What is the purpose of the drive or flex plate - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Brianmax · 04-26-2011, 12:23

I am rebuilding my first engine. A 1989 Ford/Indmar 351W. The drive plate bolts onto the flywheel. The drive plate has the gear in the middle that matches up to the transmission. Then it has 5 springs surrounding that gear. I am just curious the purpose of a drive plate in an engine (i.e. why not just bolt the tranny directly to the flywheel) and what those little springs are for.
Thanks.

**R.S.LOGAN** · 04-26-2011, 12:32

Cushions / absorbs / prevents judder when drive taken up .

**jwko** · 04-26-2011, 14:57

I think your talking about the clutch disk. The clutch disk rides on the flywheel and is engaged/disengaged by the throwout bearing and pressure plate when pressing in or releasing the clutch pedal.

If you bolted the transmission directly to the engine then there would be nothing to disengage the transmission when you stopped or to keep it from taking off when you started the engine. In a automatic transmission the torque converter regulates torque from the engine to the transmission. In a manual transmission, the clutch regulates it.

**R.S.LOGAN** · 04-26-2011, 15:05

On the clutch centre / driven plate they are also known as anti-rattle springs .If they are knacked you get clutch judder .

**Big Block Ford** · 04-29-2011, 03:10

Yes I think you are talking about the clutch disk on a manual transmission. If the transmission is hooked up directly then the next time you go to park in the garage you will keep going right through the back wall and over the neighbours hedge. There will be no stopping you.