Peterbilt 330/335/337 Drivetrain Parts

Frequently Asked Questions About Peterbilt 330/335/337 Drivetrain Parts

Will these drivetrain parts fit my specific Peterbilt 330, 335, or 337 model year?

Most drivetrain components for Peterbilt 330, 335, and 337 models are compatible across years 2005-2021, but there are important exceptions. Transmission mounting brackets changed in 2008, and driveshaft lengths vary between wheelbases. Always verify your truck's exact model year, engine type (Paccar PX-6, PX-7, or Cummins ISB), and transmission model (Allison 2000/3000 series or Eaton Fuller) before ordering. Check your OEM or door jamb sticker for specific configuration details.

What are the most common driveshaft and U-joint failures on these models, and which parts should I keep in stock?

The most frequent failures occur with carrier bearing assemblies (typically around 150,000-200,000 miles) and U-joints on the rear driveshaft section. We recommend keeping Spicer 1710 or 1810 series U-joints on hand, as these fit most 330/335/337 applications. Carrier bearings with greaseable centers last significantly longer than sealed units. For fleet operators, stocking a complete U-joint kit and spare carrier bearing can prevent costly downtime.

Can I upgrade from a single to tandem axle configuration, and what drivetrain modifications are required?

Converting from single to tandem axle requires extensive drivetrain modifications including a shorter main driveshaft, addition of an inter-axle driveshaft, different transmission output yoke, and potentially a different rear axle ratio. This conversion typically costs $8,000-$15,000 in parts alone. Most customers find it more cost-effective to trade for a tandem-equipped truck unless the chassis has exceptional value or specialized equipment.

What's the difference between OEM and aftermarket clutch kits, and which performs better for heavy-duty applications?

OEM clutches (typically Eaton or Sachs) are designed for exact factory specifications and generally last 250,000-350,000 miles under normal use. Aftermarket options like Perfection or Phoenix Friction often use ceramic facings that handle heat better for severe-duty applications but may engage more aggressively. For refuse trucks or heavy vocational use, ceramic aftermarket clutches often outlast OEM by 20-30%, while highway applications typically perform best with OEM organic material clutches.

How difficult is it to replace transmission mounts and engine mounts, and what special tools are needed?

Transmission mount replacement typically takes 2-3 hours and requires a transmission jack, basic hand tools, and sometimes a pneumatic chisel for stubborn bolts. Engine mounts are more involved, requiring 3-5 hours and engine support fixtures. The front engine mounts on 2008-2015 models are particularly challenging due to limited access. Many shops find it efficient to replace mounts in pairs, as labor overlap makes the second mount essentially free to install. Always support the engine and transmission properly to prevent damage to cooling lines and wiring harnesses.