Transmission (4L60E) hesitates when shifting from reverse to drive.

[GearShftr12]

So lately my K1500 Suburban hesitates when I shift from R to D. I recently added an extra factory tranny cooler (2 external coolers total). There is a small tranny fluid leak. The fluid levels appear full...but, I may be checking that wrong. This hesitation or slippage happens when the tranny is warm or cold.

[2500ak]

There is a known issue with the 4l60e which many shift kits claim to amend that can cause that.

Where is the leak coming from? If there is blockage or restriction in the cooler lines or cooler it can bleed out of it breather, its a tube sticking out on the on the top of the trans.

[GearShftr12]

I have to get under and check. So check above the tranny for the breather tube. And if it is leaking from there?

[2500ak]

That is definitely the first thing I'd check, there's usually a little spout off on the top of it with a rubber tube and hangs over the side. At least that's how it is on the 4L80e, I'd assume they'd have a similar mechanism on the 60e.

[GearShftr12]

I checked that rubber tube and appears pretty dry. Doesn't look as if any overflow fluid has come through there. While under there I think most of the leak is coming from around the pan. I plan to drop the pan and replace the filter, gasket and install a drain plug. Got any thoughts of what to do while I'm under there to help fix this problem? Shift kit?