imperial.ac.uk/bitstream/10044/1/12896/1/Kolekar-AS-2013-PhD-Thesis.pdf

I did a quick look over of the document and this popped out.

Power losses due to churning effects can be as much as three times the combined losses due to sliding friction, rolling friction and windage at lower power and higher speeds.

YMMV

 

[KATOOM]

brods, thats a great find...! I'm reading through it right now and there's a lot of information. Funny though because as any research paper tends to be like, its basically saying that there are a ton of variables and everything depends on everything else.
Example - "that churning power loss has a weak or no dependence on lubricant viscosity" Not what I expected to read...

What we really need is for one of you guys out there to run a back to back comparison with the Ram AAM aluminum cover and then a Maghytec cover, using a gauge in the cab, so we can see if there's really any difference in the two designs. That would answer a lot of these questions...