How much power can a stock tranny hold?

[NautiKev]

I want to add power to my truck and I'm planning on getting a BB tune, but how much power can my stock trans really hold. I don't have the time or money to rebuild one! Thanks!

 

[ATL]

from my experience, not even stock hp levels. i had to replace mine before the truck hit 100k, all stock!

 

[stevek]

from my experience, not even stock hp levels. i had to replace mine before the truck hit 100k, all stock!

A NNBS 4 speed can probably handle anything you throw at it short of some motor work (ie blower, cams, etc)

 

[johnsoex]

I have a 4l60e in my 08 and it lasted less than 2 mos with addition of a tvs 1900 on 12 pounds, methanol, long tube headers, intake, ported throttle body, and full exhaust (no cats). I'm guessing somewhere between 400 to 450 hp. Second and fourth gear went at the same time.

Its in the shop now getting a 4l80e, auburn rear diff and 4.56 gears. That should hold just about anything I throw at it going forward.

Ive heard the 6 speed is much stronger than the 4l60 but not as strong as the 4l80.

 

[HOE-N-IT]

from my experience, not even stock hp levels. i had to replace mine before the truck hit 100k, all stock!

I agree. Broke the sun shield/gear on my 02 at 22K. They may have beefed this part up though in later years since this was a fairly common failure.

 

[InTruckDesign]

Not that much at all...went thru a stock and built 4L60 in my full bolt-on '07 tahoe. Took out the forward sprag on the stocker and snapped the input shaft on the built one. The 6spd can handle alot more.