98 astro tranny problem
 

Hi everyone,

I've got an astro that won't shift out of 1st gear unless I take it up to about 20mph and let off the accelerator. When I'm driving at around 30-40mph and accelerate it drops down in to 1st gear. I was told I probably need to change the filter and fluid because the fluid is brown and I don't know if it has ever been changed. It has 195,000 miles on it. Just wondering if I'm looking at a huge problem here or if a simple fluid and filter change will do something for it. Thanks for any help.