I recently sold my 1/2 ton Silverado for a 3/4 ton 6.0 with the 4L80E. With my 1/2 ton I could be cruising around in 3rd gear under 35MPH and when I stomp on it, it would slam into 1st without any hesitation and away we go.

Do the same thing with the 3/4 ton 4L80E and it will ALWAYS brieftly downshift into 2nd before going into 1st. I can never get it to go directly from 3rd to 1st at moderately slow speed.

Is this normal for the 4L80E to downshift like this as opposed to the 4L60E?

So nobody knows how their 4L80E downshifts from 3rd to 1st?

well I have the 4L80 but have never noticed the downshift being different than a 4L60. Guess with a 6.5 diesel I am just used to it not getting up and going when I stomp it. I can tell you these are two different trans and you probably have different gear ratios in the two trucks making the shifting more noticeable in the heaver truck. My guess is the 4L60 was going into 2nd as well and you just didn't notice it. I will try to remember to pay attention when I leave after work and see what I can figure out.

The 4L60 and 4L80 are to completely different anilal, they are not geared the same nor use the same style set-ups. The 4L60 is more of a light duty design, it was origanally built for the Corvettes and Camaros and then put in the trucks to get milage up. It has come along ways through the years and is a good tranny. But the 4L80 is an off spin of the turbo400 and is a truck tranny to the core. The only comparison I can make is my buddies 05 3500 with the 6.0 shifts nicely, I couldn't feel any overlap from first to third but it could have been there. So long as it shifts and holds the power don't worry about it, thats how I look at it.