Skip To Content

Specifications

The PAI 900158 Auxiliary Mainshaft (OEM Fuller 4300904) is a replacement component designed for use in Fuller auxiliary transmission sections found in various Freightliner, Mack, and other heavy-duty trucks. Key features include a 5/8-18 thread and dual-outer tooth counts (18 & 10) that match the original gear geometry for proper meshing and wear pattern. Constructed from hardened steel, it resists fatigue, wear, and torsional stress. Crafted by PAI Industries, which follows rigorous quality / ISO standards, this mainshaft helps ensure smooth shifting, reduced vibration, and reliable service life. Wofford Truck Parts stocks this part for fleet operators, shops, and operators demanding dependable performance under harsh operating conditions.
Weight
18.64

Compatibility

Freightliner – various models (FLD, Classic, Cascadia, Century, Columbia) — 1980s–2010s

Mack – CH, CL, CX, and other Mack models that were specified with Fuller transmissions — 1980s–2010s.

Volvo – VN / VNL series and other Volvo tractors equipped with Fuller transmissions — 1990s–2010s.

Kenworth – T600, T800 and other models when fitted with Fuller transmissions — 1980s–2010s.

Peterbilt – 377, 379, 386, 387 and other heavy-duty models with Fuller transmissions — 1980s–2010s.

International/Navistar – 9200/9400/9900 and other line-haul models that used Fuller transmissions — 1990s–2000s.

Various vocational & specialty OEMs (eg. refuse, mixer, heavy-haul chassis) that spec’d Eaton/Fuller transmissions — 1980s–2010s.


Alternative Part Numbers

  • Freightliner FUL4300904
  • Fuller 4300904
  • Mack 3088-4300904
  • Other: F6HZ7061CA
  • PAI 900158
  • S-E322

Related Parts

Auxiliary Mainshaft
PAI Industries, Inc. Part No: 900158
$259.52 View Part

This website uses cookies to provide users the best possible experience. Learn more. Please also review our terms of use and terms of sale.