If you are referring to the Sundstrand Series 15 hydros used in several JD, as well as other brands of GTs, you have to go upscale from the TT K71 to find the equivalent. Mine has only given me one minor problem in 2500 hours that wasn't my own doing from tinkering with it on the bench.How does the Sunstrand 90/92 Hydro unit compare to the TuffTorq 71 and up? Reliable?
Tuff torq seems to still support their hydros with parts and service, is the same true for the Sunstrand hydro's?
Used replacements can often be found on ebay, and Sauer-Danfoss (the parent company) still supports them.
Sundstrand Series 90 hydros are used in 100+ hp farm tractors.