Automatic Transmission Flywheel Covers & Flexplate Covers

What Does a Transmission Flex Plate Do?

A transmission flex plate bolts your crankshaft to the torque converter and carries the starter ring gear. It's the link that sends engine power into your automatic, so it has to match your engine, starter, and converter. It's also lighter than the flywheel a manual transmission uses.

If you're replacing or upgrading one, plan the front of the transmission as a package. Your flexplate, bolts, and converter all have to agree on bolt pattern and balance. Shop torque converters at the same time, and read our guide on how to choose a torque converter before you order.

For a stock-style replacement, Chevrolet Performance offers an OE-style flexplate for GM LSA engines. It also sells matching flywheel/flexplate bolts, so you can replace the hardware in one order. You'll find filters, rebuild parts, and other supporting pieces in our automatic transmission parts category.

Flex Plate vs Flywheel: Which One Does Your Automatic Need?

If you're running an automatic, you need a flexplate. A flywheel is a heavier part built to work with a manual clutch, and it won't bolt up to a torque converter. So when you're shopping for a flywheel for an automatic transmission, the flexplate is the part you want. Converting to a stick instead? Shop manual transmission flywheels.

Engine swaps are where flexplate choice gets tricky. LS swaps are a good example, because the flexplate has to suit both the engine and the transmission behind it. JW Performance "The Wheel" flexplates include a dished LSA/LSX version for Powerglide, TH350/400/700-R4, and 4L60E/70E/80E transmissions.

The same lineup covers 168-tooth Chevy 305-350 engines with a 1-piece rear main seal and 157-tooth Ford 289-302 engines. B&M flexplates are another option for street and strip automatics. Still picking a transmission? Start with our list of the best automatic transmissions for LS engine swaps, then match the flexplate to it.

How Do You Choose the Right Flexplate for Your Engine?

Choose a flexplate by matching balance, tooth count, engine fitment, and SFI rating to your build. Get one wrong and you'll hear it, feel it, or fail tech. Check these four details before you buy:

• Match the balance to your engine, since internally-balanced and externally-balanced engines need different flexplates.
• Match the tooth count to your starter, such as 153 or 168 teeth for Chevy and 157 or 164 for Ford.
• Match the engine make, size, and rear main seal style to the flexplate's listed fitment.
• Choose an SFI 29.1 flexplate if you race where a sanctioning body requires one.

For racing, you've got several SFI-approved options. PRW Pro-Series flexplates fit 1991-1997 Chevy 454/502 Gen V/VI big blocks. Allstar Performance offers an SFI flexplate for big block Chevy 454 engines.

ATI builds an SFI flexplate for Chevy LS1/2/6/7 and L68 engines. Scat race flexplates cover small block Chevy and big block Ford. Building a big block Ford? Meziere also makes a true billet flexplate for it.

Why Run a Flexplate Shield or SFI Flexplate?

You run a flexplate shield and an SFI flexplate to protect yourself if the parts between your engine and transmission fail. A flexplate shield, or safety shield, protects the driver if a flexplate or converter lets go. SFI 29.1 is the flexplate spec racing sanctioning bodies commonly require, so check your class rules before tech day.

Quick Time Bellhousing flexplate shields fit all small block Chevy engines and small block Ford 289/302/351C/351W engines. TCI offers flexplate safety shields for Chevy applications. TCI also sells an SFI flexplate for BBC 454 and a Premium Series flexplate for Ford 221-302.

Running a Powerglide? The black JEGS Powerglide transmission shield is built for it. For Pontiac builds, the JEGS Heavy-Duty SFI flexplate fits 1967-1979 Pontiac 326-455 V8 engines. It has 166 teeth and is internally balanced, so confirm your engine matches before you order. Pair the right shield with an SFI-rated flexplate and you're covered on both safety and tech.

What Do Flywheel Covers and Transmission Dust Covers Do?

A flywheel cover, also called a transmission dust cover or inspection cover, closes the opening at the bottom of the bellhousing. It keeps debris away from your flexplate, converter, and starter ring gear. It's a small part, but skipping it leaves those spinning parts exposed to whatever your tires kick up.

The TCI universal dust cover fits 1965-96 GM RWD transmissions, so it works on a wide range of classic GM builds. If you've lost the original cover or the old one is bent, it's an easy fix. Check your transmission's year range before you order, and replace a damaged cover when you have the car on jack stands.

Working on the housing too? Browse transmission bellhousings and components for the parts around your flexplate. Want more build help first? Our transmission and drivetrain tech articles cover converter selection, swaps, and setup. Shop All transmission and drivetrain parts to finish your automatic from the crank back.