Stuck in forward

[jimmyv]

Hey all! Hoping someone can help me here. I have a 91 Ford 2120 with 925 hrs. I had a brand new clutch put in last summer. Tractor really only is used to mow lawn with finish mower or brush hog occasionally. I recently hooked up the back hoe for a small digging job. After I was done with backhoe I parked the machine. The following morning, I jumped on and she wouldnt go in reverse. First thought rear breaks were locked up but raised all the wheels to check. They were fine. Seems stuck in forward. Any ideas?? Thanks.

 

[Soundguy]

12x4 or 12x12 tranny?

 

[jimmyv]

Hey thanks for reply. On the right of steering wheel there is 1 through 4 forward gears. On the left is forward neutral and reverse. I also have hi low and medium range. Shift on the fly. I believe it is a synchromesh 12x12 hydraulic shift shuttle transmission.

 

[jimmysisson]

I assume your shuttle lever moves through its full range of motion? Do you have the EHSS with turtle/rabbit?
Jim

 

[jimmyv]

It does. Had all the metal off to get a good look and be sure it was clean. I do have the EHSS.

 

[GMRDiesel]

I too am working on a 2120 W/ HSS. Had to split at front of main trans because of broken studs, due to too hard of loader use. Of course, had to split at rear of engine/ flywheel housing because of 1 bolt which ties all together from front. After reassembly, used tractor for about 2 hours functioning fully except once when it wouldn't seem to come out of forward. It Freed itself up after a few tries, then later- again locked up when I tried to reverse it. It now is stuck in forward, even when selector is in neutral, when reverse is selected- it locks up. Removed side covers & checked resistance on shift coils- both are 8.5 ohms. Seems to have power at 1 terminal for Forward on LH side coil, & power at 1 terminal on RH Reverse coil. Stethoscope revealed the RH coil energized for forward & reverse, But nothing on LH side coil. Just wondered if you had any resolution yet.

 

[jimmyv]

Hey. Nothing yet. Shift coils sounds like something I should look into. This machine only has 950 hours from mostly mowing. Very little loader or backhoe work. But the problem did start while using the backhoe. That led me to think fluid was low but no such luck.

 

[GMRDiesel]

Well- not an easy fix... turns out that when I removed the HSS valve completely, With absolutely no oil pressure to the HSS, it was still stuck in forward. Split again & found the forward clutches had lost a lot of their lining. The lining was broken into quadrants and slipped over the existing linings so as to increase the total height of the clutchpack which left it stuck in forward. I believe the cause was that the hyd oil had been contaminated with lots of moisture, ie. white fluid, which during the winter (-30deg), may have frozen- causing the lining to separate from the steel. The most unbelievable thing was the price for a clutch pack- over a grand! Did an added precautionary measure by installing a large vent cap on the fill plug, which hopefully will correct the moisture problem.