so I assumed the service engine soon light was on for emissions but as it turns out its for slippage from 1st-2nd so said our mechanic when he read the code. Paul ssaid he thought the clutch pack was failing because of the specific code. however i looked at the tranny fluid and it barely clings to the dip stick so I'm assuming it just needs new fluid like mine did at around the same mileage mine had a similar issue with slippage on the 3-2 downshift and is now non-existant my dad said the only way he's switching it anytime soon is if i do the work (it costs no more than an oil change). but anyways i wanna save the car in time and if this is the only way then so be it i just was curious of where to buy the right fluid and any fill techniques/ where drainage fill points are and what tools i need. 3100 equiped special edition

 

All GM transmissions I've seen, there is NO drain plug. You have to loosen the bolts and "tip" the pan and that's how you drain it (no matter how hard I try, end result, big mess). You just need a socket set, filter (usually includes a new gasket). Once the pan is out, the old filter wiggles out. There is also a metal "seal" in the trans you remove and replace with the one that comes with the new filter. I typically use a flat head screw driver and hammer and lightly tap on one side of the seal (towards the inside of it) to collapse it and use needle nose pliers to pull it out.

To put the new one in, find a socket that the back side of the socket meets well with the bottom of the new seal (you can then gently tap on the socket with the hammer to get the seal in). Then the filter pushes in.

Clean the old pan up.

New gasket, bolt the pan up (I go "snug", I've never used a torque wrench). Also, when I'm on the final round of snugging, I skip every other one to try and get the pan evenly snugged.

Refill by placing a funnel in the trans dipstick tube (refer to owners manual for fill level, there are two, a trans rebuild and a trans fluid/filter change, which I think is around 7 quarts of fluid).

FYI - If the mileage is far beyond 100,000 miles, and the trans has never had fluid/filter change, for some, this has marked transmission death. Just be forewarned.

I have always changed my trans fluid at 100,000 miles. Never an issue (sold a car with 215,000 all original trans, it's still running and it's had a pan drop fluid change twice by me).