Frequently Asked Questions About Peterbilt 387 Transmission Coolers

What years of Peterbilt 387 trucks are these transmission coolers compatible with?

Our transmission coolers are designed to fit Peterbilt 387 models from 2000 to 2010. However, compatibility can vary based on your specific engine configuration and transmission type. We recommend checking your truck's VIN and transmission model number before ordering. If you have a Caterpillar C15, Cummins ISX, or Detroit Series 60 engine, most universal-fit coolers will work, but mounting brackets may differ between model years 2000-2004 and 2005-2010.

How difficult is it to install a transmission cooler on my Peterbilt 387, and what tools will I need?

Installation typically takes 2-4 hours for someone with basic mechanical skills. You'll need standard hand tools including wrenches (typically 13mm, 15mm, and 17mm), a drill with metal bits for mounting brackets, transmission line disconnect tools, and a drain pan. The most challenging part is usually routing the transmission lines and ensuring proper clearance from moving parts. Many drivers report that having a second person helps significantly when mounting larger coolers. Professional installation typically costs $200-400 if you prefer not to do it yourself.

What size transmission cooler do I need for my Peterbilt 387, and how do I know if I need an upgrade?

For standard highway driving, a 20,000-24,000 GVW rated cooler is sufficient. If you're hauling heavy loads regularly, operating in mountainous terrain, or experiencing transmission temperatures above 200?F, upgrade to a 30,000-40,000 GVW rated cooler. Signs you need a larger cooler include transmission slipping, burnt fluid smell, or fluid temperatures consistently exceeding 180?F. Most Peterbilt 387s benefit from adding an auxiliary cooler in series with the factory unit rather than replacing it entirely.

Are aluminum or steel transmission coolers better for my Peterbilt 387?

Aluminum coolers offer better heat dissipation and are 40-50% lighter than steel units, making them ideal for weight-conscious operations. They resist corrosion better in road salt conditions but can be damaged more easily by road debris. Steel coolers are more durable against impacts and typically cost 20-30% less, but they're heavier and may rust over time. For most Peterbilt 387 applications, aluminum plate-and-fin style coolers provide the best balance of cooling efficiency and durability.

Do I need to modify my transmission lines or add a filter when installing an aftermarket cooler?

Most quality transmission cooler kits include the necessary fittings and hose to connect to your existing lines, but you may need to purchase additional transmission hose if relocating the cooler far from the stock position. Adding an inline transmission filter is highly recommended when installing a new cooler, as it prevents debris from the installation from circulating through your transmission. Use transmission-specific hose rated for at least 300 PSI and 300?F. Avoid using standard hydraulic hose, as it can deteriorate from transmission fluid additives.