727 yoke failure at speed, the carnage

[dvw]

As promised the forensics after my buddys yoke broke on his 9 second 64 Dodge. This trans was on its maiden voyage. It didnt make it. Took out the drive shaft , floor tunnel , and broke the trans it had just gone into 3rd. This is a 65 push button so the parts appear a little different than a newer 727. It needs a governor support, rear pump cover, output bearing (yes it shattered the bearing), output shaft (yes its bent), and tail housing. Though the trans has some other issues they were not related to this failure.
Doug

 

[BSB67]

Holy crap. I assume he was at 100+ mph?

 

[VANDAN]

We just finished the '65 PB 727 for my '63 MW build, in late Spring. The builder changed out some of the internals, for a more heavy duty power band. Seeing that, makes me hope that He went HD enough !

 

[dvw]

This was not a fault of the trans. It was a driveshaft yoke failure. We currently run 2 push button 727s . One 850+hp with a trans brake, one 900+hp , foot brake. They live just fine. Most internals a basically stock.
Doug

 

[493 Mike]

This was not a fault of the trans. It was a driveshaft yoke failure. We currently run 2 push button 727s . One 850+hp with a trans brake, one 900+hp , foot brake. They live just fine. Most internals a basically stock.
Doug

Are you using the billet front clutch retainers?
Mike

 

[dvw]

Only with aluminum drums. The additional failure on this trans looks to be an aftermarket KD servo. The piston seal leaked and cross fed the KD band and front clutch circuits. Did this affect the yoke by applying 2 gears at once? It's possible. Looks at the high clutch and drum. This trans was on its 1st pass. This was a brand new drum according to the owner.
Doug

 

[oldbee]

Nasty!

 

[threewood]

Yikes! Was that a stock trans yoke?
The drum and steels look like they got hot.

 

[493 Mike]

Well, that sucks$$$$$$!
Mike

 

[F4R/T]

I’d be so thankful that’s all that happens car stayed dirty side down and everyone is ok! Hopefully it wasn’t a numbers matching trans , so lucky

 

[watermelon]

rough

not that it would have helped but do the cars run a rear driveshaft loop as well as a front?


watermelon

 

[1 Wild R/T]

Looks familiar... Saw a similar failure on a 440-6 Challenger back in the 90's... Like you said, not the trans fault...