Hello to all gm lovers. I have a 95 monte carlo 3.4. I have a hard shift from 1st to 2nd. Replaced modulator. Issue still there. Currently changing all cooling lines. Replaced trans cooler lines which were leeking. Getting ready to install rack & pinion with tie rods and hub assembly. Before completing install I would like to check shift solenoids can this be done without dropping trans. Any input would be deeply appreciated. John 95 monte 3.4

Both the valve bodies & solenoids are subject to varnish build ups.
I would try to add a can of Seafoam Trans Tune and see if that helps smoothen the shifts out first.
How many miles are on the Monte now? If it is higher mileage you may want to just drop it down & rebuild it.
I believe you have the 4T60E transmission in you car.

Also check all of the vacuum lines to make sure you don't have a substantial vacuum leak, or maybe a collapsed vacuum line going to the modulator.

Also, how is the engine on power? If it is down a lot of power, this may be worthy of addressing as well. I have also noticed this behavior on mine when there is an issue that requires more throttle be used. And that is assuming there is no mechanical issues in the tranny as mentioned.

Thank you, It is a 4t60e transmission. I have drained the fluids during this current project. Trying to save a few bucks on fluids. Is there a port that I can check for continuity.

Engine power is great. Hot or cold this hard shift is there. From information gathered I'm leaning toward shift solenoid or vacuum. At this moment a few systems are down due to project. Looking for input on how to check these while project is going,

Stepping out to the yard in a few going to check vacuum lines. Would the amount of vacuum be affected if I change to rubber hoses with proper fittings. Thank for all the input from all the gm lovers.

Mileage is only at 90k. You are absolutely right on the 4t60e transmission. Looking for a port to check for continuity without dropping transmission.

This was a transition year between OBD1.5 and OBD2.
I know it may be possible to command the solenoids & TCC with a shop scanner.
I did find this video (with a robot speaking LOL) that has some applicable information.
Possibly other members can offer more information to help as well.

Thank you will watch the video again. It looks like this will guide me the right direction. Can I rent these scanners. I do have a multimeter. Im an electrician by trade. once again thank you. Any other ideas feel free to send info. Got to pay the bills so its on hold to this weekend.

YEAH I second that about the vacuum lines, I also have a 3.4L 2003, pull the PCV and shake, it should rattle EVERY back and forth motion. Mine would rattle for 3 or 4 and then nothing for the next 3 or 4 then rattle again, squirted some sensor safe carb cleaner in the bottom and dark brown fluid came out. also noticed the boot on top of the PCV was dried out and had a big crack, the seal that plugs into the top of the TB was falling apart so I replaced the whole tube, the other end I think goes to the EVAP that rubber tube looked ok, the new tube comes with everything needed. I replaced the other breather tube that goes from the back valve cover to the air intake, seal was falling off on the valve cover insertion point. If you use SEAFOAM, read the directions, I would not leave it in there for ever, just a few hundred miles - 1,000. make sure you get SEAFOAM for the trans and not gas additive. Could also be your PCS, unfortunately the PCS along with the shift solenoids can not be removed w/o dropping the trans.