What happened to my AOD?

[ericl]

I've wanted to swap out my AOD for a while. I've never liked autos and this one was no exception. When it "broke" this summer it was the perfect time to swap in a t5. I want to have it fixed so I can sell it and want to know what went on inside. I took off hard from a complete stop. It drove thru first and second without a problem. It shifted into third and nothing, no bang, no noise, no power. It was like I shifted into neutral. A few weeks back I removed the AOD. Today I saw the input shaft was broke. I fished a 1.5" splined piece out of the torque converter. I was also able to pull the center input shaft all the way out of the tranny. I saw no mechanical fasteners or retainers that would keep that shaft in. Is it supposed to be able to come out the front? What else might be wrong?

Here are some details on the car:
65 fastback
approx 300hp/290lbft 302 small block
4:11 rear
Lentech valve body
90 or 91 AOD (I recall that my tranny was the era for the improved input shaft)
installation went fine (no binding, all measurements were in line with directions)
less than 500 miles on tranny!

 

[chromedog]

with less than 300 ft/lbs, i wouldnt suspect the input shaft unless it was bad to start with my oe shaft has held up fine( 4000 miles this summer alone) behind a fairly stout 351w, i estimate 300 ft/lbs. there is a stock input shaft mod, but i think it only improves oiling to the direct clutch hub. thats the trouble spot for aods (ask me how i know) let me dig up some info, there are a couple different oe shafts, some being better than others.

 

[rbohm]

the inner input shaft is the one that carries the power to the 3rd/OD section of the trans. replace that and the trans should work just fine. the center shaft is not held in by anything except the torque converter and the socket where the other end fits.

 

[chromedog]

as promised, here is a little more on input shaft failure... the oe shaft is fine when used behind a nonlockup converter. the trouble comes when you use a lockup converter with a non hardened shaft.the best oe shaft will have a groove behind the splines to accept a hogring, but the ring has never been used.(the groove is nothing more than a round bottom relief running around the shaft.) as rbohm said, pop a new shaft in, and you should be good to go. it could have broken before the symptoms showed themself, as the input shaft does nothing more than drive the 3rd gear, and overdrive. i have a good shaft floating around the shop, pay the shipping, and its yours.

 

[ericl]

Thanks for the info guys

Chromedog
I sent a pm