HelpforID

I did some searching but couldn't find any answers. so it's a 00' civic, AT, 256k

First question is I decided to check my fluids this morning and noticed my coolant was really low, but I added some and that's no problem, but when I checked the tranny fluid there was pink foam on the top of the dipstick when I pulled it out, the level was fine and I hadn't added any in the past 3+ months what could it be?

My other question is a little more difficult, the car will vibrate/shake pretty pretty bad right around 40 mph, but then stop when I get above 40. it just did this last night for the first time.

and finally when I was driving last night when the tranny shifts from 1st to 2nd, it shifts fine and then kinda hiccups and then remains running fine.

This has all happend in the past 24 hours, so hopefully you can help

Evs-One

When it vibrates/shakes....does it matter the RPM/gear? Cruising in 4th gear it does it? And say, accelerating at higher RPM in 2nd gear it does? If it does the same in both gears/RPM, it's most likely a tire balance/water in tire issue/general tire issue.

Are you checking ATF with engine running or off? Engine should be OFF, and sit for a minute before checking Honda ATF.

How low was coolant? any leaks? May need to bleed cooling system if it was super low...and do a rad pressure test to pinpoint any pinhole leaks.