Frequently Asked Questions

PML designs, manufactures, and sells sand cast aluminum differential covers, transmission pans, and valve covers for the automotive aftermarket. All PML products are available for purchase directly at yourcovers.com, over the phone, or through our network of authorized dealers and shops. PML also offers a selection of related accessories for our products. All PML products are made in USA.

All PML differential covers, transmission pans, and valve covers are made in the USA. PML designs and manufactures every product in Southern California.

Installation instructions for all PML differential covers, transmission pans, and valve covers are available by request. Contact PML directly and we will email them to you. See Contact Us for phone and email details.

Torque specifications for PML differential cover, transmission pan, and valve cover bolts are included in the installation instructions. If you do not have the installation instructions for your PML product, contact us and we will send them to you. See Contact Us.

PML transmission pans and differential covers use one of two magnetic drain plugs depending on the product, 1/2-20 UNF threaded magnetic drain plug or 3/8-14 NPT threaded magnetic drain plug.

1/2-20 UNF Threaded Magnetic Drain Plug

Most PML pans and covers use a 1/2-20 UNF magnetic drain plug. When installed, you can see the 9/16 inch hex head of the drain plug.

Washer Included With 1/2-20 Magnetic Drain Plug

This washer is reusable. Between uses, rub both sides on 100-grit sandpaper and wipe clean. Prefer a crush washer? Use Dorman oil drain plug gasket, part number 097-027.

3/8 NPT Magnetic Drain Plug

The 3/8 NPT magnetic drain plug uses a 5/16 socket head. It looks like this when installed:

PML pans are designed to work with OEM stock filters — no aftermarket filter or extension required.

How It Works

If the filter does not bolt directly onto the valve body, the PML pan includes integrated fingers or posts built into the floor of the pan. These rise to the height of the stock pan and hold the filter securely in place.

• Uses the same readily available OEM stock filter while provides the cooling benefit of increased oil capacity and finned cast aluminum construction
• Fluid level and pick-up point remain identical to the stock pan
• Original transmission fluid dynamics are fully preserved
• No stagnant oil layer — active mixing of fluid from the filter intake to the transmission, oil return to the pan, and vehicle movement keep fluid circulating

PML Design vs. Filter Extensions

The correct gasket for your PML transmission pan, differential cover, or valve cover depends on the specific product. The SPECIFICATIONS section on each product page includes the gasket details required for that part. If you need help determining the right gasket, contact PML and we can assist.

PML uses sand cast aluminum for all differential covers, transmission pans, and valve covers. The combination of material and manufacturing process is what makes PML parts genuinely heavy duty — stronger, better looking, and more thermally efficient than die-cast or stamped alternatives.

Why Aluminum

• High strength-to-weight ratio — strong without being heavy
• Excellent heat transfer — helps cool transmission and differential oil

What Is Sand Casting?

Sand casting is the process of pouring molten aluminum into a sand mold, producing one thick, solid, heavy-duty part. The resulting rough surface texture — like the feel of sand — creates more surface area than a smooth finish, allowing for better and faster thermal dissipation. Many enthusiasts also feel that sand castings more closely replicate the original, classic look of factory parts than die-cast or stamped alternatives.

How Manufacturing Methods Compare

PML does not guarantee a drop in fluid temperature, but many customers who install a PML transmission pan or differential cover report an average reduction of 5 to 10 degrees. Results vary based on a number of factors.

What Affects Fluid Temperature

• Vehicle configuration and drivetrain setup
• Driving conditions — city, highway, towing, or hauling
• Ambient weather and temperature
• Load and stress on the transmission
• Where fluid temperature is measured

Some customers only notice temperature drops under heavy use such as towing or climbing hills. Others report that fluid temperature returns to a normal range more quickly after high-stress driving. If your transmission fluid temperature was already at the optimal operating range before installing a PML pan, the system may maintain that same temperature — which is exactly what it is designed to do.

PML does not have a retail storefront, but in-person order pickups are available by appointment at our Southern California facility.

How to Schedule a Pickup

• Call PML to place your order over the phone
• We will verify the part is in stock and schedule a pickup time
• Pickup appointments are available Monday – Friday, 9am to 3:30pm
• Our facility doors are kept locked — scheduling ensures someone is ready to assist when you arrive

Yes, PML sells and ships differential covers, transmission pans, and valve covers internationally. Please review our International Customers guidelines for shipping details, costs, and any applicable restrictions before placing your order.

PML does not offer free shipping. Shipping costs are calculated based on the delivery address and the size of the order. For full details on rates, carriers, and return policies, see the Shipping and Return Policy.