I did my LS swap (71 C10, stock LM7) about 3 years ago. I don't drive the truck much as it's mostly a parts hauler, but as I'm driving it more the way the 4l60e shifts is bugging me and I don't know if it's a physical transmission issue, or transmission tuning issue. Transmission tables are stock on my tune (hp tuners). The issues I have are:

At idle (650-700rpm), when I put into drive the transmission is grabby. Like when I have my parking brake on, it'll push through it\creep a bit. It feels like the opposite of a high stall converter.
Putting the truck in reverse has the same issue, but also there's a bit of a delay before it goes into reverse.
All upshifts work pretty well from 1 to 4, but at part throttle going 40-50mph the transmission hunts gears a bit. It constantly want's to downshift to 3rd only to immediately shift back to 4th. Over 50mph this isn't an issue.

Some info about my setup:

Stock converter
Corvette servo
2000 Camaro ECU tuned for the 5.3.
My speed is calibrated for my diff and tires, the speed I see in HPTuners I've verified with GPS.
b&m shift kit
No DTC's related to transmission (I do have an O2 code I need to rewire my O2 sensors and replace them).

Honestly this is the only thing I have an auto in so it's a bit frustrating. Any advice as to how to go about troubleshooting the problems I'm having?

Clayton

 

Grabby? Not sure what you mean there. Reverse delays to engage? My guess is that you are low on trans fluid. At least I would check that first especially since you likely have a dipstick different than stock. The 4L60E Lokar universal dipstick in my 70 El Camino is almost useless to me for checking fluid level.

Rick

 

Struggling to think of a way to describe it. Like it's engaging too hard while at idle, it doesn't slip as much as any other auto I've driven at idle. The moment I let my foot off the pedal instead of slowing beginning to coast, it starts to move pretty quick. I'd say it acts like a high idle, but my rpm (as verified in HP tuners) is ~ 700rpm.

I am using a stock dipstick tube and dipstick.

 

Sounds like it might not be jumping into the idle in gear timing etc.

Check the in gear timing tables
Lower idle in gear some
Check idle airflow in gear vs park

There is also some tables to adjust for airflow when transition from park to in gear. Play with tht some.

If this is a stock engine combo i would set idle to 550-600 rpm. 700 is a lil high.

 

Download the blue cat trans calculater.

It will help big time with the shift points. Youtube has some nice videos of using it.

 

Lets get some line pressure readings... and have some numbers to base a recommendation from.

I used to see people trying to crank up the EPC solenoid way too much often to cheaply raise line pressure...

This can make for unpleasant park/ neutral entry and exit.