Do Diff Covers Work Or Are They Just Bling?

[DoubleWasp]

I don't take it to mean that box diff covers will destroy an axle. I think the greater point is that they aren't offering anything "extra" for the money, and that claims of such are pretty much marketing.

Having a drain plug and a dipstick sure would make my life easier, but since the factory AAM finned cover is cheaper, and obviously allows the axle to live under ridiculous stresses, I pulled the trigger there. I also happen to have little doubt that a cover made by AAM, in-house, for the axle they engineered from scratch, is the best cover on the market.

At the end of the day, my truck has been living for hundreds of thousands of miles with the factory stamped steel cover, so even doing nothing would not be a "killer", but anything I can do to help, I will do.

 

[ofelas]

Personally, I'd slap a Banks decal on that AAM diff cover.

 

[CarbonSteel]

Originally Posted by hatt
Because your diff hasn't blown apart doesn't mean the aftermarket cover is offering longevity benefits or even as good as OEM. That sounds like the xW-20 guys.
So a 10 minute YouTube video trumps 5 years of actual use? OK, I stand corrected.

 

[hatt]

Originally Posted by 2015_PSD
Originally Posted by hatt
Because your diff hasn't blown apart doesn't mean the aftermarket cover is offering longevity benefits or even as good as OEM. That sounds like the xW-20 guys.
So a 10 minute YouTube video trumps 5 years of actual use? OK, I stand corrected.

Plenty of people did your same feat with the stamped cover and factory fill.

It's also not a 10 minute video. He's doing extensive testing. We don't know the results but I doubt he's making new videos making a fool of himself after much of the testing has been done.

I think we get too emotionally involved sometimes. Our personal preferences might be shenanigans. I sold two cases of M1 5w-30 to my brother for cheap(what I had in it) because it wasn't 10w-30.

 

[thescreensavers]

Id say it looks like the flat back covers are detrimental but, these heavy duty axles(and others axles in vehicles) are so over built, that even at 150k miles with using a bad cover you likely wouldn't see a failure. When Banks has his Part 3 with some data maybe it can be quantified.

 

[CarbonSteel]

Originally Posted by hatt
Originally Posted by 2015_PSD
Originally Posted by hatt
Because your diff hasn't blown apart doesn't mean the aftermarket cover is offering longevity benefits or even as good as OEM. That sounds like the xW-20 guys.
So a 10 minute YouTube video trumps 5 years of actual use? OK, I stand corrected.

Plenty of people did your same feat with the stamped cover and factory fill.

It's also not a10 minute video. He's doing extension testing. We don't know the results but I doubt he's making new videos making a fool of himself after much of the testing has been done.

I think we get too emotionally involved sometimes. Our personal preferences might be shenanigans. I sold two cases of M1 5w-30 to my brother for cheap(what I had in it) because it wasn't 10w-30.
This is not emotional for me, but logically what Banks is suggesting (pinion gear not being lubed for example) is baloney.

 

[hatt]

I agree he's a little out there on the pinion bearings. The extra capacity and inferior flow does look to substantially increase drag on the diff and needlessly work the fluid. The prior video shows the oil level drops a lot in a standard cap cover. Sump>ring gear>around the case to the pinion>sump.

 

[thescreensavers]

Saying pinon bearing isn't getting any lube at all is not correct. I think what he means is that it is not receiving as much lube as the OEM diff cover.

The OEM Diff cover does set up a favorable condition which allows more fluid to be thrown at the pinion. We can agree on that but, maybe even with the flat cover the pinion is still receiving enough lube?


Now we just need a side view

 

[hatt]

I think more oil going to the pinion/bearings is more beneficial than more oil being beat on by the bottom of the ring gear or carrier. Obviously that has no benefits.

 

[DoubleWasp]

To be fair, he never says that using a flat back cover is going to cause a mechanical failure. He expresses concerns about the pinion and bearings. He demonstrates a clear reduction of oil flow to the forward section of the diff. He demonstrates an overworking and excess turbulence of the fluid.

The video does not prove mechanical failure. It does prove that flat back covers aren't living up to their claims of improving anything for the diff. The only thing left to find out is if it runs any cooler. It sure isn't helping anything where lubrication is concerned. It's doing the opposite.

I was just looking through bunches of pics of axle housings used for racing, and I'm not seeing big box covers. Seeings lots of close-fitting covers. The man might be going a little off the deep end worrying about pinion and bearing harm, but he's definitely barking up the right tree in attempting to prove big diff covers don't help rear ends.

 

[CarbonSteel]

Originally Posted by hatt
I agree he's a little out there on the pinion bearings. The extra capacity and inferior flow does look to substantially increase drag on the diff and needlessly work the fluid. The prior video shows the oil level drops a lot in a standard cap cover. Sump>ring gear>around the case to the pinion>sump.
This would need to be better defined. I could go along with that if there were facts to support it. For example, what constitutes "overworking the fluid" "increased drag" and how is that manifested/qualified? Let us not forget there are two gears turning at 90 degrees to one another--there is a considerable shearing force happening. If the Mag-Hytec is contributing to "overworking the fluid" it certainly has not shown up in a major viscosity decrease or increase. Amsoil SVO (75W-140) gear oil has a virgin viscosity of 26.35 (cSt @100C) and after 80K miles it was 24.31 in my FX4. His "findings" will be interesting to say the least and what will be more interesting will be the responses from the axle cover manufacturers.

 

[IndyFan]

Originally Posted by 2015_PSD
Originally Posted by hatt
I'm pretty sure Banks already knows the test results will back up his thinking. He didn't do all this to post the results: "oh yeah I was totally wrong in those four videos I posted."
The ultimate question is what is he going to prove? If "flat back" covers were so detrimental to axle longevity (if that is his point and it seems to be based upon his stating they do not lubricate the front pinion bearing adequately), with the internet amplification that happens today, this would be a widely known issue. I can only speak to my own experience and it does not match his in the slightest. I am certain that if Mag-Hytec covers were SO bad that I would have destroyed my axle with the towing that I did--but that did not happen. Not sure what he is trying to prove, but I am not sure that he is going to prove anything.


You are drawing more conclusions than he's actually offering. Sit back and wait and see what he does next. I think it is pretty clear that the flat back is working the fluid more than the OEM. How much has not yet been determined, but that noise is certainly not a great thing. As for what's happening at the pinion, we don't know for sure unless we can see it. I think the jury is out on that part of it.

 

[IndyFan]

Originally Posted by 2015_PSD
This is not emotional for me, but logically what Banks is suggesting (pinion gear not being lubed for example) is baloney.


Lol, ok, not an emotional issue for you? Sure looks like it is.

 

[clinebarger]

Originally Posted by 2015_PSD
But logically what Banks is suggesting (pinion gear not being lubed for example) is baloney.


I would have to agree with your stance on this.....The Ring Gear itself will carry lube to the Pinion Head & the interface between the Ring Gear & Pinion Gear.

What would be interesting.......Installing a temp probe between the 2 pinion Bearings as the lube channel that he theorizes is being compromised is for the Pinion Bearings NOT the Pinion Head.

*Red arrow is where I would install the temp probe (Right into the "bath" for the 2 pinion bearings.
*Yellow arrow is the lube channel feed for the pinion bearings.
*Green arrow is the return channel "spill over" back to the sump.

 

[CarbonSteel]

Originally Posted by IndyFan
Originally Posted by 2015_PSD
This is not emotional for me, but logically what Banks is suggesting (pinion gear not being lubed for example) is baloney.
Lol, ok, not an emotional issue for you? Sure looks like it is.
I have stated nothing but facts and backed it up with data--which is more than what has been shown in the videos.

 

[DoubleWasp]

The close fitting cover sure looks like it slings a lot more oil toward the area with the yellow arrow though.

 

[DoubleWasp]

This seems to have been a possible motivator for Banks' video:

https://www.youtube.com/watch?v=vAoyfoRp6k0

 

[DoubleWasp]

Here's a video that sheds a lot of light on how an actual axle manufacturer feels about the flow of lube inside of an axle housing:

https://www.youtube.com/watch?v=Q99iG3yMwL4

 

[cronk]

Originally Posted by 2015_PSD
Originally Posted by IndyFan
Originally Posted by 2015_PSD
This is not emotional for me, but logically what Banks is suggesting (pinion gear not being lubed for example) is baloney.
Lol, ok, not an emotional issue for you? Sure looks like it is.
I have stated nothing but facts and backed it up with data--which is more than what has been shown in the videos.


To be fair, you really haven't posted facts and data, just an anecdotal experience with an aftermarket cover.

I have an F350 With 170k miles with the stock stamped cover, and no issues. Done plenty of towing.

You can clearly see in the video that the higher fluid level causes the "paddling" by the carrier, and there is a lot of fluid churning off in directions that aren't helpful to anything.

I'll keep an open mind, and await the final testing.

 

[CarbonSteel]

Originally Posted by cronk
Originally Posted by 2015_PSD
Originally Posted by IndyFan
Originally Posted by 2015_PSD
This is not emotional for me, but logically what Banks is suggesting (pinion gear not being lubed for example) is baloney.
Lol, ok, not an emotional issue for you? Sure looks like it is.
I have stated nothing but facts and backed it up with data--which is more than what has been shown in the videos.


To be fair, you really haven't posted facts and data, just an anecdotal experience with an aftermarket cover.

I have an F350 With 170k miles with the stock stamped cover, and no issues. Done plenty of towing.

You can clearly see in the video that the higher fluid level causes the "paddling" by the carrier, and there is a lot of fluid churning off in directions that aren't helpful to anything.

I'll keep an open mind, and await the final testing.
The same can be seen in the clear OEM cover. All of the hoopla about aeration and the heat that it generates is just that. The same amount of aeration exists with the OEM cover. He talks about viscosity issues with a flat back cover but the UOAs that I have done do not support his statements nor does all of his talk about the pinion gear starving for oil due to the flow of the oil, but hey 10 minutes on jack stands proves everything.

My guess is all of the "testing" by Banks is a pre-cursor sales pitch for his new and improved cover, but what do I know...