second gear

New member here - I've read a lot of posts here that have helped me figure out what may be the problem with my 2nd gen single-cab 1500 laramie, but I could use more personal advice. Long story short, I was an idiot and power-washed my engine bay (But hey it looks awesome), and now, it's sticking...

i have an "01 dodge ram 1500 4X4 with aprox. 145k miles on it, second gear went out not too long ago and i was told that it could be either the solenoid pack or the second gear band, i can fix both but i dont want to go blowing money i dont need to. any tips?