JD 830 hydraulic pump replacement - stuck drive yoke

[Dan in North Houston]

Changing out the hydraulic pump on my 3 cylinder JD 830 utility tractor. How do you get coupler off the end of the shaft? It is a 3/4" nut, but there's not enough room to get a wrench on the nut. I took an old 11/16" wrench I had and ground away most of the outside and opened the jaws so I can get it on the nut. But there's not enough room to turn it. My next idea is to find an old 3/4" box end and grind it narrower so it might fit in - there's not enough room to get the box end over the nut. Then I need to rig some kind of puller to get the yoke off.
I had to pull the radiator and fuel tank to get this pump off. The hex rod connecting the pump to the crank pully might have slide back to allow disassembly when it was new, but there was no way it was going to move after being in place for 50 years - I had to drive it out with a punch when I finally got the pump out. If anyone has any hints on how to further get this pump off the mounting bracket, it would be much appreciated.


the

 

[Tx Jim]

When I was employed at JD dealer I never encountered needing to remove that nut. The tech manual I have for a model 2040 which has similar open center hyd pump has a photo utilizing a box end wrench to loosen/tighten that nut while securing hex drive shaft in a vice. I wonder if a ratcheting box-end wrench would fit in opening on drive coupler?

 

[used red MN]

If Houston means Houston Tx, then as most metro areas do I bet you can find a pawn shop or two. See if you can find another wrench with a thinner box end or as you say one you can grind down. Of course not being there it is hard to say but it looks to me like judging by the thickness of the nut that the photo shows a fair bit of space to access the nut with a box end. I can see where a ground down open end wrench as in your picture may not be ideal to get a nut off if it is fairly tight.

 

[Dan in North Houston]

When I was employed at JD dealer I never encountered needing to remove that nut. The tech manual I have for a model 2040 which has similar open center hyd pump has a photo utilizing a box end wrench to loosen/tighten that nut while securing hex drive shaft in a vice. I wonder if a ratcheting box-end wrench would fit in opening on drive coupler?

Tx Jim:
thanks for the response. It sounds like your tech manual has the same photo as the

manual for my 830. There's no room for a regular box-end, much less a ratcheting box-end. I picked up a cheap combination wrench today, and if I grind the box-end down to about half the normal thickness, it might fit. But if it does fit, it only will allow a few degrees of swing. I believe the only solution will be to grind the rivets off of the flex plate.

 

[used red MN]

If you get it broke loose but it is still turning stiff you might be able to use a needle nose pliers or a needle nose vise grip to turn it. I have a set of double open end angle head wrenches from Snap-on with thin heads that would probably get in there and turn it after it was broke loose, not everyone has that luxury. Believe me I paid for it, but they are nice to have especially to work on tractor hydraulic lines.