ATP Parts JX-66 Automatic Transmission Modulator Valve

ATP Parts JX-66 Automatic Transmission Modulator Valve

ATP Parts JX-66 is an exact-fit automatic transmission modulator valve for select GM trucks and vans from 1988-1990. It is built for applications using a 1 red stripe identification mark and a 2.959-inch hose length, with coverage for 3.73:1 or 4.10:1 ratio configurations.

Key Features

• Automatic transmission modulator valve for select rear-wheel and four-wheel drive GM applications
• Length: 2.959 inches
• Hose quantity: 1
• Identification detail: 1 red stripe
• Exact-fit replacement from ATP Transmission Components
• Cross-reference: Dorman - HELP 14658

Application Details

This ATP Parts JX-66 modulator valve is used in 1988-1990 Cadillac Brougham and Chevrolet and GMC truck, van, and Suburban applications that call for the red-stripe modulator specification. It is listed for vehicles such as Chevrolet Blazer, C1500, C2500, C3500, G10, G20, G30, K1500, K2500, K3500, P30, and related GMC and Cadillac applications with the matching transmission and axle ratio notes shown in the fitment data. For buyers searching by vehicle, ATP Parts JX-66 is a direct replacement for select Chevrolet C1500 and GMC K1500 applications with the specified modulator setup.

What This Part Helps Address

• Incorrect transmission shift timing caused by a worn modulator valve
• Harsh or delayed automatic transmission operation
• Vacuum-modulated transmission control issues
• Replacement needs on vehicles with the 1 red stripe specification
• Service repairs on 3.73:1 or 4.10:1 ratio applications

Installation Notes and Tips

Verify the transmission code, axle ratio, and red-stripe identification before ordering. This part is listed for applications without EGR in several fitments, and some vehicles are noted as THM400, 3L80, THM425, or THM475/M40 specific. Confirm hose length and routing against the original part to ensure proper vacuum connection and transmission response. For best results, compare the old modulator valve markings and vehicle fitment notes before installation.

Quality Assurance

ATP Transmission Components are positioned as exact-fit replacement parts, built to match the original application requirements for the listed vehicles. ATP Parts JX-66 is intended to provide the correct fit and function for the specified GM automatic transmission applications.