Upgrading to a B&M torque converter is one of the most effective ways to transform your vehicle’s acceleration and driving feel. Whether you’re building a street machine, a tow rig, or a weekend warrior, a high-stall torque converter from B&M can dramatically improve launch performance and overall drivability. While the installation may seem intimidating, it’s a manageable job for any experienced DIY mechanic. This guide breaks the process into clear, detailed steps – from preparation and removal to installation and testing – so you can confidently install your B&M torque converter and unlock your car’s full potential.

Understanding Torque Converters and the B&M Advantage

Before diving into the installation, it helps to understand what a torque converter does and why B&M is a trusted name in performance driveline components.

How a Torque Converter Works

The torque converter is a fluid coupling that connects your engine to the transmission. It multiplies engine torque during launch, allows the engine to idle while the vehicle is stopped, and smooths out power delivery. A torque converter consists of three main elements: the impeller (pump), the turbine, and the stator. The stall speed is the engine RPM at which the converter locks up against the fluid, and a higher stall speed lets the engine rev higher before the vehicle moves, putting the engine in its power band for faster acceleration.

Why Choose B&M?

B&M has been a leader in automatic transmission components for decades. Their torque converters feature precision machining, furnace-brazed fins, and needle bearings for durability. B&M offers a range of stalls to match different engines and driving styles – from street-friendly “Holeshot” converters to full race units. Using a name-brand converter like B&M ensures consistent performance, reliable fitment, and access to technical support. For more information on B&M’s lineup, visit their official site: B&M Torque Converters.

Step 1: Gather Your Tools and Materials

Having the right tools on hand saves time and frustration. Below is a comprehensive list – including specialty items you may need for your specific vehicle.

  • B&M torque converter – verify part number matches your transmission model
  • Socket set (standard and deep well) – 3/8” and 1/2” drive
  • Wrench set – combination and flare nut wrenches for transmission lines
  • Torque wrench – ft-lb and in-lb ranges
  • Jack and jack stands – rated for your vehicle’s weight
  • Transmission fluid – type and quantity per vehicle specs (usually around 4–6 quarts for a pan drop, plus converter fill)
  • Safety goggles and gloves
  • Drain pan – at least 2-gallon capacity
  • Transmission pan gasket or RTV sealant
  • New transmission filter – highly recommended during converter swap
  • Flexplate bolts – often included with B&M converter, but verify
  • Alignment tool (optional) – for converter pilot alignment
  • Ratchet straps or transmission jack – if needed for access

Consult your vehicle’s service manual for specific bolt sizes and torque values. A B&M installation guide can also provide model-specific torque converter specs.

Step 2: Prepare Your Vehicle

Proper preparation is critical for safety and to prevent damage to the new converter. Follow these steps in order.

Safety Precautions

  • Park on a level, solid surface. Engage the parking brake.
  • Disconnect the negative battery terminal to prevent accidental cranking.
  • Raise the vehicle only with a hydraulic jack, then support it firmly on jack stands. Never work under a car held only by a jack.
  • Wear safety glasses – transmission fluid can spray.

Draining Transmission Fluid

Place a large drain pan under the transmission pan. Remove the pan bolts (start from the rear to avoid a flood), then carefully lower the pan. Allow the fluid to drain completely. Dispose of old fluid properly. If your transmission has a drain plug, use it first, then drop the pan.

Removing the Transmission Pan and Filter

With the pan removed, clean the pan thoroughly and set it aside. Remove the old filter by unbolting it or pulling it straight out, depending on design. Note the orientation – you’ll install the new filter the same way at reassembly. Now you have access to the torque converter bolts through the flexplate access hole (usually on the engine side).

Step 3: Remove the Old Torque Converter

With the transmission pan and filter out, you can access the torque converter bolts. Rotate the engine manually using a breaker bar on the crankshaft bolt to bring each flexplate bolt into view. Remove all the converter-to-flexplate bolts using a socket and wrench. They can be tight; use penetrating oil if needed.

Next, unbolt the transmission from the engine bellhousing. There are typically 4–6 bolts connecting the transmission to the block. Support the transmission with a jack or stand, then slide the transmission back slightly (about 1–2 inches) to free the converter from the flexplate. Be careful – the old converter is heavy and full of fluid. Let the converter drain into the pan, then slide it out of the transmission housing. Inspect the front pump seal and bushing; if they show wear, consider replacing them.

Step 4: Install the B&M Torque Converter

This is the most critical part. A misaligned converter can damage the pump or fail prematurely.

Aligning the Converter to the Flexplate

Before installation, pour about a quart of fresh transmission fluid into the new B&M converter. This prevents dry start and lubricates the internal components. Rotate the converter slowly while pushing it into the transmission. You should feel it “seat” in two distinct clicks as it engages the pump and stator splines. Measure from the bellhousing face to the converter mounting pad: the distance should match the depth of the old converter. If not, remove and re-seat. Install the converter-to-flexplate bolts – B&M often supplies the correct hardware. Hand-tighten first, then torque to the manufacturer’s specification (typically 30–40 ft-lb, but always verify your vehicle’s spec).

Torque Specifications

Use a quality torque wrench for these final turns. Over-tightening can strip the flexplate; under-tightening can cause bolts to shear. A good resource for common torque values is Summit Racing’s B&M converter page.

Step 5: Reassemble and Refill

Slide the transmission back into the engine, aligning the converter with the flexplate. Reinstall bellhousing bolts and torque them. Install the new transmission filter and pan gasket, then reattach the pan – use a gasket or RTV as recommended. Reconnect transmission cooler lines (if disconnected) and tighten to spec. Lower the vehicle, reconnect battery, and fill the transmission with the correct fluid through the dipstick tube. Start the engine and allow it to idle, shifting through each gear while stationary to purge air. Check fluid level and add as needed. Total fluid capacity may exceed 10 quarts if the converter was dry; the additional fluid will be sucked in as the converter fills.

Final Checks and Testing

  • With the engine idling, inspect for leaks around the pan gasket, converter dust cover, and cooler line fittings.
  • Monitor transmission fluid temperature during initial test drive – a sudden temperature rise could indicate low fluid or improper converter engagement.
  • Perform a road test in a safe area. Accelerate gently at first, then perform a few moderate launches to feel the higher stall speed. You should notice improved throttle response and stronger off-the-line pull.
  • After the test drive, re-check fluid level (engine idling, in Park) and verify no leaks.

Common Mistakes to Avoid

Even experienced mechanics can overlook details. Here are the top pitfalls when installing a torque converter:

  • Not pre-filling the converter – can cause pump cavitation and immediate failure.
  • Forcing the converter in – if it doesn’t slide fully home, you haven’t aligned the splines. Removing and re-seating is safer than forcing.
  • Using wrong flexplate bolts – too long can damage the converter; too short may not engage properly. Use B&M supplied bolts or verify length.
  • Skipping the filter replacement – old filter can become clogged, especially after converter swap.
  • Ignoring transmission cooler condition – if the converter failed, debris may have entered the cooler. Flush the cooler lines or install an auxiliary filter.
  • Driving with low fluid – can overheat the transmission quickly. Double-check levels after initial startup and test drive.

For additional troubleshooting, the B&M torque converter FAQ addresses common issues like vibrations, noise, and stall speed tuning.

Performance Gains: What to Expect

A properly installed B&M torque converter with a stall speed matched to your engine’s camshaft and gearing will produce noticeable improvements:

  • Faster 60-foot times – the engine stays in its power band at launch.
  • Smoother part-throttle shifts – the converter’s lockup characteristics improve transmission shift quality.
  • Enhanced towing capability – a higher stall keeps the engine in the torque curve when pulling heavy loads.
  • Better overall drivability – when matched correctly, a performance converter does not sacrifice street manners.

Remember that a torque converter alone isn’t a magic bullet. It works best with complementary upgrades such as a shift kit, transmission cooler, and proper engine tuning.

By following this guide, you can install a B&M torque converter with confidence. Take your time, use the correct tools, and double-check each step. The result will be a car that launches harder and drives better – exactly the payoff every enthusiast wants. If you encounter problems during installation, consult your vehicle-specific service manual or contact B&M technical support for expert assistance.