What aftermarket diff cover guys don't tell you!

Aftermarket rear differential covers have been around for decades. But what effect do they have on your gear oil? What's really going on behind the cover? Gale Banks compares popular high-capacity flat-back units with the new patented Ram-Air rear diff cover for Ford Sterling axles.

The new Ram-Air rear differential cover fits the 1985-2020 Ford Sterling Axle 12-bolt with 10.25/10.5 ring gear and is available with Amsoil SEVERE GEAR® Synthetic Extreme Pressure Gear Lube.

Available for:
2001-2019 Chevy/GMC and 2003-2018 RAM with AAM 11.5" or 11.8" 14-bolt rear axle
1985-2022 Ford Sterling Axle 12-bolt with 10.25"/10.5" ring gear
2017+ Ford F250 HD tow pkg and F350 SRW with Dana M275 axle
2019+ RAM 2500/3500, 2020+ GM 2500/3500 with 14-bolt AAM axle, 11.5", 12" ring gear

Watch the full "Behind the Diff Cover" video series.

00:00 Intro
00:22 Visual comparison
01:14 Making a clear diff cover
01:40 Analyzing fluid flow with factory fill
05:26 Analyzing fluid flow with overfill level
07:55 Dyno testing fluid temps
08:30 Lack of airflow
09:39 On-road testing
10:27 Test results
11:31 Ram-Air cover explained

Protected by AMSOIL, the leader in synthetics.

#differentialcover #diffcover #engineering

[davestaco]

The glass actually improves the oil flow. It eliminates the horizontal fins that were cast inside.

[-DC-]

It's almost like the OEM'S actually know what they are doing 🤣, who'd a thunk it 🤷. Great video.

[zxr]

I want to see the fluid flow through transparent versions of the Banks and stock.

[brian_dc]

oem always knows best! thanks Banks for being one of those companies that go out of the way for proper R&D for a functioning product, and going the extra mile to show your findings to the community! You guys found yourselves another customer!

[bobocaterpillar]

so... he said the ideal temp was 200 or below the STOCK cover kept the oil about 195 during the uphill test....
sounds good enough to me!

this guy is a genius... he just SOLD me on the stock cover that is already on my truck! SOLD!!!

[precisiondiesel]

This man is a legend. Not many manufacturers do the intense, real world, common sense rnd, like Banks.

[asherdie]

When do we get to see a clear version of the Banks cover in operation?

[Dogslovetrucks]

OR... you could just keep a stock cover and change the lube at recommended intervals

[whiteymccluck]

I started off thinking I was watching a mechanic show what not to do. Only in the last couple minutes did I realize it’s a 13 minute commercial for his patented diff cover.

[nateross]

A couple things to consider.... First, you don't need oil dumping on the ring and pinion gears contact point. You only need a tiny bit of oil between steel on steel contact points for lubrication. As long as the steel doesn't go dry, your fine. Just the ring gear dragging through the oil is sufficient lubrication for both the ring AND pinion. Second, you don't need oil dumping on top of the bearings either, you just need the bottom portion of ths bearings submerged in oil and then the rotating bearings will drag oil up around the rest of the bearing. So as long as your oil level is high enough it doesnt matter what the splash pattern inside the diff is. We're dealing with heat hardened bearings and gears, heat buildup is a non issue. I've never seen smoking oil coming out of a properly functioning diff. Air in the fluid and heating up is a sales gimmick. If heat buildup was a danger you'd see smoke pouring out the breather tube from burning oil. It doesn't. Aftermarket diff covers are a gimmick. Keeping your diff oil at the proper level, and change it a proper intervals is the only thing you need to do to your diffs.

[doctordifferentialspeedsho]

This information is absolutely gold. I can not begin to tell you how many aftermarket covers have caused gear failures. Actually we will not offer a warranty on a diff with an aftermarket cover. I’ve been saying for years they don’t offer a single benefit. I own a shop that we build differentials daily. Please let me know how to begin selling your products as a dealer!! We will sell a bunch.

[JordanTheMann]

First he tells me aftermarket diff covers are a scam and then he tries to sell me one 😂

[techbilly]

How about making a clear version of the banks cover, so we get to see how it flows... A REAL side by side comparison.

[donaldb]

This is a total "Parlor Trick"! He should have a side show at the carnival!

[HondaRedneck]

This guy has so much beef with diff covers I love it

[HoosierDaddy_]

I can't get over having those horizontal fins on the inside of that flat back cover. I watched all of these previous videos and have to say I'm impressed with Banks commitment to find the true nature of diff fluid flow.

[sc_mastertech]

I love the engineering that went into your design. It all makes sense and is easy to understand. I also understand as a company why this has all been done on 3/4 and 1 ton trucks, but this would be equally useful for those of us with 1/2 ton trucks. I certainly don’t overload my 1/2 ton but would love to see this available for some popular smaller axles. Hope that becomes a reality, I’ll gladly step up and buy one.

[lakeschoolrestorationchann]

I like when companies call out other companies by name without bs. Seems like a solid product that works, what more can you ask for 👍🏻

[valis]

I am so glad I found this channel, I am always arguing people and saying "You know these things were designed by engineers that spent their entire life learning how to design machinery. Why do you think something a guy threw together in his garage is somehow better?" and everyone gets mad at me.

[williamscanlan]

I haven't priced out the Banks cover yet, but the time savings from having the drain plug (magnetic at that) is VERY valuable in my opinion. That would make changing the oil about a 10 minute project.