Custom Bay: Spiffin' Up a Diff

Give Your Customer's Differential a Different Look and More Oil Capacity.

Jan. 1, 2020

3 min read

Custom Bay aluminum differential cover differential covers diffs Oasis Wheels specialty parts vehicle customization

In a down economy, selling aftermarket upgrades can be a tough proposition. The products that will move off the shelves usually are simple, affordable and functional. And it doesn't hurt if they look good, too. A custom differential cover has all of those features, along with a bit of bling.

How so? Gears like oil — lots of it. Run them dry, and they'll grind to a halt in short order. Keep them bathed in plenty of lube, and they not only wear less, but also stay cooler. That's important when a pickup is hauling heavy loads. Too much heat, and the oil will lose its lubricity, the very thing you need from it the most.

Going to a larger differential cover is a quick and simple way to give your customers' gears more of what they like. Not only that, many diff covers now on the market have some sort of custom logo or design on them to dress up the rear end. That's especially popular on lifted trucks, because it's the first thing you often see on an elevated suspension. And some companies — such as Oasis, which makes the Ram's head unit shown here — can also put your shop or company logo on the cover. (Which is even better than free advertising, because the customer pays for the product!)

Getting down to the technical details, a diff cover typically increases gear oil capacity by about a quart. In addition, it's usually constructed of a heat-treated aluminum alloy, enabling it to dissipate heat more quickly than the stock stamped-steel unit. Cooling fins also can help to reduce the oil temperature for extended gear and bearing life.

The design of the Oasis cover in particular simplifies oil changes, with two plugs to facilitate both draining and filling. The drain plug is magnetic as well, in order to attract any metal particles that otherwise would grind between the gear teeth.

Installing a diff cover is a pretty straightforward deal, with no special tools needed. Just be sure to handle the drain fluid with care, so you don't make a mess or get fined for environmental contamination. And be sure to fill the pan as full as possible, making sure the excess is dripping out the filler hole. Your gears — and customers — will thank you for it.

Steve Temple is a freelance technical writer and photographer with more than 25 years' experience. He has served as director of sales and marketing for Shelby American and as online editor for major magazines such as Hot Rod, Car Craft and Rod & Custom.