Timken LM78310A Differential Pinion Race - Front Outer, Rear or Rear Inner

Timken LM78310A Differential Pinion Race

The Timken LM78310A differential pinion race is a tapered roller bearing cup built for driveline and axle service where precise load control matters. It is used in front outer and rear inner applications on select Audi and Maserati models, including 1991 Audi 100, 1991 Audi 80, 1991 Audi 90, and several Maserati rear axle applications.

Key Features

• Tapered roller bearing race for differential pinion service
• Outside diameter: 2.440 in. (61.97 mm)
• Width: 0.535 in. (13.60 mm)
• Bearing cup radius: 0.059 in. (1.50 mm)
• Supports both radial and axial loads in compact driveline assemblies
• Timken LM78310A interchange reference

Detailed Description

Timken tapered roller bearing components are engineered for driveline applications that require stable load handling, durability, and consistent fit. The LM78310A differential pinion race is the outer cup used with the matching cone, and Timken recommends replacing the inner cone and outer cup together to maintain bearing life and reliability. This part cross-references Timken LM78310A for the same application. Compatible vehicle coverage includes 1991 Audi 100 front outer, 1991 Audi 80 front outer, 1991 Audi 90 front outer, 1984-1987 Maserati Biturbo rear inner, 1987 Maserati Spyder rear inner, 1989-1990 Maserati 228i rear inner, 1989-1990 Maserati 430i rear inner, and 1989-1991 Maserati Spyder rear inner.

What It Helps Address

• Noise from a worn differential pinion bearing race
• Excessive play in the pinion bearing assembly
• Rough bearing surfaces that affect driveline smoothness
• Improper bearing preload caused by worn cup surfaces
• Restoration work on Audi and Maserati axle assemblies

Installation Notes and Tips

Verify the bearing dimensions before installation: 2.440 in. outside diameter, 0.535 in. width, and 0.059 in. cup radius. Replace the matching cone at the same time, and inspect the pinion shaft, housing bore, and related bearing surfaces for wear or scoring. Press the race into place using proper bearing service tools to avoid damage to the cup or housing.

Quality Assurance

Timken is a recognized global leader in tapered roller bearings, with engineering focused on higher-speed operation, heavier load capacity, and longer service life. The LM78310A is built to Timken bearing standards for driveline and axle service.