Differential Cover, Which one is better?

AnnDee4444

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Anything provided by an OEM is typically balanced by three things:

1. Cost/profit

2. Service life

3. (and to a far lesser degree) Customer satisfaction

Based upon my experience in owning dozens of cars, I can easily attest which one trumps the remainder—profit. OEMs typically will not do anything more than meets a minimum threshold (whatever that is)…period. With that said, OEMs have installed increased capacity covers on some applications such as heavy duty trucks and the like.

My “horse” in this race has to do with the claims/suggestions that Banks makes without the objective, repeatable, third-party verified data as well as testing methodology to support them. A secondary issue is his overall opinion that flat back covers are “bad or add no value”. The reason that he is doing this is obvious—to state that his cover is “better”. Had he not produced a new cover, then his claims would have been objective versus a glorified sales pitch and this is why I say he is a great salesman—a few YT videos and taadaa, flat back covers are bad and Banks covers are good!

His premise and data would have been much more objective and valid had he used three axles in a controlled test for say 100,000 miles with about 25-50% of those miles towing and NOT a simulated test on a lift. The test components should consist of a:

1. Factory OEM axle

2. Factory OEM axle with a flat back cover

3. Factory OEM axle with a Banks cover


For example, (and I am paraphrasing so keep me honest), he states (and all of these infer or suggestion a detrimental or negative situation in some way):

1. Flat back covers over work the fluid and cause excessive aeration.​

a. OK. Based upon what? A flashlight shined into the back of a Banks modified Mag-Hytec cover? There are incredible shearing forces at work within a differential and “working the fluid” happens regardless of cover design or fluid levels, after all, the ring gear is partially submerged in oil at all times.

b. If the fluid is overworked, then we can surmise that it leads to loss of viscosity or some other negative result. Where are the test results to show that viscosity loss occurred? Were they compared against factory OEM results?​

2. Flat back covers impede or interrupt fluid flow (or flow is not "optimal") over the ring gears.​

a. OK. Were temperature tests performed on the pinion gear in operation to determine that lubrication was insufficient? Were they compared against OEM results?

b. What about ring and pinion gear wear results?

c. What about viscosity results? Was the fluid overheated by the pinion gear that allegedly receives less lubrication due to the flat back design?​

3. Flat back covers increase the volume of fluid and this is not optimal for the bearings.​

a. OK. Were the bearings inspected and measured at zero miles and then again after the test?

b. Were they compared against OEM design and conditions?

c. Were temperature tests performed on the bearings and compared against OEM?

d. Did the increase of fluid also increase the service life of the fluid or the assembly in some way?​

4. Flat back (finned) covers do not improve temperatures.​

a. OK. Were the flat back temperatures compared against OEM temperatures in various operational conditions?

b. Were the tests performed with actual temperature sensors at critical points of the assembly versus pointing an infrared temperature gun at the housing?​

As I said before, without a certified testing methodology and a proper baseline set, all of these “tests” were nothing more than a glorified sales pitch for his new and improved axle cover. I have seen nothing since then to change my mind, but I am totally open to "eating crow" should the data present itself to substantiate his claims.
Interesting. So what would you recommend for a Jeep? One of the reasons I liked the ARB cover was from the increased clearance, and it obviously doesn't add capacity. Would any of this really be an issue with stock sized tires?
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twisty

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Anything provided by an OEM is typically balanced by three things:

1. Cost/profit

2. Service life

3. (and to a far lesser degree) Customer satisfaction

Based upon my experience in owning dozens of cars, I can easily attest which one trumps the remainder—profit. OEMs typically will not do anything more than meets a minimum threshold (whatever that is)…period. With that said, OEMs have installed increased capacity covers on some applications such as heavy duty trucks and the like.

My “horse” in this race has to do with the claims/suggestions that Banks makes without the objective, repeatable, third-party verified data as well as testing methodology to support them. A secondary issue is his overall opinion that flat back covers are “bad or add no value”. The reason that he is doing this is obvious—to state that his cover is “better”. Had he not produced a new cover, then his claims would have been objective versus a glorified sales pitch and this is why I say he is a great salesman—a few YT videos and taadaa, flat back covers are bad and Banks covers are good!

His premise and data would have been much more objective and valid had he used three axles in a controlled test for say 100,000 miles with about 25-50% of those miles towing and NOT a simulated test on a lift. The test components should consist of a:

1. Factory OEM axle

2. Factory OEM axle with a flat back cover

3. Factory OEM axle with a Banks cover


For example, (and I am paraphrasing so keep me honest), he states (and all of these infer or suggestion a detrimental or negative situation in some way):

1. Flat back covers over work the fluid and cause excessive aeration.​

a. OK. Based upon what? A flashlight shined into the back of a Banks modified Mag-Hytec cover? There are incredible shearing forces at work within a differential and “working the fluid” happens regardless of cover design or fluid levels, after all, the ring gear is partially submerged in oil at all times.

b. If the fluid is overworked, then we can surmise that it leads to loss of viscosity or some other negative result. Where are the test results to show that viscosity loss occurred? Were they compared against factory OEM results?​

2. Flat back covers impede or interrupt fluid flow (or flow is not "optimal") over the ring gears.​

a. OK. Were temperature tests performed on the pinion gear in operation to determine that lubrication was insufficient? Were they compared against OEM results?

b. What about ring and pinion gear wear results?

c. What about viscosity results? Was the fluid overheated by the pinion gear that allegedly receives less lubrication due to the flat back design?​

3. Flat back covers increase the volume of fluid and this is not optimal for the bearings.​

a. OK. Were the bearings inspected and measured at zero miles and then again after the test?

b. Were they compared against OEM design and conditions?

c. Were temperature tests performed on the bearings and compared against OEM?

d. Did the increase of fluid also increase the service life of the fluid or the assembly in some way?​

4. Flat back (finned) covers do not improve temperatures.​

a. OK. Were the flat back temperatures compared against OEM temperatures in various operational conditions?

b. Were the tests performed with actual temperature sensors at critical points of the assembly versus pointing an infrared temperature gun at the housing?​

As I said before, without a certified testing methodology and a proper baseline set, all of these “tests” were nothing more than a glorified sales pitch for his new and improved axle cover. I have seen nothing since then to change my mind, but I am totally open to "eating crow" should the data present itself to substantiate his claims.
Would a proper test be past results? Is there a slew of aftermarket diff covers having a higher component failure rate?
 

CarbonSteel

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Interesting. So what would you recommend for a Jeep? One of the reasons I liked the ARB cover was from the increased clearance, and it obviously doesn't add capacity. Would any of this really be an issue with stock sized tires?
Since there are no extra capacity covers that I have found yet for a M220 axle, I would go for the toughest one that I could find if your individual operating conditions require it. The ARB is one of the nicer OEM capacity covers as is the Spicer models. I also like MetalCloak and Next Venture. I added temperature bosses into my OEM covers to install temp gauges, but this is an interim step to set a baseline. I will eventually change them to one of the aforementioned steel covers and add temp bosses to them.

The overall issue that I see with such a low capacity axle is heat and shearing. I was very surprised to see only 1.5QTs of fluid in the rear axle. I just received the UOA results for my first OC on the axle (I will post soon) and the iron is the highest I have ever seen in any axle that I have owned--especially considering that I dumped it at 5K miles. Needless to say, I will not be doing long OCs on these axles, particularly if the next UOA comes back with high iron like this one did.
 

CarbonSteel

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Would a proper test be past results? Is there a slew of aftermarket diff covers having a higher component failure rate?
They can help set a trend or a baseline, but like my test results from the past and for that matter, Banks' to a large degree, they would be anecdotal. With that said, in the absence of controlled test results, anecdotal data is better than none or opinion based data.

To my knowledge, I have not heard of a single axle failure that was attributed to an aftermarket axle cover. I have seen them fail from too high of a load, failure to change the fluid, using the wrong fluid, or just plain abuse.
 

CarbonSteel

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So is the Yukon cover any good? lol I got mine free with new gears so maybe there is a reason. ;)
It mimics the OEM design and seems to be well built from nodular iron--it would have been good to see the internals and I searched for a photo, but did not find one. The extra plug to fill the oil is nice versus using the same hole to fill and check the level. I would run it with no issues.
 
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AeonFrost

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wow those looks amazing! I would totally paint it my self too, and its steel. Yup its done I'm getting these bad boys. Thank you
 
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AeonFrost

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I bought the Metal Cloak. Mostly because I wanted a decent diff skid plate, front and rear. The metal cloak diff cover is cast iron, weighs a #$&@ ton. It’s like the Chuck Norris of diff covers.l If I accidentally back up into a rock, I feel sorry for the rock.

the skid plate for the rear will fit a range of diff covers but the skid plate for the front diff will only fit the Metal Cloak diff cover.

so that is what I bought. Price was 330ish for both covers and skid plates. Only bummer is I have to paint the diff cover as they come unfinished.
An you provide a link to where you bought them?
 

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twisty

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They can help set a trend or a baseline, but like my test results from the past and for that matter, Banks' to a large degree, they would be anecdotal. With that said, in the absence of controlled test results, anecdotal data is better than none or opinion based data.

To my knowledge, I have not heard of a single axle failure that was attributed to an aftermarket axle cover. I have seen them fail from too high of a load, failure to change the fluid, using the wrong fluid, or just plain abuse.
I agree a controlled test would be best but in the real world there just doesnt seem to be a problem with any covers other then ones that wont take a hit from a rock or whatever. Nothing to worry about folks.
 

azrubi

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Wranglerjake

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https://www.cjponyparts.com/afe-rea...a-m220-jeep-wrangler-jl-2018-2019/p/4671000R/

this is almost twice the price as this, from review and description it seems like both hold larger amount of oil compare to stock, but which one is better?

https://www.amazon.com/Yukon-Gear-Y...NBMNGFM1A4B&psc=1&refRID=P100ZNX8RNBMNGFM1A4B

please help
take a look at these. They’re cast iron with a lifetime warranty. Can’t go wrong. Have one for my jk. Not sure if the bolt pattern would be different for the JL or not... https://completeoffroad.com/i-23896837-trail-defense-dana-44-differential-cover-cast-iron-td44a.html
 

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Great info , after reading this thread. Decided on keeping the stock covers and adding the Rancho guide plates.
I was going to go with the Rancho but saw a post where the front cover was bent pretty good after a hit. That prompted me to research a few others and the Metal Cloak seemed the best, even if you’re stuck with their front diff cover in order to use their front skid plate. They are serious pieces of kit. I painted mine textured black, and waiting on a free day to install and will post pix. I ended up getting the skid plates powder coated to match the covers and because I had a bunch of other parts to coat so adding these was cheap.
 

Hudson

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I had the Metal Cloak diff skid plates powder coated black because the zinc finish is too shiny, and I spray painted the diff covers textured black. Installed today, rear was a piece of cake and front slightly less easy as the top four bolts are somewhat harder to get to given the track bar being in the way.

I am very impressed by their quality. The diff covers are impressively thick. Again, I feel sorry for the rock that hits them.

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