Frequently Asked Questions About International WorkStar Drivetrain Parts
Which drivetrain components are most compatible with my WorkStar model year?
International WorkStar trucks manufactured from 2008 to 2017 share many common drivetrain components, but there are important distinctions. Models from 2008-2010 typically use Dana Spicer 1710 or 1810 series driveshafts, while 2011-2017 models often feature Meritor RPL20 or RPL25 series. Always verify your specific model's OEM and axle configuration before ordering, as WorkStar 7300, 7400, and 7600 series may have different torque ratings and mounting specifications despite sharing the same model year.
What are the signs that my U-joints or carrier bearing need replacement?
Common indicators include vibration that increases with speed (typically starting around 35-45 mph), clunking sounds during acceleration or deceleration, and visible rust streaks near the U-joint caps. For carrier bearings, look for excessive play when manually checking the driveshaft, rubber deterioration around the bearing mount, or a humming noise that changes pitch with vehicle speed. WorkStar drivetrains typically show these symptoms between 150,000-250,000 miles depending on load conditions and maintenance frequency.
Can I upgrade from a two-piece to a one-piece driveshaft on my WorkStar?
While technically possible on some WorkStar configurations, this conversion requires careful measurement of your wheelbase and critical speed calculations. WorkStars with wheelbases under 180 inches are generally good candidates, but you'll need to verify proper pinion angle (typically 1-3 degrees) and ensure your transmission output shaft and rear differential input yoke are compatible. Most conversions require a slip yoke eliminator kit and may need custom balancing. Consider that one-piece shafts eliminate the carrier bearing maintenance but may transmit more vibration to the cab.
What's the proper torque specification for WorkStar driveline components?
U-joint strap bolts typically require 26-30 ft-lbs for 7/16" bolts and 41-47 ft-lbs for 1/2" bolts. Companion flange nuts vary by series: Meritor RPL series call for 250-280 ft-lbs, while Dana Spicer 1710/1810 series require 225-250 ft-lbs. Carrier bearing mount bolts should be torqued to 45-50 ft-lbs. Always use new self-locking nuts on critical connections and apply medium-strength threadlocker to companion flange bolts. These specifications assume clean, dry threads - reduce by 15% if using anti-seize compounds.
How difficult is it to replace a clutch in a WorkStar without removing the transmission?
Most WorkStar models with Eaton Fuller transmissions allow clutch replacement without full transmission removal, though it requires supporting the transmission properly and having 24-30 inches of clearance behind the cab. You'll need a transmission jack, clutch alignment tool specific to your spline count (typically 1.75" x 10 or 2" x 10), and approximately 6-8 hours for a experienced technician. The process involves removing the driveshaft, disconnecting the clutch linkage, and sliding the transmission back just enough to access the clutch assembly. Models with Allison automatics obviously don't require this service, but torque converter access follows similar principles.
