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I am working with one of the sales engineer for diesel engine and he asked if company provides Clark SAE3 flexplate. The spec I see includes 'Flywheel for Dana Spicer 13-15-17, with SAE3 housing'.
I am wondering what is the difference between both of them? I am confuse between terminology flex pate and flywheel.
Can someone, please, elaborate difference between flexplate and flywheel.
Also, it will be wonderful if someone can provide literature link about it.


RE: Flexplate/flywheel

Hello Dave,
Thank you very much for providing WIKI link but that is not enough to understand. The underground mining vehicle has 5 speed automatic transmission, and engine has dana spicer 13-15-17 flywheel. I want to understand how they fit clark SAE3 flex plate with it.
Some online articles use it as flywheel/flexplate. its not same, than why they use it interchangeably?

RE: Flexplate/flywheel

I know that flex plates are mounted to torque converter and assembly is attached to engine flywheel. I have attached one amazon link, it say that its flexplate. I wonder how it works. It also has ring gear.


RE: Flexplate/flywheel

In a conventional automotive setup on the engine facing side of the torque converter there is a ring of raised threaded bosses. These are used to bolt to the flexplate, which in itself is bolted to the end of the crankshaft. The flexplate also carries the ring gear for the starter. Your Amazon link is very slightly unusual in that it has mounting holes for two different torque converters. Manual trans needs a flywheel because it doesn't have the rotational inertia of the torque converter. I expect non technical people might confuse the terms flywheel and flexplate.


Greg Locock

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RE: Flexplate/flywheel

Hello Greg,
Can I say that it will be either flywheel or flex plate which will attach to crankshaft center? I have attached two images, I have worked in forklift industry and came across plates as shown in image 2. Image 1 has FLEXPLATE with RING gear. I understand that image 2 plates are bolted to flywheel. I call these plates as FLEX PLATES.
Please, correct me if I am wrong.
I would like to understand where we don't use flywheel and instead use flex plate shown in image 1. Why customer asking for Clark sae3 flex plate when engine has dana spicer 13-15-17 confi flywheel.


RE: Flexplate/flywheel

A flywheel is a rigid weighted mass attached to the crankshaft. The flexplate is a flexible coupling used to couple the engine to a load. The flywheel usually has the ring gear for the stater. If there is no flywheel the flexplate may have a ring gear.

Sometimes, especially in the case of automotive engines, you will have a flexplate and no flywheel. In other cases such as a generator, you will have a flexplate and a flywheel. With the exception of manual transmissions or long coupled assemblies, most systems will have a flexplate of some sort.

In your picture that is a flexplate.

RE: Flexplate/flywheel

Thank you, @TugboatEng.
That helps lot.
So in both pictures they are flex plates. But image 1 flex plate directly bolted on the crankshaft while image 2 flex plate is bolted to fly wheel of the engine. Right?

RE: Flexplate/flywheel

That is exactly correct.

RE: Flexplate/flywheel

Thanks, TugboatEng.

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