Updated on August 11, 2026.
Disclosure: This is a paid partnership between SPELAB and @Brandon24v. He was compensated to install and feature the SPELAB differential cover in his video. His comments below are quoted from that sponsored video; no independent temperature testing or oil analysis was performed for this article.
YouTuber @Brandon24v Documents A Differential Cover Swap On His Tow Rig
If you own a heavy-duty truck, you know stock parts often have real limits, especially once you start towing seriously. That's the situation truck builder and YouTuber @Brandon24v documented with his 3rd Gen Cummins tow rig: he replaced the stock differential cover with a SPELAB aluminum differential cover and walked through what changed for him.
His take, in his own words: a worthwhile upgrade for maintenance convenience and expected cooling benefit. Here's what he covered, along with context on what's demonstrated versus what's a reasonable design expectation.
About the YouTuber: @Brandon24v
For those who don't know, @Brandon24v is a die-hard Cummins enthusiast and a master of monster truck builds. His channel is packed with hands-on content, from engine swaps and fuel system installs to creating some of the wildest lifted trucks on the platform. He isn't just a reviewer; he lives and breathes diesel performance. When Brandon puts a part on his daily driver, it's because he trusts it to withstand serious abuse.
The "Horrendous" Problem with Your Factory Diff Cover
Before the upgrade, Brandon pointed his camera at the stock rear axle and didn't mince words. He called the factory diff cover "horrendous" and highlighted problems every truck owner can relate to.
- A Nightmare to Service: "The factory ones don't have a drain plug," he explains. "In order to change the diff fluid on a stock Cummins, you got to take the whole cover off, reseal it. It's a headache."
- Old Fluid, Visible Rust: He suspected the gear oil in his truck was overdue for a change. "The diff lube was probably from 2007," he guessed, pointing out surface rust on the stock cover. Surface rust alone doesn't mean a cover is about to fail - if you're checking your own, look for pitting depth, seam leaks, deformation, and condition around the seal surface rather than judging by rust color alone.
- Limited Cooling Design: For a truck that tows, heat matters. The stock stamped-steel cover has less surface area and no fins compared to a finned aluminum cover, and aluminum conducts heat more effectively than steel - so a finned aluminum cover is designed to reject more heat. How much actual temperature difference that makes depends on airflow, fluid level, load, and ambient conditions; no differential-temperature testing was performed for this article. Understanding the real-world performance trade-offs is key for any owner.
What Changed After The Swap
After installing the SPELAB rear axle diff cover, the difference was immediate, both visually and functionally. This isn't just a shiny part; it's a piece of purpose-built engineering.
"You no longer have that ugly stock factory diff cover on the truck. Now, the advantage with this diff cover is it's all aluminum. It has like cooling fins in it that like help the heat get away from the axle."
4 Things Brandon Pointed Out In His Video
1. Maintenance: "Just Like Changing Your Oil"
This was the feature he kept coming back to - a fill plug and drain plug replacing a full cover removal for every fluid change.
"With this one, like I was saying, you have a fill plug, you have a drain plug... All you got to do is take that bottom drain plug out, drain your fluid, put your new fluid in. It's just like changing your oil."
2. Expected Cooling Benefit
Brandon, who hauls heavy loads, described the cooling design in his own words:
"When you're driving, the air is flowing and hitting your diff cover from underneath the truck... That actually cools it down. Your axle will stay cooler, the fluid won't boil, especially when I'm hauling the trailer with two of my monster trucks on it across the country."
To be precise: gear oil breaking down from sustained high heat shows up as reduced viscosity, faster oxidation, and additive breakdown long before anything resembling boiling - the practical concern is heat-related fluid degradation, not literal boiling. Brandon's comment reflects his in-cab impression, not a measured before-and-after temperature test.
3. Checking Fluid Level
No more guesswork or pulling a fill plug just to check your fluid - the integrated sight glass is designed to show fluid level without opening the cover.
"It is pretty awesome that there's a sight glass on it as you guys can see... to see your fluid level at any given moment."
4. Appearance
The visual difference between a rusty stock cover and a clean aluminum one is straightforward.
"It's going to look a lot better because we're going from whatever is going on with that," he said, pointing to the old rusty cover.
Verdict
For Brandon, the swap solved a real maintenance annoyance and gave him a cooling design he trusts for heavy towing. Whether it delivers the same result for your specific truck depends on your axle, fluid, and use case - the sections above and the FAQ below cover what to check before you buy.
Click Here to Shop SPELAB Aluminum Differential Covers for Your Truck!
Frequently Asked Questions (FAQ)
Q: How do I know which differential cover fits my exact truck model?
A: Year and model alone don't guarantee compatibility - the deciding factor is your actual axle. Confirm your axle manufacturer, exact size (for example AAM 11.5" or 11.8"), bolt pattern, and SRW/DRW configuration before ordering, using your axle tag, casting marks, or build sheet rather than assuming from the truck's model year.
Q: What comes in the box besides the cover itself?
A: Each kit is intended as a complete bolt-on solution including the cover, gasket, and mounting hardware - confirm the exact contents on the specific product listing for your application, since kits can vary.
Q: What kind of gear oil should I use, and how much does the cover hold?
A: Follow your truck's owner's manual for the correct gear oil weight (commonly 75W-90 or 75W-140 synthetic), and use the fill specification in the cover's included instructions rather than assuming a fixed capacity increase - it varies by axle and cover design. If your axle has a limited-slip differential, confirm whether a friction modifier additive is needed.
Q: Is this upgrade worth it if I only tow occasionally?
A: The maintenance convenience (drain plug, sight glass) benefits any owner regardless of towing frequency. The cooling design matters most under sustained heavy load - occasional light towing will see less of that benefit in practice.
Q: How difficult is the installation, and what should I check afterward?
A: It's a DIY-friendly job with basic hand tools like a socket set, torque wrench, and drain pan for most owners. Follow the included torque spec and bolt sequence rather than guessing, let any RTV or gasket sealant cure per the instructions before filling, and recheck for leaks and bolt tightness after your first real towing trip.
About the Author
John Lee
Mechanical Engineer | 10+ Years Experience
John has spent the last decade engineering and testing high-performance automotive components. Specializing in drivetrain durability and thermal management across Powerstroke, Cummins, and Duramax applications, he bridges the gap between OEM limitations and aftermarket performance. His philosophy: "Factory parts are just a starting point."
