Just bought an old d7 cat and cant find year or serial #. the track tensioners are bad and someone has rigged it and i need to find out the year and model so i can look for parts to fix the tensioners. any help is appreciated. i am new at all this. She runs and pushes but now the tensioners need fixed asap

There is two plaes where they are located & the main one is back above the drawbar toward the top on the steering clutch housing & if the plate is gone look for where twp rivets were drove in & they were always stamped in the housing. The second place is on the left side of the diesel toward the rear & below the head. If the two don,t jibe then probably the engine could have been installed from another tractor.For parts go by the one back on the housing above the draw bar.It possibly is a 3T serial number but could be earlier than that if from the earlier 40s.the next earlier would be a 7M SN.They came out in 1940 & the 3T came out in 1944 & ran till the 17A came in 1955.