Adjustable Vacuum Modulator B&M Transmission

Description

Product Overview

The B&M 20234 Adjustable Vacuum Modulator is engineered for durability and precision. Constructed from high‑grade injection‑molded plastic, the unit resists corrosion and heat while maintaining the flexibility needed for fine adjustments. It features a 0.25‑inch vacuum line inlet and a matching 0.25‑inch flare outlet, allowing seamless integration with GM TH350 and TH400 transmission systems. Pre‑adjusted from the factory for standard shift points, the modulator can be tuned within a 2‑4 mph range to suit individual driving preferences, delivering smoother gear changes and improved fuel efficiency.

Usage

Designed for both professional mechanics and DIY enthusiasts, this vacuum modulator fits directly into the transmission’s vacuum circuit. Ideal for daily commuters, performance enthusiasts, and fleet vehicles, it helps maintain optimal shift quality under a variety of load conditions. Installation requires basic hand tools and takes only minutes, making it a practical upgrade during routine service or transmission rebuilds.

Why Choose Us

B&M is a trusted name in automotive components, and this modulator reflects the brand’s commitment to quality. Each unit undergoes rigorous testing to meet OEM specifications, ensuring reliable operation from day one. The product carries a one‑year limited warranty, providing peace of mind and support from the manufacturer. With over 96 positive customer reviews and a strong best‑seller ranking in the transmission modulator category, you can be confident in the performance and longevity of this part.

Key Features

• Fully adjustable vacuum modulator for custom shift point tuning (2‑4 mph range)
• Durable plastic construction resists corrosion and heat buildup
• Pre‑set for standard GM TH350/TH400 shift points for quick start
• 0.25‑inch vacuum inlet and flare outlet for easy integration
• Backed by a 1‑year limited warranty and genuine B&M quality assurance

FAQ

How do I adjust the shift points on the B&M vacuum modulator?

Turn the adjustment screw clockwise to raise the shift point and counter‑clockwise to lower it. Each full turn changes the shift point by approximately 0.5 mph, allowing precise calibration within the 2‑4 mph range.

Is this modulator compatible with both TH350 and TH400 transmissions?

Yes, the B&M 20234 model is designed to work with the vacuum circuits of both GM TH350 and TH400 automatic transmissions.

What tools are required for installation?

Basic hand tools such as a screwdriver, pliers, and a torque wrench are sufficient. No special equipment is needed.

Can I use this modulator on a vehicle with a different transmission?

The unit is specifically engineered for GM TH350 and TH400 applications. Using it on other transmission types may result in improper operation and is not recommended.

What does the one‑year limited warranty cover?

The warranty covers defects in materials and workmanship under normal use. It does not cover damage caused by improper installation, misuse, or external factors.