Change TH350 & TH400 Shift Points with an Adjustable Vacuum Modulator

How To Adjust TH350 and TH400 Shift Points with a Vacuum Modulator
How To Adjust TH350 and TH400 Shift Points with a Vacuum Modulator
 

Installing the B&M Vacuum Modulator for GM TH350 & TH400 Automatic Transmissions, Part# 20234

The B&M Adjustable Vacuum Modulator (Part# 20234) comes pre-adjusted for ‘normal’ shift points, but it is fully adjustable (see below), allowing you to customize the shift points (within a range of 2-4 mph). This unit is designed for use with select applications, including GM TH400 and TH350 transmissions.

  • Allows you to tailor shift points
  • B&M Quality
  • Comes pre-adjusted
  • Fully adjustable

Please note: If you have a big camshaft and your engine does not make adequate vacuum, you will not be able to make the stock or B&M modulator work properly, usually resulting in late, hard shifts. A minimum of 12″ Hg engine vacuum is required for proper operation.

Installing the Vacuum Modulator

Adjusting Shift Points

You can adjust the modulator with a small screwdriver. Turn the adjustment screw clockwise to raise shift points and counter-clockwise to lower shift points.

Get the Kit

B&M Vacuum Modulator for GM TH350/TH400 Automatic Transmissions ~ Part # 20234 on Amazon

Questions?

Need a product recommendation for your vehicle or application? Give B&M a call at (866) 464-6553