My '96 gmc yukon makes a grinding noise in reverse and first gear. Power is fine just the noise until it shifts to second an then no noise and no problem
First gear and/or reverse may be noisy: Either a torrington bearing or a planetary bearing is on its way out. Trans will eventually die a loud, catastrophic death. Cheaper to rebuild now (saves further damage to hard parts), but requires R&R. It is drivable until it breaks. Thank you for using fixya and good luck
Answers & Comments
First gear and/or reverse may be noisy:
Either a torrington bearing or a planetary bearing is on its way out. Trans will eventually die a loud, catastrophic death. Cheaper to rebuild now (saves further damage to hard parts), but requires R&R. It is drivable until it breaks.
Thank you for using fixya and good luck