Do Diff Covers Work Or Are They Just Bling?

[02SE]

Originally Posted by 2015_PSD

Well, correlation != causation. There are far too many of these covers out there being used in many different circumstances that if this were a widespread issue Internet amplification would certainly spread the bad news like wildfire.



Or the use for most owners isn't severe enough, that the poor design of the flat-backed covers hasn't yet resulted in early failure. Or they don't realize the cause of the early diff failure, and thus don't blame the poorly designed flat-backed diff covers.

It is what it is. My friends and many of their friends who arguably use and abuse their Dually pickups far more than most owners, towing large heavy trailers all over the country following the racing tour, were having regular failures of the rear diff, specifically the pinion bearings.

They saw these Banks videos when they hit Youtube last year, and recognized a poor design, which ALL of the guys who had experienced pinion bearing failure, were using at the time.

They switched out their flat-backed diff covers on their rebuilt rear diffs, and low and behold a full season of racing, with no more diff failures...

I only heard about this because I was talking to one of my friends who runs in a sportsman class, and tows a large, heavy goose neck race trailer with his Dually pickup. Then he related the story of numerous other friends in the Sportsman classes with the same experience.

Bottom line: If you aren't using and abusing your pickup truck like these racers, you might not have a problem for awhile. But they and Banks with his videos pretty clearly demonstrated the limitations and consequences of the flat-backed diff cover design.

I should also add that none of them bought the new Banks diff cover, as it wasn't on the market when they rebuilt their diffs the last time.

 

[CarbonSteel]

...

 

[userfriendly]

I'm with 02SE on this one.

My observation;
The guys who bought flat back covers are discounting Banks's experiments and solution.
Mad obviously, because they got suckered.

 

[meep]

For heavy towing, I'd be more interested in buying an oe-shaped cover with a temp sender bung in addition to dedicated drain/fill ports.

 

[hatt]

Originally Posted by SavagePatch
Originally Posted by 4WD
This is a decent design



Looks appealing. Have a link?

Even if Banks make a diff cover for my 2015 Ram 1500 I'm not sure if I would spend the $350. But definitely won't ever install a flat-back. Would rather stick with good gear oil and a sensible OCI.

(Love how he calls the guys at Mag-Hytec A$$-Hats!)

There are millions of good rear ends in the junkyard that never had any or only minimal maintenance. Changing the oil once with a top quality gear oil is probably a sensible OCI for most users.

 

[CarbonSteel]

Originally Posted by userfriendly
I'm with 02SE on this one.

My observation;
The guys who bought flat back covers are discounting Banks's experiments and solution.
Mad obviously, because they got suckered.

It would seem the "suckering" happened in both directions if one is willing to take Banks' glorified sales pitch as anything other than that. It was hardly objective, quantifiable, or third-party validated—let us not forget the primary reason for his "experiment" was to introduce his new and improved cover. 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 at least three axles (real testing requires a much larger test base—but I would give him more credit had he at least used 3 axles in the same vehicles) 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 at a minimum 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? How about both compared to Banks' 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? Where are the teardowns which show increased wear or excessive temperatures?

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? Were are the objective, third party test results to qualify his claims?

b. Were the test results compared against OEM design and conditions?

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


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?

c. Were multiple operating conditions encountered over long periods of time/miles to ensure the results were repeatable and not a one-off?

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.

 

[02SE]

You can do or believe whatever you want. I simply relayed the experience of numerous people who were towing heavy all over the country, and having regular differential failures, specifically the pinion bearings.

They saw those Banks videos, realized the pinion being starved for oil by the poor design of their Mag-Hytec covers, just might indeed be the problem. So differentials rebuilt and the Mag-Hytec covers removed, and lo and behold a full season of racing with no more diff failures. Whereas before it was a rebuild once maybe twice per season.

The people I'm referring to all rebuilt their diffs the last time, before Banks came out with his cover.

Sure Banks obviously had an ulterior motive in making those videos, as it showed how inferior those flat-backed covers are, and became a marketing tool for his own diff cover.

I know it's not what you want to hear, but I can tell you there are numerous racers who benefitted from those videos, who did not buy a Banks cover.

 

[CarbonSteel]

Originally Posted by 02SE
You can do or believe whatever you want. I simply relayed the experience of numerous people who were towing heavy all over the country, and having regular differential failures, specifically the pinion bearings.

They saw those Banks videos, realized the pinion being starved for oil by the poor design of their Mag-Hytec covers, just might indeed be the problem. So differentials rebuilt and the Mag-Hytec covers removed, and lo and behold a full season of racing with no more diff failures. Whereas before it was a rebuild once maybe twice per season.

The people I'm referring to all rebuilt their diffs the last time, before Banks came out with his cover.

Sure Banks obviously had an ulterior motive in making those videos, as it showed how inferior those flat-backed covers are, and became a marketing tool for his own diff cover.

I know it's not what you want to hear, but I can tell you there are numerous racers who benefitted from those videos, who did not buy a Banks cover.

As you said, it is what it is, but I have my own experiences towing heavy with a Mag-Hytec and I had zero problems and the UOAs were perfect--158,000 miles in one truck and 70,000 in the other. With that said, neither mine not your friends experiences prove anything just as Banks' does not either. All of it is anecdotal at best.