[travlin-man]

I just boldly went where I can't find a record of anyone going before!
I just swapped the transmission from a C 161 to a 312 A.
I bought the C161 with a blown engine just for the purpose and the Sundstrand was almost a direct bolt in replacement for the Eaton 700.
I had to block off the two ports for the hydraulic lift and do a slight modification on the brake rod hook up and use the small actuator ball from the hydro cross shaft from the C161.The 312A had the hole already drilled for the ball in it.Also had to change the belt as it was too short on the 312A
as the Eaton had a 5in pulley and the Sundstrand had a 6in pulley so used a 82in belt instead of 81in. I know someone will want pics but I don't have any way to take any or the knowledge to post them if I could.
But the swap can be done I just did it!

I swapped the complete differential as an assembly just for clarification.


TM :thThumbsU

 

[TUDOR]

The pulley ratio for a Sundstrand is 1:1 with the engine.

Depending on which type of Sundstrand (there are 2 used in GT's), blocking off the implement ports may not be the best of ideas without doing another mod. Connect a short, pressure rated, hose between the 2 ports.

The Sundstrand service manual.

You will find that the tractor has a higher speed with the Sundstrand.

 

[travlin-man]

Thanks for the link to the service manual.
I failed to see anything in the manual about the mod you are talking about
though.I think I read something about it somewhere else though.
According to the pics in the manual the one I have is a type U.
I was and am amazed everything was almost a direct bolt in replacement
and trans seems to be working flawlessly although a little more jerky than the burnt up Eaton 700.

TM

 

[TUDOR]

There is another publication that covers the charge and implement relief valves in more depth, but Sauer Danfoss changed their name to just Sauer and the link was broken.

JD uses a shock absorber on their hand controlled type U hydros to kill the jerkiness of rapid speed and direction changes. My MF1655 with the foot control has the inline type that, unlike the U type, has acceleration valves built in to beat the problem. It is silky smooth.

 

[travlin-man]

I went ahead and did the modification using a hose from the lift mechanism from the C161.It was about a foot long but I just tucked it in behind the hydro pump being careful not to put a kink in it anywhere.
I do notice a smoother non jerky operation of the hydro now since the mod.


TM

 

[TUDOR]

The way you had it, the charge pump was supercharging the hydro with implement relief pressure (700-1000 psi), instead of charge relief pressure (70-175 psi). The charge system is the only circuit on a GT under continuous relief pressure due to its purpose of replenishing fluid in the hydro.

Most operation of the hydro will not be at implement relief pressure and the effect of supercharging is as you noticed, immediate response with no ramp up to working pressure.