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@jeremy35
There is an adapter shaft (50) to drive the hydraulic pump - on the 855D it runs in a dry compartment (39), sealed (38) from transmission oil & the hyd oil.
The splines get very worn & it is obviously jammed up with interlocking worn spline teeth.
Get someone to rotate the engine back & forward a little while you try to pull the pump.
OR it just may be rusted in place.......
855D's eat those adapter shafts & pump splines because of this design.
1150's use exatly the same set up - but are wet, running in trans oil & the splines never wear out.
**TIP - You can modify it to be wet quite easily, & make the splines last much longer.
There is a tell tale drain opening in #39 plate - braze up that opening using a bolt / or some round or square bar as a filler & grind flat.
Eliminate seal #38
Eliminate expansion plug #51
Make a gasket for the front of the hyd pump.
First of all my guess is, you have to repair the problem you are currently dealing with
![855D hyd pump drive.png 855D hyd pump drive.png](https://www.heavyequipmentforums.com/data/attachments/299/299440-9e6ee77160e92afe16b97bde776ad5ec.jpg)