Gmt800 Transmission Shifting 1-2

[Forkster]

My GMT800 (below) has a weird shifting habit. If I'm accelerating slowly, the shift from one to two is quite noticeable. If I shift from one to two under harder acceleration, it's smooth as a baby's bottom. It now has over 130,000 miles on the odo but the 1-2 shifting is becoming more noticeable.

 

What would fix this?

 

a) Get a GM shop to see if there is a reprogram available.

b) Do a transmission flush.

c) Do a transmission drain and fill.

 

Or is thing something else? Tranny failing?

[jro909]

its normal...there was an update to ease the bump shift i think

[gmtech4]

+1 ,i read that at a tech site

[Forkster]

its normal...there was an update to ease the bump shift i think

Anyone know the TSB or reference for it? I'll need it for my dealership -they're a little slow on the uptake if you know what I mean...