hey. got a caterpillar d4h LGP machine the overheats when walking slops or working on steep ground. can anyone tell me why? any detailed explanation? any detailed explanation of ways to check out the problems? what to look for? where and how to check pressures and what pressure to look for? does it have a transmission cooler? is it in front of radiator? does the transmission share oil with anything else like hydraulics or steering clutch housing? torque convertor failure? what do i do? any links to online technical advice on this machine? dozer is located in georgia.
Looks like the cooler should be part of the radiator (folded core). need serial # to be sure. I would start simple, pressure wash the radiator REAL GOOD, form both sides if possible. Make sure fan is moving air after you wash rad. Check fluid level and condition in transmission. Trans does share oil with torque con, and steering clutches/brakes. Verify that the oil is really getting hot. I like to use an infrared temp gun on the cooler lines while the gage shows overheat. If the trans or t/c are hot and both cooler lines are not, that gives you a direction to start troubleshooting. Not sure what your mechanical aptitude is or how you are equipped, a guy could write a book trying to cover all the possible problems. you may be ahead to contact a knowledgeable mechanic. He will be well worth what he charges you. Good Luck.
more please! thank you. i will look at it in that manner first. i have pressure gauges. and a friend has an infrared gun. so is the transmission cooler stacked in front of the radiator? or built INTO it? wouldn't i need to replace the cooler/radiator after rebuilding transmission so that i wouldnt risk contamination from the old contaminates in the cooler from the old transmission failure? i need to get the serial number. it is located away from where i am at the moment. can clutch fiber material from steering clutches...or clutch packs in the transmission clog up the cooler...or the valve body? thanks very much so far!
If your tractor has a folded core radiator, the radiator is made of a number of individually replacable cores, maybe 6. the trans cooler core will look like one of these cores. Yes if you rebuild a trans after a major failure you should replace the cooler. If you suspect a major failure, a very good troubleshooting procedure is to inspect the magnetic oil screens and the oil filter elements for debris. There should be 2 screens in your machine, one at the bottom of the torque con housing and one at the bottom rear of the trans housing. they are usually behind a small 4 bolt cover. You will want to drain the oil from the transmission before removing. If you want to really get deep into this thing yourself, I would really recommend scoring yourself a service manual!
Put a gauge on the torque converter, if it doesn't reach 42psi it wont send any oil to the cooler.
my old d75s had that problem. engine didnt run hot but found the fan belts were just loose enough to not move enough air. found it by accident. alternator went out replaced it and with tight belt trans temp went down.
I saw this same problem on a D5 LGP. Every time they would work a slope the machine torque converter would overheat. Radiator and cooler were all clean. Problem turned out to be the front sprocket bushing/bearing was worn and the idler was dragging. Field mechanic replaced the rear and front sprockets along with the front support. On this dozer the pins, rails and chain were also almost gone but this particular owner believed in running everything to destruction. Dozer seemed to work fine on level ground...hard to believe that the operator didn't notice any difference in operation with just one front sprocket worn.
ointhead seen simular problem on d5m drag on shoe guideswhith sloppy idlers
similar problem also on a D4H! The oil cooler on my D4H is in the radiator. I removed the rad and had it flushed, and replaced both lines to it. Had the CAT man out to set the pressures (they were good already). Decided to completely overhaul machine. I rebuilt the engine, and put new bearings and seals in both the transmission and torque converter. As I was putting it back together I noticed a dent in a steel oil line. It turned out to be the main return line from the filter to the housing. It was just enough restriction to keep the oil from flowing enough to keep it cool. Now its a GREAT running machine.