Broken T Flite 727 Tailshaft

[Garys1969RR]

My 65 Belvedere has thrown another one at us. While racing it wed nite, it puked tranny fluid after the 1st run. On inspection today, found that the tailshaft had broken in 2, about 2 " behind the rear tranny mount! Was able to remove the entire tailshaft with the trans still in the car, thank goodness. My question is: what would cause it to break? The slip yoke was kind of loose in the rear bushing, so I am thinking that the loose fit caused a wobble where the driveshaft goes into the trans. Then the vibration caused it to eventually crack and break? Pretty strange, have never seen this before. The output shaft looks fine. It is straight and true. Any ideas?

- - - Updated - - -

Actually removed the extension housing that covers the tailshaft. I have another good used one to put on next week.

- - - Updated - - -

The cast aluminum extension housing is what broke in two. Not the output shaft.

 

[Cranky]

What do you use on the engine and trans for mounts? Solid on all 3 places or.......?

 

[WAYNES WORLD]

Bad tail bushing, front slip yoke or even a bad u joint can lead to a crack. How hard are you launching?
Wayne

 

[Garys1969RR]

What do you use on the engine and trans for mounts? Solid on all 3 places or.......?

It has Stock rubber mounts in all 3 positions. I have heard of the extension housing breakinf in FRONT of the rear mount, due to the huge inertia forces that are placed on the trans mount on a hard launch. But this one is broken BEHIND the rear mount.

 

[sleepar]

Anything bound up.. x2 on u joint... ring and pinion on deceleration may have caught a tooth...

 

[silversedan]

Have someone spin the driveshaft on a machine, I broke a ring and pinion on the starting line a couple of years ago , an after that I was breaking tail housings , had the shaft checked and it was screwed up , haven't broken one since.