Allis Chalmers 916 hydro problem..STUCK!

Hey guys, I have a problem with my 916h. First off, I got a 916 from my wifes grandfathers estate last week. It had been sitting in a barn for over 10 years and has had some parts removed over the years. muffler, carb, driveshaft, lift pump...but it has an almost new mowing deck he ordered for it, so that's a bonus!

Well, I thought i'd get online and find me some parts to make her come alive again. I lucked up and found another 916 tractor on craigslist a couple hours away. The seller said he ran it in the fall, but thought it needed a coil because there was no spark to the engine. i snatched it up for 200. i figured parts alone would cost me that elsewhere if I could even find them. Turns out his 916 was in alot better shape than mine so I quickly decided to use it and use mine as the donor tractor. About 2 hours of troubleshooting and finding a faulty safety, the mower starts great and the engine seems strong.

Here is my problem, I got it fired up, took a seat, went to go forward...nothing. It won't move. I then took apart the hydro release to make sure the plungers weren't stuck, checked fluid levels, ect. and still nothing. Also, before I got started, I couldn't get it to roll at all, one rear wheel will go one way and the other will go the other way. but can't seem to free up the rear end. The (drive pulley?) thats on the rear axle seems stuck. I removed the pulley and carefully put a wrench on the stem and applied a little pressure on it while my buddy rocked the mower back and forth and nothing. It doesn't seem seized, just like there is something not releasing.

Like I said, I have another 916, but REALLY don't want to swap rear ends if I don't have to. I still don't know why I can't get the thing to roll after pressing down on the hydro release buttons, or when they are in the up position. All the seals are good and the ball plungers inside them are working great. I primed/bled the hydro pump and I know its pumping. Makes me think it's not the release, but something in the rear holding it.
Sure could use some guidance, it's alot different than my zero turns!!

Thanks, Scott

Thanks

As far as fixing the current hydro, souds like moister collected in the unit and it rusted. Due to the clearances and continued contamination your wasting your time. Just swap out with the good unit.

 With the wheels trying to turn in opposite direction then the differential is working but the wheel motor is not releasing the hyd fluid generated by the wheel motor. 

 The button for moving the tractor relieves this pressure to allow pushing the tractor but sounds like a few more problems in the hydro section. 

 Just swap the full unit and hope the other one is good .  

Steve@B&B