Frequently Asked Questions About Peterbilt 387 Drivetrain Parts

What years and models are compatible with Peterbilt 387 drivetrain components?

Peterbilt 387 drivetrain parts are specifically designed for model years 1999-2010. Most transmission components, driveshafts, and differentials are interchangeable within these years, but always verify your specific VIN and component numbers. Parts from the 379 and 385 models may also fit, but mounting points and lengths can vary. We recommend checking your existing part numbers or contacting our team with your VIN for exact compatibility.

What are the most common drivetrain failures on the Peterbilt 387, and which parts should I keep on hand?

Based on customer feedback, the most frequent issues include U-joint wear (especially on the forward driveshaft), carrier bearing failures around 300,000-400,000 miles, and transmission output seal leaks. We recommend keeping spare U-joints, carrier bearings with mounting hardware, and output seals in stock. Many drivers also report clutch brake wear on manual transmissions, so having a replacement clutch brake can prevent roadside downtime.

Can I upgrade my Peterbilt 387 from a 10-speed to 13-speed transmission, and what parts are needed?

Yes, upgrading from a 10-speed to 13-speed transmission is possible but requires several components beyond the transmission itself. You'll need a compatible bellhousing, potentially a different driveshaft length, updated shift linkage, and ECM programming. The existing clutch may work if it's a 2-inch input shaft, but verify specifications. Labor typically runs 8-12 hours for a complete swap. Consider your rear axle ratios as well, as they may need adjustment for optimal performance.

How do I identify the correct driveshaft length and specifications for my Peterbilt 387?

Driveshaft specifications vary based on wheelbase, suspension type, and transmission configuration. The most accurate method is measuring from the transmission output yoke to the differential input yoke at ride height. Standard lengths range from 50-75 inches for the rear shaft. Look for stamped numbers on your existing driveshaft tube for series type (1710, 1810, etc.). Critical measurements include collapsed length, tube diameter, and U-joint series. When in doubt, provide your VIN and we can reference OEM specifications.

What preventive maintenance can extend the life of my Peterbilt 387 drivetrain components?

Regular greasing of U-joints every 5,000-7,000 miles prevents premature wear. Check driveshaft balance weights haven't shifted and inspect for dents or damage monthly. Change differential fluid every 100,000 miles or annually, and transmission fluid based on severity of use (typically 250,000-300,000 miles for highway use). Monitor carrier bearing play during pre-trip inspections - any clicking or excessive movement indicates replacement is needed. Keep driveline angles within 3 degrees to prevent vibration damage.