cat 936 transmission

hi all, looking at purchasing a 84 cat 936. Its been really well maintained and in quite great condition for its age. Only problem, I HAVE NOT WITNESSED is the guy tells me only on hot days when the machine runs for long duration, the transmission slips in 2nd gear. He says all winter long, no isses what so ever. That being said, worst case scenario and I dont make it threw the snow season, anybody have an experience with pulling the trans on these machines? I just rebuilt the trans on my 05...

cat 936 transmission

cat 936 transmission