2001 GMC Sonoma Transmission slight whine. Need help

Hi I have a 2001 GMC Sonoma Highrider Edition it has the 4.3 Vortex and its 4x4 my transmission has been whining alightly it has 169,000 miles on it runs and shifts great it when’s when ever its in park and whins threw 1st gear from what I can tell but it doesn’t whine in Reverse from what I can tell. Any clues or information would be appreciated this is my first truck and I love it so far and Id hate for the transmission t

What you might be hearing is the sun gear reaction shell starting to give out. http://www.justanswer.com/gm/53jhr-gmc-sonoma-1998-sonoma-no-reverse-will-not-shift.html It’s part 670 in the diagram.

When these start to fail they whine at first. The transmission then loses reverse and/or first gear when it finally lets go.


Well I keep having people tell me it’s the front pump or I need to change the Filter and Fluid to Help the Valves out. It doesn’t get loud or anything it stays the same volume at a certain point cause I put it in park and listended to it closely