8psi+snappy 1-2 = broke output shaft
01-11-2010, 07:43 PM
#12
I broke 2, 4x4 output shafts. Both the same way and the only damage to the trans. These were GM, OEM, cryo treated shafts for 08 TBSS's (4l70e's i think). Snap!! 
Replaced the first with the second, then when It broke, I put a stock 2wd shaft in it and sold the tranny to a Fbody guy and runs 10's pulling the front wheels a it behind a NA 408. 
Replaced the first with the second, then when It broke, I put a stock 2wd shaft in it and sold the tranny to a Fbody guy and runs 10's pulling the front wheels a it behind a NA 408.
01-11-2010, 08:45 PM
#14
My LVL5 is at FLT right now because my 3-4 clutch pack wore out.Andy said everything else looked good inside.I've been running stock input and output shafts but I'm going to have them put a billet output in it while they have it.What is everyone's feelings on the input shafts?Do they need to be billet also?
01-11-2010, 11:20 PM
#15
12 Second Truck Club
iTrader: (7)
Join Date: Jun 2006
Location: colorado above 6000 ft.
Posts: 2,093
Likes: 0
Received 0 Likes
on
0 Posts
yep she took a crap. No hardened parts, I spent so much to begin with I figured it should be fine with the power I was making 
I think its the input shaft because I still have park, I think 
now I can't remember
Can a 4wd still have park if the output shaft broke??? I really need to pull it out and have a look. Is it common for the input shaft to break vs. the output.
I think its the input shaft because I still have park, I think now I can't remember Can a 4wd still have park if the output shaft broke??? I really need to pull it out and have a look. Is it common for the input shaft to break vs. the output.
01-12-2010, 01:56 PM
#17
yep she took a crap. No hardened parts, I spent so much to begin with I figured it should be fine with the power I was making I think its the input shaft because I still have park, I think now I can't remember Can a 4wd still have park if the output shaft broke??? I really need to pull it out and have a look. Is it common for the input shaft to break vs. the output.
I think its the input shaft because I still have park, I think now I can't remember Can a 4wd still have park if the output shaft broke??? I really need to pull it out and have a look. Is it common for the input shaft to break vs. the output.
01-15-2010, 10:31 AM
#18
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Jun 2002
Location: Oatmeal, TX
Posts: 491
Likes: 0
Received 0 Likes
on
0 Posts
Update: Truck is back together but cyl #7 is dead. When the shaft broke the motor overrevved and killed the DOD lifter Time to start tearing it down and put in non-DOD lifters on both banks.....
Time to start tearing it down and put in non-DOD lifters on both banks.....
01-24-2010, 06:05 AM
#19
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Jun 2002
Location: Oatmeal, TX
Posts: 491
Likes: 0
Received 0 Likes
on
0 Posts
update. Some info you guys might want to know...
When I pulled the 1900 off I found that the bottom part of each port on the spacers that go between the heads and the blower were blown out.
All eight of them. Not sure how fast this thing revved to but I did have my foot in it and the output shaft let go right at the shift about 6000rpms, so far more than that in a instant for sure.
Wonder how much boost it hit to cause the plastic spacers to burst
Cam, springs, pistons, lifter bore's all look good. Put in LS7 lifters and got the heads back on. Gotta wait and call magnacharger for a new set of spacers on Monday.
When I pulled the 1900 off I found that the bottom part of each port on the spacers that go between the heads and the blower were blown out.
All eight of them. Not sure how fast this thing revved to but I did have my foot in it and the output shaft let go right at the shift about 6000rpms, so far more than that in a instant for sure.
Wonder how much boost it hit to cause the plastic spacers to burst
Cam, springs, pistons, lifter bore's all look good. Put in LS7 lifters and got the heads back on. Gotta wait and call magnacharger for a new set of spacers on Monday.
01-24-2010, 11:01 AM
#20
12 Second Truck Club
iTrader: (7)
Join Date: Jun 2006
Location: colorado above 6000 ft.
Posts: 2,093
Likes: 0
Received 0 Likes
on
0 Posts
Mark, you see where both my output shafts are broke? I still had park AND reverse with them. I think the out put shafts break more then input shafts. Most of them break through the oil hole, like in the other pics in this thread. My first one, (the bottom one) was also cracked though the oil hole and you can see the twisting in the splines.