Sundstrand Sauer Danfoss Series 90-55cc Servo Arm
They have changed the servo arm and swashplate on these axial piston pumps. The older parts you will no longer be able to get and there will be no way to interchange parts either.
The improved servo arm is a press fit that goes into a groove in the improved swashplate. You will need some different tooling to put together. So the on the 55cc, 75cc, and 100cc pumps you can get kits that are put together for these models. And these kits can go on older model pumps.
So the kit for the 55cc will have everything except for the S10 you see in the diagram below. The 75cc kit has everything in it. The 100cc kit has everything, except S10 & F20.
Also the slider block on the 55cc (F20) and the servo pistons on 75cc have changed just a little to account for the clearance for the improved servo arm. But the improved servo piston and slider block can work in the older models.
If you need more into on these improvements, give us a call at 800-361-0068