23 to 18 spline what it takes and how good i'll be!

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Fishracer66 said:
The splines on that broken 23 spline input shaft still look OK, despite the fact that everything else grenaded.... Does the 18 spine unit have a larger diameter input shaft too?
Click to expand...
Yes there bigger in diameter
 
I would suspect that the bellhousing broke first, allowing misalignment which broke the trans. If the trans just let go the bellhousing should still be intact.

Just sayin.....
 
d55dave said:
I would suspect that the bellhousing broke first, allowing misalignment which broke the trans. If the trans just let go the bellhousing should still be intact.

Just sayin.....
Click to expand...

I would agree with you. A broken input shaft should NOT have taken out the bellhousing like the pictures show! If the bellhousing snapped first from the torque, then the bearing retainer broke, then the input shaft was put into shear and snapped at the gear.

Just a theory. The cause is simple though. A WHOLE bunch of HEMI torque, probably twice what the stock gear was designed for!
 
"Does the 18 spine unit have a larger diameter input shaft too?"

18 spline is 1 3/16 inches while the 23 spline is 1 inch
 
Lets see 696 RWHP = ~ 900 Flywheel BHP. We know torque = hp at 5252 rpm, so lets say the power shift at 5000 was 85% of total engine output, thats roughly 780 ft lbs through the 833..

23 splines are very tough, and work behind some very strong big inch wedges. BTW, looks like the 23 spline input shaft was only one of the issues from the looks of the metallurgy.
 
Factory figured once you were at 500 foot pounds of torque, they would use the 18 spline input shaft.
 
It definitely looks like that bell broke and threw the input shaft out of alignment and then it broke. Not the trans fault. These transmissions can take a ton of abuse! I haven't broke one yet and I'm not easy on my stuff. 760Hp running in the 10's with a full weight car using a 18 spline.
 
Bell housings will break....with solid motor mounts as well....Did this 70 Barracuda run solid mounts?
One thing leads to another....weakest link will fail.
But...23 is plenty strong...800HP strong? I doubt it, for very long. Build a monster 800HP motor and leave a basically stock trans behind it?
 
I am going along with you guys that the bell housing was the
culprit there.
That is a big inch motor but I think it takes more than that.
I hate to add the weight of a Lakewood but always do and have.
The stock bellhousings just never looked strong enough to me.
I always indicated them in also.
I have never had or seen one come apart like what's pictured
and hope I never do.
That is scary looking for sure. Hope you get it back together and
it never does that to you again.
Thanks for showing us what can happen. A good lesson with pictures
for us all right there.
 
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