Dorman 999-666 Transmission Crossmember

Transmission Crossmember for Jeep Grand Cherokee

This Dorman transmission crossmember restores the support structure between the frame and transmission on compatible Jeep Grand Cherokee applications. Built as a standard replacement steel assembly, it helps address driveline movement caused by a rusted or weakened original crossmember.

Fits 1999-2004 Jeep Grand Cherokee, N/A. Part number 999-666 is a direct-fit, bolt-in replacement for specific applications and is made to retain the existing frame while renewing transmission support.

Key Features

• Steel construction for frame and transmission support
• Bolt-in design for specific vehicle fitment
• Standard replacement grade for OE-style service
• Frame width: 41.5 in.
• Length: 41.5 in.; width: 6.25 in.; height: 3.8 in.
• Mounting hole quantity: 8; mounting hole diameter: 12.2 mm
• Engine mounts included: No
• Transmission mounts included: No
• Mounting hardware included: No

Detailed Description

Dorman 999-666 is a transmission crossmember assembly for 1999-2004 Jeep Grand Cherokee models. It is engineered as a standard replacement steel frame component that supports the transmission and helps restore proper driveline alignment when the original crossmember has corrosion or structural wear. This part cross-references Monroe Shocks & Struts (e.g., 52058940, 52058940AB) for the same application.

Use this transmission crossmember when the factory support has deteriorated and the vehicle needs a direct replacement that retains the existing frame. The bolt-in configuration and specific fitment make it a practical service part for Jeep Grand Cherokee repair work. Part number 999-666 is listed for 1999, 2000, 2001, 2002, 2003, and 2004 Jeep Grand Cherokee applications.

What It Helps Fix

• Excess transmission movement caused by a rusted crossmember
• Driveline vibration related to weakened support structure
• Misalignment from a damaged or corroded original crossmember
• Loss of structural support at the transmission mounting area
• Vehicle downtime when the frame can be retained and the support replaced

Installation Notes and Tips

Verify the vehicle’s year, model, and existing crossmember dimensions before installation. This is a bolt-in, specific-fit assembly, so confirm mounting hole location and frame width match the application. Inspect surrounding frame areas for corrosion or damage before installing the new crossmember.

Quality Assurance

Dorman manufactures replacement frame and chassis components for service applications, and this transmission crossmember is built as a standard replacement steel assembly for the listed Jeep Grand Cherokee fitment.