I have a cat 930 that overheats linearly but has been happening increasingly more and faster. I checked all the obvious stuff like radiator, air cleaner etc to no avail then got the temp gun on it and it seemed like the transmission oil cooler was the hottest part of it, so I changed the transmission oil and changed the transmission oil filter. Still overheats, then I noticed bubbling coming from the radiator cap when it was at full noise. Thinking now it might be the head gasket? Any help or recommendations is much appreciated.
Serial number helps. You can get an exhaust gas test kit and see if the bubbles are from exhaust, indicating a head gasket issue.