Aftermarket 310c john Deere hydraulic cylinder rebuild kits source

Hello,

Does anyone know of a good source for aftermarket hydraulic cylinder rebuild kits?

The front bucket dump single center cylinder on my john Deere 310c backhoe is leaking

Also, the swing cylinders are leaking too......



Instead of ordering from John Deere......how do I find a source on cylinder packing kits?

How do I match up the kit? Do I call join Deere and get the parts number and price and then translate that part number over to an aftermarket source like from Heavyquip or someone?

Or do I need to tear down my cylinder and measure things and then order from some random supplier?



Any tips?



I appreciate it!

Thanks