jmix

So I've driven a couple hundred miles since installing the transgo kit along with pinless sonnax pistons, thicker separator plate, torlon *****, new solenoids and pressure switch, and corvette servo in my 00 silverado. Question is what could be making it shift hard? It kind of slams into gear but then there are times when it shifts awesome, nice and quick but not harsh at all. It almost seems like the line pressure is changing. It shifts hard more than not. I also have noticed the clunk when shifting at 20-25 with light throttle but I've read this can be common with 4l60e's. I've only had the truck a couple months and haven't driven it much because of the 1870 code (hence the kit) so it may have clunked before but I didn't notice. Another thing is I forgot to change the springs to what transgo recommended in their kit for the 1-2 accumulator. I worked on that last and just changed the piston for the pinless one and forgot to do the springs. I've read where some people say you shouldn't mess with the stock ones because it messes up the 1-2 shift. Is this correct so don't worry about dropping the pan and changing? Any help would be appreciated.

mrvedit

I don't know if the SK4L60e kit has the same 1-2 accumulator springs as the HD-2 kit (probably), but in any case those springs do not work with the Sonnax pinless piston. While I use the pinless piston for the forward and 3-4 accumulators, I use the HD2 springs with 1 washer and a stock aluminum piston. (I found the Sonnax shift kit 1-2 springs too soft.)

When you say hard shifts, are you referring only to 1-2 or also the 2-3?
How did you drill the separator plate?

I would suggest purchasing a trans pressure gauge on ebay for $45 (model ATD 5550). The hose is long enough that you can watch it through the windshield or side window while driving. That might help you determine why your shifting is something good and sometimes harsh.

jmix

All shifts. It's harsh most of the time.I drilled the separator plate exactly like the instructions.

For the 3-4 accumulator I used the transgo springs, is that not good? Also, stock the spring was beneath the piston and separator plate (viewing from underneath trans). Transgo said to there's between the piston and the case so I did that.

The gauge is a good idea (I've never used one) but it's rare that it shifted smooth.

mrvedit

Are you running a stock converter or higher stall? Higher stall soften shifts.
I doubt your 3-4 shift is too firm; therefore the Transgo spring will be just fine. And the Transgo position of the spring is better.

So, I think your line/shift pressure is just a bit high.
The Pressure Control Solenoid might be defective; did you replace that too?
Does the PCM have the stock tune?

jmix

I just got the truck and as far as I know it's stock tune. I replaced all of the solenoids but not all of them are oem. It was an ebay kit I bought with the wiring harness and all solenoids and pressure switch. I guess I could try another switch.

mrvedit

Your pressure switch is fine.
You could try another pressure control solenoid.; it is the one near the connector; you need to remove the 1-2 accumulator cover to replace it.

jmix

Meant to say solenoid, not switch.

jmix

And thanks for your help.