Flat Back Diff Cover - Failures 🤔

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Now that Banks has disproved the benefits of flat back differential covers ((Mag-Hytek) Check out his YouTube videos on the subject). I'm curious to know if anyone has ever had a failure due to a flat back diff cover. If they don't add any benefit other than being eye candy that's fine with me. Everyone should spend their money how they see fit and outfit their rigs however they want. But if they are doing damage should owners with flat back diff covers remove them? Or are the negative affects so small that if you already have one installed that you should just leave it be?
 

JHZR2

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Wait, so now a Mag Hytec cover can cause damage? Did I read that right? When I started servicing a diff for the first time, it was the issue that GM had covered up holes in the axle due to a diff cover gasket, and it was sure reduced life. I dont know if that's true... Id think that given the ease of making a diff cover out of clear stock, the matter of flow and circulation of lubricant with a flat back cover would have been long resolved. I have a Mag Hytec on my truck because I felt it did look better than stock, and because it had more capacity and a drain plug (stock required removing the cover, which is a mess). I just watched the banks video, and what he says does make sense. The aeration is the scary thing to me... But looking around at the multiple videos on this - some round back videos also aerate. So it looks like the only option is to buy Banks' solution smile I do think he did a good job with this, selling or not...
 
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It took me a lot longer than it should have to realise OP wasn't talking about flat black differential covers. lol
 
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So there is some information out there showing where the curve is used to direct oil flow as it goes up the back, pulled by the gear, and as it goes up and over, the curve flows it into passages down the axle tubes to feed the outer axle bearings. Plenty of folks run the flat back covers and there hasn't been to my knowledge a wave of failed diffs. Enough lube must make it through with those too. ? M
 
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Originally Posted by JHZR2
Wait, so now a Mag Hytec cover can cause damage? Did I read that right?
Per Banks, yes. But along with being a great researcher and developer he's also an amazing promoter. That's why I wanted the opinions and real world experiences of the members here.
 
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Banks did not prove or disprove anything. Where is the objective third party verified data to substantiate his claims? Answer-- there is none. He goes on and on and on about how flat back covers create aeration and increase heat. Two gears turning at 90° will generate aeration by themselves, there are incredible shearing forces at work in a differential that both works the fluid and creates tons of aeration. More than a few stock shaped clear covers on YouTube that show this in action. Had Banks not created a glorified sales pitch for his new and improved cover he would have a bit more believable. I towed 8-9K pounds with an F-150 in all manner of climates and conditions with a Mag-Hytec for about 70,000 of the 160,000 miles I drove it with zero issues. Color me not impressed with Banks' "findings".
 
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Originally Posted by Jethro_Bob
It took me a lot longer than it should have to realise OP wasn't talking about flat black differential covers. lol
🤣
 

JHZR2

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Originally Posted by 2015_PSD
Banks did not prove or disprove anything. Where is the objective third party verified data to substantiate his claims? Answer-- there is none. He goes on and on and on about how flat back covers create aeration and increase heat. Two gears turning at 90° will generate aeration by themselves, there are incredible shearing forces at work in a differential that both works the fluid and creates tons of aeration. More than a few stock shaped clear covers on YouTube that show this in action. Had Banks not created a glorified sales pitch for his new and improved cover he would have a bit more believable. I towed 8-9K pounds with an F-150 in all manner of climates and conditions with a Mag-Hytec for about 70,000 of the 160,000 miles I drove it with zero issues. Color me not impressed with Banks' "findings".
That's where Im at too. At first, I looked up the videos and saw the aeration... And thought this was an interesting finding. Then I saw another that showed a curved back that also aerated the lube. So... Since there are hundreds of millions of vehicles with curved back diffs, all living life of vehicle service, should I be concerned? I think the answer is no - aeration, as you indicate, is a thing. And unlike an AT, or an engine, it might not be a big concern in the lubrication of a diff - I suspect it necessarily is NOT a big concern, otherwise diffs wouldnt generally be considered to be bulletproof.
 
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Banks findings weren't that the flat backs cause failures, it's just that it causes excessive aeration of the gear oil which translates to lost fuel economy since you're wasting lots of energy whipping the fluid.
 
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Originally Posted by blufeb95
Banks findings weren't that the flat backs cause failures, it's just that it causes excessive aeration of the gear oil which translates to lost fuel economy since you're wasting lots of energy whipping the fluid.
I do not buy that either. Do we really think that oil being whipped in a differential has the ability to substantially impact fuel economy? Let us not forget we are talking about trucks where a head wind or your right foot would have much more impact than oil ever will.
 
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I work in industrial maintenance and handle many gear reducers of different types(dodge, hub city, us gear, etc) that run at input speeds equal to or greater than a differential. I'm not of the opinion that a flat cover will hurt anything. I have seen studies where they drop temperatures under certain applications and I think that outweighs the slight aeration issue.
 

4WD

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If flat back diffs made any sense … you would certainly see hundreds of them from OEM's of all shapes and sizes. But we don't … Dozens of brands … all domed and tight to the ring … Air entrainment means a percentage of oil is not available at the stress riser regardless of fluid capacity … so there is something to the standard shape of diff covers running tight to the ring and sending a concentration of lubricant to the concentration of stress … pinion, spiders, pins, etc … Splashing against the dumb stuff is what a flat back is good for …
 
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Originally Posted by 4WD
If flat back diffs made any sense … you would certainly see hundreds of them from OEM's of all shapes and sizes. But we don't … Dozens of brands … all domed and tight to the ring … Air entrainment means a percentage of oil is not available at the stress riser regardless of fluid capacity … so there is something to the standard shape of diff covers running tight to the ring and sending a concentration of lubricant to the concentration of stress … pinion, spiders, pins, etc … Splashing against the dumb stuff is what a flat back is good for …
Ok, so you're of the opinion that there's no benefit. But is there anything that shows that they do damage and lead to failures?
 
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Originally Posted by 2015_PSD
Originally Posted by blufeb95
Banks findings weren't that the flat backs cause failures, it's just that it causes excessive aeration of the gear oil which translates to lost fuel economy since you're wasting lots of energy whipping the fluid.
I do not buy that either. Do we really think that oil being whipped in a differential has the ability to substantially impact fuel economy? Let us not forget we are talking about trucks where a head wind or your right foot would have much more impact than oil ever will.
Ya, I'm sure my travel trailer is the biggest culprit to a drop in mpg.

20200613_081153.jpg
 
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Originally Posted by SavagePatch
Originally Posted by 4WD
If flat back diffs made any sense … you would certainly see hundreds of them from OEM's of all shapes and sizes. But we don't … Dozens of brands … all domed and tight to the ring … Air entrainment means a percentage of oil is not available at the stress riser regardless of fluid capacity … so there is something to the standard shape of diff covers running tight to the ring and sending a concentration of lubricant to the concentration of stress … pinion, spiders, pins, etc … Splashing against the dumb stuff is what a flat back is good for …
Ok, so you're of the opinion that there's no benefit. But is there anything that shows that they do damage and lead to failures?
You are not going to find data to support damage--far too many of them in use such that if they caused damage and with "Internet amplification", it would be everywhere. Bad news always travels faster than good...
 
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Originally Posted by SavagePatch
Originally Posted by 2015_PSD
Originally Posted by blufeb95
Banks findings weren't that the flat backs cause failures, it's just that it causes excessive aeration of the gear oil which translates to lost fuel economy since you're wasting lots of energy whipping the fluid.
I do not buy that either. Do we really think that oil being whipped in a differential has the ability to substantially impact fuel economy? Let us not forget we are talking about trucks where a head wind or your right foot would have much more impact than oil ever will.
Ya, I'm sure my travel trailer is the biggest culprit to a drop in mpg.
LOL - it was definitely mine!
 

4WD

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There are not enough out there for that data set … but I think Banks did as good as most at his demonstration … After sizing up what was being sold. (clear cover and instruments) … The only aftermarket aluminum I ever bought was G2 … and it was domed shaped … which is also a strong shape against impact …
 
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Originally Posted by SavagePatch
Now that Banks has disproved the benefits of flat back differential covers ((Mag-Hytek) Check out his YouTube videos on the subject). I'm curious to know if anyone has ever had a failure due to a flat back diff cover. If they don't add any benefit other than being eye candy that's fine with me. Everyone should spend their money how they see fit and outfit their rigs however they want. But if they are doing damage should owners with flat back diff covers remove them? Or are the negative affects so small that if you already have one installed that you should just leave it be?
Somewhere on here is a discussion about flat-back diff covers. I gave examples of several people I know who had issues to the point of failure using the fancy flat-back diff covers from several manufacturers. Now they were towing heavy, and a lot. Once they stopped using the flat-backed diff covers, they had no more issues.
 

4WD

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Originally Posted by Blkstanger
Banks is selling his new one for $400. That's what all the bashing is about.
He showed the development of the Banks unit and the main one in question is $300. $100 delta not here/there for a $75k 3500 doing HD towing. But diesel LT's are not the only high load rear ends … here is an OEM example from a high performance street car rear end. Note how it hugs the ring gear.

D9D4519F-EA51-4CEC-83F8-C6C17BDFDC54.png
 
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