John Deere 4100 Hydraulic question

[42FarmallMatt]

I have purchased a grapple to run on my John Deere 4100. I will be installing a hydraulic diverter into the curl/dump circuit to operate it. The problem I have run into is the sizes for the ends of the hoses on the tractor. The coupler seems to have 3/4 inch thread but I can't get it to thread onto my thread gauge. I will run the soft lines from the loader valve into the diverter valve and then out and back to the hard line mount on the loader. Anyone have any experience with this. My loader has 3/8 hoses and the grapple came with 1/4 hose and way to big of quick connects. I have no prior experience with setting up hydraulics. Any input and assistance is appreciated

 

[Jim.ME]

Are these the couplers/threads you are asking about in your other thread? There are no threads showing where the hose threads into the male coupler in your second picture. That looks more like O-ring boss or BSPP than pipe thread to me. NPT is tapered and generally there will be a few threads showing on the hose end that won't thread into the coupler.

 

[42FarmallMatt]

No that is just a coupler that hooks into the line for the loader valve under the foot plate on the tractor.