Normal transmission shifting (What Is)

[blugrasslimos]

What is the normal speed for the transmission to shift into overdrive. I think mine is messed up, I drove a 09 and it shifts into overdrive at 40 mph,, and I have an 08 and it dont shift into overdrive untill 50 or 55 mph ,, NO LOAD.. just curious to what everyone elses is doing.. My dealer told me it has the latest update and they think it is normal. What do you guys think?? I think if it shifted earlier it would get alot better fuel miledge.

[Greenhorn Diesel]

Originally Posted by blugrasslimos

What is the normal speed for the transmission to shift into overdrive. I think mine is messed up, I drove a 09 and it shifts into overdrive at 40 mph,, and I have an 08 and it dont shift into overdrive untill 50 or 55 mph ,, NO LOAD.. just curious to what everyone elses is doing.. My dealer told me it has the latest update and they think it is normal. What do you guys think?? I think if it shifted earlier it would get alot better fuel miledge.

The trannsmissions in these trucks have adaptive learning. Your 08 is used to how you drive it. The 09 doesn't have a clue, because of it being test driven. Is the gearing the same between the two trucks? That could make some difference. I don't think anything is wrong with your truck. Mine does it at around the same speed as yours. If I am really gentle with it, it will shift into OD around 40 ish mph. Normal accel OD shift is the same as yours.

[blugrasslimos]

No both these trucks have the same gear ratio ,, I dont know maybe im dreaming up sh##, it just seems like it should shift into overdrive earlier. I have drove more than one 09 and they all shift at 40 mph,, just have not drove another 08.

[Greenhorn Diesel]

Originally Posted by blugrasslimos

No both these trucks have the same gear ratio ,, I dont know maybe im dreaming up sh##, it just seems like it should shift into overdrive earlier. I have drove more than one 09 and they all shift at 40 mph,, just have not drove another 08.

Have you got the latest reflashes for your truck? What job# is your truck? It could just be the trans strategy for your build of truck. Other than that

[blugrasslimos]

Yes it has the latest flashes , dont know what the job # is ,, my truck has 3.73 gears though

[Greenhorn Diesel]

Originally Posted by blugrasslimos

Yes it has the latest flashes , dont know what the job # is ,, my truck has 3.73 gears though

Job# is the build of your truck. Mine is a delivered Job 1 ( build date April 14, 2007) I am not sure what range of dates are the Job2 and job3, maybe someone can chime in on this.

[bradranger]

I have 3.73 gears also and it shifts into overdrive at 50 mph. Normal!

[SCUFFY828]

when trans shifts is no set speed , shifting is determined by load , throttle position , and rpms , lighter the load faster the shift , heavier the load longer the shift

[wontonrunner]

My 08 Job one with 35's and 3.73's stock shifted religously at 80kph on the nose unloaded and normal driving. Under heavy throttle/wide open it would not shift until around 75mph.

[bockhold]

Originally Posted by SCUFFY828

when trans shifts is no set speed , shifting is determined by load , throttle position , and rpms , lighter the load faster the shift , heavier the load longer the shift