# jd 4455 tran oil leak into engine



## FarmwDeere (Feb 10, 2017)

We can not find an obvious leak path for transmission oil getting into engine oil. The tractor is at dealer for repair. Leak amount was 1 qt. per 7 hours. Any suggestions on how to test or where to look? Thanks.


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## FarmwDeere (Feb 10, 2017)

*More information*

While engine oil was increasing the transmission oil was decreasing as determined by dipstick measurements. Oil sampling indicated no fuel or antifreeze in engine oil. Could a hydraulic leak flow oil into engine? Thanks.


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## EdF (Sep 15, 2014)

Hello FarmwDeere,

Welcome to the forum.

If you have an engine-mounted hydraulic pump, you my have a leaking shaft seal on the pump which could leak hydraulic fluid into the engine oil.

If you have engine oil cooling and hydraulic cooling sections in a common radiator, this could also be a source of the leak.


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## RC Wells (Dec 26, 2008)

The 4455 series John Deere tractors use a wet clutch (operates in the transmission oil), so the transmission oil is likely leaking past the rear engine main seal.

Your dealer's service department should know this. Problematic to fix, as it requires splitting the tractor. It is also a good idea to always park the tractor on the level or with the engine higher than the transmission to prevent the transmission oil gravity flowing past a worn rear engine main seal, and do not overfill the transmission.


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## FarmwDeere (Feb 10, 2017)

Thanks RC. We did a 24 hour parked test on a hill. We didn't detect a leak. However, I think the test was too short, used dip sticks versus draining and weighing, and sealing is different with rotation versus static. We gained 7 quarts in engine over 78 hours plowing and finishing. Is there a build up of pressure with the wet clutch on the 4455 series or just churning? We will look closely at the rear engine main seal after tractor is split. Hopefully we will see a defective seal that is definitive. Thanks again. All suggestions are appreciated.


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## RC Wells (Dec 26, 2008)

If the charge pump return filter is clogged that can push oil into the clutch housing. That is filter # R27173.

Been years since our last one was retired, very good tractor, probably one of JD's best ever. I do not remember if it had a vent on the transmission or not. I suppose one could pop the filler and see if it was under pressure when the tractor was operating and warmed up.

Actually wish I had kept the old girl and just spent the money to put in a new engine at 20,000 hours.

Used the last on on a sugar beet planter that had hydraulic accumulators, and if the three point was let down when the tractor was shut off then the accumulators dumped back into the hydraulic system and it would overfill the transmission.

I do know that the transmission fluid used is pretty much the same as 10-30 motor oil without the motor oil additive package, so it does not hurt the engine at all as long as routine oil changes are in accordance with the schedule.


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