I have a Komatsu D39P-1. Was working as should and 1st gear is now really weak. Moves forward and reverse slightly on flat ground but will not turn left or right, acts like its trying but won't. 2nd and 3rd everything works as should and pushes well and all other hydraulics work. Only issue is 1st. Any help on possible cause is greatly appreciated!
Sent you a PM with some information that may help
Thank you!