Sundstrand transmission help needed!

[Brian33 4]

Hello, 

 

I am hoping someone can help my. I recently acquired a c160 for the engine for another tractor. So I did a motor swap and wanted to see what the hydro was like. I put a plow on it C-160 (which now has a 12hp engine on it). I did a quick test run and everything was good. I drained the fluid and change the filter (Napa 1410 filter and sae 30 transmission fluid as it stated to only use this fluid on the tractor.) everything was working great after the fluid change. I plowed two driveways and the sidewalks near my house... all the sudden the tractor would not go forwards or in reverse. I tried to pick the plow up and nothing... I checked my drive belt it was turning like it should. I started to push the tractor and the rear was engaged so it would not move. Of course I was 400’ from my driveway and the plow was down which made it fun. I put the tractor in forward and started to push it and the thing took off. So I hopped on and took it to the front of the garage. I put it in revers and it cut out again so I pushed it in the garage. Today I went out to check the tow valve. I took it out and cleaned the threads up put it back in and it did not change anything. According to the dipstick I have the proper amount of fluid in it. I did have a drip that I fixed on the cylinder still nothing... does anyone out there have any tips to help me out? I’ve never had a transmission like this only manual transmissions. The model of this transmission is the sundstrand 90-1140.

Any help would be greatly appreciated.

 

Brian

Edited February 9, 2020 by Brian33
Added tags to posting

[Sparky-(Admin) 21,403]

The K series motors require straight 30w but I think the proper motor oil is 10w/30 or 10w/40 for the Sundstrand hydro. Maybe that straight 30w is to “thick”?

[953 nut 55,746]

Considering the fact that you were able to get it to perform properly I don't think the 30 weight is THE problem, though it could have been a contributing factor. The sudden nature of the failure and the subsequent restoration of full function sounds like a relief valve stuck open and was jarred closed by pushing. The improper oil could have contributed to it or it could have been a piece of trash got stuck and became dislodged. I would suggest changing to 10 W 30 and staying a little closer to the house for the first couple test drives.

[pfrederi 17,865]

What color was the fluid in the transmission. you said SAE 30 transmission fluid...Trans fluid normally doesn't show a weight.  If it was red it was Automatic transmission fluid if it was tan it was motor oil.  Either one is correct but you do not want to mix them  If you added 30w motor oil to a tranny that had ATF in it that may be a part of your problem.

[Brian33 4]

1 hour ago, pfrederi said:

What color was the fluid in the transmission. you said SAE 30 transmission fluid...Trans fluid normally doesn't show a weight.  If it was red it was Automatic transmission fluid if it was tan it was motor oil.  Either one is correct but you do not want to mix them  If you added 30w motor oil to a tranny that had ATF in it that may be a part of your problem.

It’s Napa brand sae 30 transmission oil. Do not know what was in it prior as the fluid was pretty low. I went with what the sticker said... should I try to drain the oil again and add the sae trans fluid? I was researching this a lot over the past week someone said there is a screen also referred to it as “mesh” but I could not find anything that told me where that was. If the kid I got it off of had motor oil in it and if I inadvertently mixed them what should I do?

 

brian

 

[pfrederi 17,865]

I am not familiar with NAPA trans fluid 30w.  Decide if you want to use ATF (Dex Merc) or 10w-30 motor oil, either on is OK just not mixing them.  Completely drain the system refill with your choice run for a bit then completely drain and replace again changing filter each time. You have to pull the hydro pump and motor to access the suction screen.   Hydro manual can be downloaded here.

 

 

 

[Brian33 4]

15 minutes ago, pfrederi said:

I am not familiar with NAPA trans fluid 30w.  Decide if you want to use ATF (Dex Merc) or 10w-30 motor oil, either on is OK just not mixing them.  Completely drain the system refill with your choice run for a bit then completely drain and replace again changing filter each time. You have to pull the hydro pump and motor to access the suction screen.   Hydro manual can be downloaded here.

 

 

 

Ty! This manual is way better then the one I have. The one I have can barely see the pictures... I will try changing the fluids out a few times and see if it clears up. Thank you for the advice.Napa 30 is dex apparently they are the same thing.

 

Brian

Edited February 10, 2020 by Brian33

[Brian33 4]

So today I changed the fluid and filter and same thing is happening... any thoughts?

[pfrederi 17,865]

If the lift fails at the same time as tractor refuses to move then acceleration valves or charge pump relief valves are suspect.  If the lift works but the tractor won't move it could be the plate on the left side of the tractor at the end of the motion control cross shaft had broken and allows the motion control to slip some times.  Circled in Blue.