Allison extension housing replacement procedure

[cm2500hd]

ok guys I have a cracked extension housing. I know I have to pull the trans to fix it but Im looking for more information on how to do it?
thanks

 

[JoshH]

Drain fluid
Remove transmission
Remove torque converter
Stand transmission with tail housing end up
With transmission in park, remove output shaft nut
Remove tailhousing bolts
Remove tailhousing making sure the park pawl pin doesn't try to come up with the tailhousing
Remove old tailhousing gasket
Remove C5 apply piston if your new tailhousing doesn't come with one
Install new lip seals on C5 apply piston
Install piston into new tailhousing
Place new gasket on rear of transmission
Install new tailhousing
Torque bolts to 42 lb-ft
With transmission in park, install output shaft nut and torque to 45 lb-ft
Stand transmission with bellhousing up
Measure input shaft end play (I usually shoot for around .035")
Correct end play as necessary with shim under output roller bearing
Lie transmission down
Install torque converter
Install transmission in truck

 

[Mike L.]

Josh, make this a sticky here. Save a lot of time and trouble for us.