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CMcAllister · 05-25-2020, 12:24 AM

People have been preaching to these guys for years. And plenty of them reply "been doing it my way for years and nothing ever happened".

No need for this to happen. With no low band apply in low gear, and the roller clutch completely fails under load in low gear, the engine freewheels. At somewhere north of 5000RPM x low gear ratio - 12000+RPM - the cast OE front drum explodes.

The use of an aftermarket steel or aluminum drum and/or a low band apply valve body, prevents this from happening if the roller clutch fails.

Just because the car moves in low gear doesn't mean the roller clutch hasn't failed. I've seen them in transmissions that came out of a car - that was being driven but had the rear end recently broken and repaired - with half the springs mashed and only half of the elements holding. This can happen with a 904, but the 727 is the one with the heavy OE drum that blows up.

Failing to follow instructions for how to drive the car and/or a driveline or rear end failure under load in low gear will kill the roller clutch. Sometimes it still works well enough to get it into the water or to the starting line, with ugly results.

05-25-2020, 12:24 AM	#2
CMcAllister Senior Member Join Date: Sep 2006 Location: Fulton County, PA Posts: 617 Likes: 17 Liked 920 Times in 259 Posts	Re: "Live From" Numidia Dragway People have been preaching to these guys for years. And plenty of them reply "been doing it my way for years and nothing ever happened". No need for this to happen. With no low band apply in low gear, and the roller clutch completely fails under load in low gear, the engine freewheels. At somewhere north of 5000RPM x low gear ratio - 12000+RPM - the cast OE front drum explodes. The use of an aftermarket steel or aluminum drum and/or a low band apply valve body, prevents this from happening if the roller clutch fails. Just because the car moves in low gear doesn't mean the roller clutch hasn't failed. I've seen them in transmissions that came out of a car - that was being driven but had the rear end recently broken and repaired - with half the springs mashed and only half of the elements holding. This can happen with a 904, but the 727 is the one with the heavy OE drum that blows up. Failing to follow instructions for how to drive the car and/or a driveline or rear end failure under load in low gear will kill the roller clutch. Sometimes it still works well enough to get it into the water or to the starting line, with ugly results.