Sundstrand hydro gear Transmission

[McTurff 1]

I posted a while back on the Jacobsen 1200 super chief I acquired and received some useful items

Thanks

Can't find where to place my inquiry so hope this is OK this is the only forum that I can seek some useful information!

I got the back end off the ground and the wheels will turn but only in opposite directions!

I can move the shifter to neutral and forward and back but cannot turn the control arm that is supposed to actually let the wheels come out of gear I guess they should move together as a locked diffential?? I removed the drain plug to look at fluid and it looks surprisingly good and no metal on the plug I think they are magnetic?

Also there was no metal in the fluid that came out i did not drain all the fluid was just doing some investigative work!

Anyway before I start removing axle and Transmission to go deeper and possibly open it up was just looking for any other tests I can try or look for!

[953 nut 68,112]

Here is a link to all of the Sundstrand manuals on this site, hope it helps you.

https://www.wheelhorseforum.com/search/?q=sundstrand&quick=1&type=downloads_file&nodes=24

[Bar Nuthin 2,920]

12 hours ago, McTurff said:

I got the back end off the ground and the wheels will turn but only in opposite directions!

 

That's normal - as it should be

 

12 hours ago, McTurff said:

I can move the shifter to neutral and forward and back but cannot turn the control arm that is supposed to actually let the wheels come out of gear

 

A hydro transmission would have motion control, not a shifter. There is no neutral, only "stop". Somewhere on the transmission should be a " tow valve" that can be opened to allow the tractor to be free-wheeled (pushed/towed)

[McTurff 1]

1 hour ago, Bar Nuthin said:

 

That's normal - as it should be

 

 

A hydro transmission would have motion control, not a shifter. There is no neutral, only "stop". Somewhere on the transmission should be a " tow valve" that can be opened to allow the tractor to be free-wheeled (pushed/towed)

Yes that lever moves back and forth fine forward neutral reverse!

The tow valve or control valve which allows the transmission to go into neutral and be pushed is stuck or froze up!

I did find a discussion searching different forums that others have experienced the same problem from a machine that has been sitting outside for years!

They were able to spray some pb blaster or other to break the control shaft loose! They were all stuck pretty good!

Hoping I get that lucky 🙏 

Thanks!

Edited 9 hours ago by McTurff

[CRF857 485]

It took months of soaking and tapping, but my tow valve finally broke loose.

 Be patient and don’t force it too soon.

 I keep it “exercised” regularly.

[McTurff 1]

11 minutes ago, CRF857 said:

It took months of soaking and tapping, but my tow valve finally broke loose.

 Be patient and don’t force it too soon.

 I keep it “exercised” regularly.

There is a nut holding shaft i read that others with this problem unscrewed the nut and we're able to get pb blaster down the shaft a bit easier?

Anyway i will start this process!

[McTurff 1]

Success!!!!!

I don't know if it was PB Blaster or Sea Foam Deep Creep but the Tow Valve is freed up and the wheels turn very smooth!!

Now I will drain transmission and refill!!

What gear oil should I use??

This is amazing now I can get it in my shop to work on engine probably a rebuild but I think it will be easier than transmission!

Thanks for the responses!

 

[pfrederi 20,987]

Different tractor manufactures all used the Sunstrand hydro gears and many had different fluid recommendations.  JD wanted you to use JD20  Some went with ATF  others motor oil some hydro fluid.  You might want to see what Jacobsen recommended  If it is pink or red probably ATF

Edited 3 hours ago by pfrederi

[McTurff 1]

55 minutes ago, pfrederi said:

Different tractor manufactures all used the Sunstrand hydro gears and many had different fluid recommendations.  JD wanted you to use JD20  Some went with ATF  others motor oil some hydro fluid.  You might want to see what Jacobsen recommended  If it is pink or red probably ATF

This transmission does not have ATF in it currently 

Ooops Have only opened the Differential! its gear oil

Edited 2 hours ago by McTurff

[McTurff 1]

51 minutes ago, pfrederi said:

Different tractor manufactures all used the Sunstrand hydro gears and many had different fluid recommendations.  JD wanted you to use JD20  Some went with ATF  others motor oil some hydro fluid.  You might want to see what Jacobsen recommended  If it is pink or red probably ATF

I haven't oppend the pump yet so that is probably ATF

would be the same as the Ford 120 tractors as the Jacobsens 1200 and Ford are basically  the same!

Anyway from what I have researched  as I am new to all these types of machines!!

Guess i need to open the pump to see what comes out!!

Thanks pfrederi

 

[pfrederi 20,987]

Originally would have called for Type A ATF (early Dexron)  Most of us use DexMerc

 

[McTurff 1]

5 minutes ago, pfrederi said:

Originally would have called for Type A ATF (early Dexron)  Most of us use DexMerc

 

OK

That's what im seeing from my reading other posts!

And gear oil or gear lube for differential 90w?

Hopefully the pump looks as clean with what comes out as the diff

Thanks

[oliver2-44 11,655]

1 hour ago, McTurff said:

This transmission does not have ATF in it currently 

Ooops Have only opened the Differential! its gear oil

The Sundstrand differential and pump used the same fluid. The pump pulls from the differential reservoir 

I use Mobil 1 10w 30 or if they are a little tired, 10w40 in my Wheel Horse Sundstrands

I recently been looking into the Walmart synthetic, I read people say its Valvoline, good price,  I probable will try some

Edited 1 hour ago by oliver2-44