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Case 1840 leaks oil from flywheel housing

Case1840BC ยท 2017-10-28 16:05

Hello everyone, I could really use advice how to proceed with oil dripping out from a 3/4" threaded hole in the bottom of flywheel housing. First thought was it is the main engine seal but then I realized it is the hydraulic oil because it is very clean compared to the diesel engine oil. If I got it right the oil from the tandem drive pump must be leaking around the splined shaft that slides into the splined coupler inside the flywheel housing. I searched the Case forum and so far I did not find anyone having similar problem so I am at loss what to do or how to fix it. The oil starts dripping as soon as the engine starts. I used an inspection mirror and saw few drops falling down from the hole followed by a short trickle, then nothing for a second, then again drops, trickle and so on. The skid steer moves no problem but going up hill it leaves an oily track behind and I have to keep refilling the hydraulic oil in the main tank. Did anyone had the same or similar problem and could share some ideas what to do? Thanks for helping

Replies5
  1. #1alrman2017-10-28 19:36

    Welcome to HEF @Case1840BC ! The pumps need to be removed from the machine & a seal at the input shaft needs replacing. While the pumps are out, remove the pump mounting plate & inspect the drive coupling bushes, they may need replacing. TIP - Give the whole work area a thorough clean before any dismantling happens - You do not want to allow any dirt or foreign matter into the hydrostatic system..... This job sounds very simple - but if not done correctly - it will cost you many thousands of $$$ to make right

  2. #2Case1840BC2017-10-31 03:12

    Thanks for the responses. It all started with the skid steer leaving oily track behind it when moving and the level in oil tank needing constant replenishing. There was lots of oil on the floor everywhere. Where all the hydraulic houses are crossing under the drive pump/ flywheel area the oil level was really deep because the hoses and dirt built a dam preventing the oil from draining out. After cleaning out all the mess and feeling the hoses I found all of them had spots worn out to the steel braid sharp as needles (made many holes in my fingers). So I thought the oil was leaking from the damaged hoses and I replaced them. Only after that, when the oil appeared on the floor under the flywheel housing area again I took an inspection mirror and saw hydraulic oil dripping from the 3/4" threaded hole in the bottom of the flywheel housing. Taking out the drive pump is not a big problem but to take it apart is where I don't think I have the right place and all the tools needed to replace the seal. Besides that, the information available from Case shows every detail and parts for the diesel engine, the valves and cylinders etc, only the drive pump is shown as a complete unit and no exploded view and parts are shown. For now I have installed right angle barbed fitting to the flywheel housing, attached 3/4" clear tubing connected to a plastic container placed beside the battery. The out tubing is hanging out through the floor cleaning floor hole with barbed fitting closed by 3/4" screw on cap so the oil it can be drained and measured. I want to find out if this is the last oil leak remaining at this time. If it is there should be no more oil on the floor anywhere. In the meantime if anyone can point me out where to get exploded view of the drive pump so I can get a part number for the seal and get some idea what tools I will need to take the drive pump apart, remove the old seal and replace it with a new one. Thanks for your help!

  3. #3alrman2017-10-31 08:03

    Here is is parts listing from the online Case parts catalogue. Probably best you invest in a service manual BEFORE doing anything too serious & follow the instructions very carefully.

  4. #4bartelbe2017-10-31 09:20

    no need to take the pump apart the shaft seal is retained by a snap ring simply remove and drill a small hole into old seal insert a screw and pull it out. inspect the shaft for any groving if not to bad install a new seal and away ya go. part # for seal is N14103 which will proabley supersed but dealer will get ya right one, easy job nothing to be scared about

  5. #5Case1840BC2023-12-19 12:31

    .....no need to take the pump apart...... I followed your instructions and the job wasn't difficult, just as you said. I was so happy that I forgot to respond to your message so please accept my thanks now, I still remember the relief when the oil stopped leaking around the shaft. Thank you!