S/N 6X408 This is one more of our fun projects. Going by the operator the levels stay good for several days or at least he doen't mention anything till it starts pushing oil out the crankcase breather. My boss talked to the service manager at the local dealer and says he was told only two possible areas. First he said to check is the transmission charging pump. If that is not the problem it would have to be the rear seal on the engine. Just wondering if anyone has other ideas. As some may recall this was the dozer that I had pulled a very dirty magnetic filter and strainer out of last summer. I'm thinking this would be one of the first things to check when I get to pull the pump to inspect the seal on the input shaft.
Don't know how the trans pump could be the problem. It's driven off the flywheel and doesn't have any connection to the engine oil that I'm aware of. Maybe if the torque converter is flooding and rear main seal is bad?
I believe that the pump is driven by a gear that runs in motor oil the gear that drives it is on the engine side of the seal. At least that is how the 3306's in the 966C loaders I'm familiar with are built.
If the torque is flooding bad enough the torque oil will push past even a healthy rear main seal. Torque temp. running high? The tractor will still push strong with a leaking converter, but will overheat converter.
Wish I thought I could get a straight answer from operator on something like that. I'm having Internet problems at home so can't check SIS. Does the converter get scavenged by the pump on the flywheel housing pump drive or is there a separate scavenging pump? I know there is a screen in the converter so that will be one of the things I check too. But have to do a major service on the D9H first and what ever else blows up in the morning!
Convertor has a scavenge pump down at the bottom and it has a suction screen by the drain plug. If you want to check out the convertor for leaks pull the drain plug put a 5 gal pail under it and stall the torque for one minute. Should get half a pail of oil. Later Bob
Kshansen,I'm thinking your first idea on the pump shaft seal is where I would be heading for.Had a D6C once that did that sort of thing when the lip seal wore grooves in the shaft.Used to just stick spare parts on from time to time from older D8 canabilised pumps.I had one D8 receantly that started making a nasty habbit of it.I put a couple of spare pumps on it and was starting to think of rear crank seals and other horrible things.TC simply took the pto housing apart one day and mentioned the bearings and everything else in the housing was abit tired.He replaced them with deacent ones that I had spare and it's been good for about 700 clock hours since(and counting) However,I'm not familiar with that series D6D so don't know how to help as it may be a totally different set up than my old D6C
I think the float on the shaft was causing the seal to weep due to the worn bearings