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Anyone else ever had a broken input shaft??

Lifted07

Full Member
Joined
May 5, 2011
Messages
295
Location
Winnipeg Manitoba, Canada
So asides from the lift, gears, tires and programmer my Avalanche is basically stock with regards to the engine, aside from it being brand new 1 year ago.  The trans is built with plenty of upgrades.  So my question is, has anyone else had the input shaft on their trans snap?  I have had the output shaft break already once and it took out the front pump and a bunch of other stuff at that time as well.  The trans was just rebuilt in January of this year under warranty due to the planet bearings going so everything was fresh at that time.  The shop said it snapped right at the journals (four cross drilled holes in the shaft for lubrication) but that it is VERY rare that they break.  The shop also stated that with the gearing I currently have in there (4:56) is better for the drive train than stock.  I wonder if with the shift kit, corvette servo and the programmer all bumping line pressure up and stiffening up the shift points is causing it, maybe I need to tune out torque management and abuse mode so that when it shifts under load it will break the tires loose rather than hitting as hard as it does.  Any ideas or input?
 
You should soften up the shifting to stop breaking hard parts.

When I first rebuilt my truck's transmission I had it chirping the tires on 1-2 shifts.  The output shaft broke within a week.  This was with the original engine (cammed).

After rebuilding it again I reprogrammed the computer to soften the shifts.  It now sits behind a 460 hp crate motor that I added a supercharger to.  It's been behind that combo for 2 years.
 
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