856 transmission problem

I have a 856 that will not move with a load. When I let out the clutch peddle the tractor does not move for a second or two, then it will drive ok with no load. I put a new clutch in, I changed the trans filter, and I changed mcv pump(where I got the pump they only had the gasket to mount the mcv valve to the trans, so I did not take the mcv totally apart, but I did pull some off the springs and they seemed to be fine) It is the same with the TA lever forward or back. I thought the TA would not slip in direct. I added 5 gal hyd, it is a little over full. I pulled the filter thinking I may have pluged right away, but It didn't look pluged. The oil probbably could be changed but I dont think that is the problem. Any help will be appreciated.

If the low side of the TA (mechanical sprag) is good the tractor should move with a good main clutch. The high side (clutch pack)can slip due to low pressure from a weak pump or a leak. The only simple solution would be if the dump valve or its linkage is binding. The dump valve is the one connected to the clutch linkage with the 1/4" x long rod. Unfortunately when what you"ve described happens it is due to leakage inside the TA unit. If your power steering is working OK then you probably need a TA replacement. Many times guys don"t realize their TA is "OUT" on the low side because they will move a light load but not a heavy one.

Sounds like a bad ta.I had the same symptoms in a 856 this summer,slipping in high + low.Most of the time they don't slip in high but they can.Check your pressures in high and low just so you know where you are at

We really need more information to give you an answer that is not just a guess. It could be either the clutch or TA that is slipping.

What was the problem that made you decide to replace the clutch?

Did you have the flywheel resurfaced so that you have a true surface with the correct step for the pressure plate? Is all the clutch linkage adjusted correctly?

Does the steering work correctly at low idle? Do you have any problems with the brakes? Those two things will give a good indication of the condition of the MCV hydraulic system. Is the linkage for the TA spool valve adjusted correctly? Is the dump valve adjusted correctly and does it work smoothly without catching any place?

If you could furnish the answers to these questions we could give you a much better answer to what is probably wrong with your tractor.

Thanks for the responses. This is my friends tractor. My friend Paul had someone else do the clutch a month ago because of the slipping problem. The guy brought it back with something still slipping,and now wont talk to Paul. Paul thought he didn't do any thing to the tractor. Now being friends I end up spliting it, There was a new clutch but the trans seal was leaking oil between the two shafts, so I thought that was it. I put new seals in the nose cone of the trans. I got a new disk because that one was oil soaked and took the flywheel, disk, and pressure plate to the machine shop, they measured it up and said it was all in speck. I did reuse the pressure plate that was new a month ago. I cleaned the pressure plate and flywheel with break clean. Put it back together and it seems better but it isn't right. I have about one and quarter inch of free travel in the peddel, and I took the bottom cover off to make sure the through out bearing was not riding on the fingers. The dump valve linkage is not binding. I belive it is set right, with the clutch pedel released the dump valve linkage still has about a 1/8" of play. When I push the clutch pedel the light in the cab come on. The clip on the TA spool was up about 1/8" with the TA in high so I adjusted down a little. I did not adjust the trans break.    The breaks work good, but I think the steering should be better, I did some reading hear and thought the problem must be the mcv valve or pump,so I put a gauge on the mcv valve,It did not read at free flow,but my gauge goes to 5000 psi so there might of ben a little pressure. I turned the wheel to the right and held it and pressure only went to 1000 psi in the IT book it said it should go to 1900 psi. so we got a pump, and sill the same problem. I wont get back to it for a few days. I guess I should put a guage back on it. Maybe that dump valve isn't holding pressure???
When I let the clutch out, the tractor acts like it is in neutral for about two or three seconds then will start to move. if it is reved up it still has the delay then jurks in harder.   If it is moving in gear and I push the breaks it dies down the engine but I can stop the tractor. This is not very consistant. When I first start the tractor and did hold the breaks it will almost kill, Then drive it in the field for 5 min it bearlly wants to move it self. I know that is hard on things,and I have only done it a couple tims.I normally wouldn't do that.   

Check the rear axle hubs! I once had a customer drive in an 806 asking for a new clutch, but I noticed that the spline in the rear hub had sheared and the axle was turning inside it.

Sounds like the TA is shot.

Hydraulic TA will go out on both sides. Only the mechanical TA like on a 400 will continue to work on the high side when the low side goes out. Very rarely does a mechanical TA leave a tractor dead in the water.

Thanks for the information. I will check the hubs but I think its the TA. I was hoping it would be something else. I have done a couple clutches before but never a TA. Would it be possable to change the TA without splitting it again? I have done a little looking and I understand all the gears have to come out the top plate of the trans then the TA is last. I am assuming I have to split it. One thing I found the guy took the hole trans out, is that correct? The tractor has a cab. Any info is appreciated and helpfull, thanks again

I think the TA requires a "double split" even on the big tractors.

You need to split the rear end from the engine at the bell housing, then remove the TA section from the tractor.

As for what the guy did when he replaced your clutch, we weren't there so we have no idea.

It doesn't make sense to take the "(w)hole transmission" OUT of the tractor, unless the person saw the tractor split, and that's how they described it. Not everyone knows the technical terms, and they could see someone splitting the tractor as "taking the whole transmission out."

If in fact this guy did more than just split the tractor and replace the clutch, the question is WHY. It's an awful lot of work to replace a TA. Why would he go to all that work to remove a USED TA and replace it with a BAD TA, not knowing the condition of the TA he's taking out?

Sorry for the confussion. I ment when I was looking on the computer, how to install a TA. I found a spot with pictures, and that guy had split the tractor in two places. He had the trans out on the floor of the shop. I was hoping I didn't need to do that.
I don't think my tractor TA has been out yet, at least not for a long time.
Where you said I can split the engine from the the bell housing then remove the TA section. Does the TA come out the front? I thought I had to pull the gears out of the trans and the TA came out after the gears.
Thanks for the info.