875 Problems

[KC9KAS 4,741]

Last week I tightened the 2 screws that hold pressure on the plastic piece that holds the trans in a constant speed. I also had the belt guard off.
I thought that I had the belt riding below the guide instead of on top of the guide once the guard was re-installed, as the belt was rubbing & smoking.
The tractor would barely pull itself on level ground and I was about 1/2 mile from home.
My wife pulled me home with the B-80. I had the engine running wide open and motion control full forward. The pull strap actually had some slack in it most of the time, so I don't think pulling the 875 caused a problem...I could be wrong...
I bought a new belt, installed it and it still barely pulls it-self. Everything seems to be tight and working like it should.

Any help in trouble-shooting this issue is greatly appreciated!

[953 nut 55,198]

The "Tow Valve" is closed isn't it?

[KC9KAS 4,741]

The "Tow Valve" is closed isn't it?

I have mowed with this tractor for 2 years and have not found the tow valve, so my guess it is closed.
I see where the tow valve should be but there is a plug in the spot and not a "TEE" or "slot" to turn anything.

[wfrpalm 218]

The valve is on the trans opposite of the pulley and facing the rear, it is a nut that is be loosened with a 1/2" wrench               ( about a 1/4 turn) to tow the tractor or make it free wheel. It should be only snugged when tightening. If it is loose now that is the problem. 

[stevasaurus 22,724]

KC, check page 5 in this manual.  It is actually a 1/2" head bolt that is pointed at the end to open and close the valve.  I know you have an 875, but it is the same as my 876.  Took me a while to find mine also.  The manual explains the valve.    It is on the pump between the pump and the trans on the left side of the horse.
http://www.wheelhorseforum.com/files/file/562-tractor-1966-876-da-om-ipl-wiring-snpdf/

[squonk 41,079]

If Ken has mowed for 2 yrs. and hasn't found this valve yet I think it's unlikely that the valve is now open.I'm thinking a hub key or the trans has given up. Do you feel any resistance in the hydro lever? When my hydro went the pressure build up forced the hydro lever back to neutral. It turned out my hydro motor was bad. The pump built up the pressure but the motor would not let it flow causing it to have too much pressure.


Here is another thought,The motion control arm where it connects to the trans has an allen screw locking it to the shaft on the hydro. Maybe when you tightened the plastic cam, it is now too tight and that arm is now slipping on that shaft. If it slips you can move that lever forward but the shaft on the trans doesn't move. That could be why you tightened the plastic cam? Before my hydro went that allen screw fell out of my C-160 and I had erratic speed control. Someone got in there before I got it trying to correct a problem and made things worse by playing with that screw.

Edited August 31, 2015 by squonk

[KC9KAS 4,741]

KC, check page 5 in this manual.  It is actually a 1/2" head bolt that is pointed at the end to open and close the valve.  I know you have an 875, but it is the same as my 876.  Took me a while to find mine also.  The manual explains the valve.    It is on the pump between the pump and the trans on the left side of the horse.
http://www.wheelhorseforum.com/files/file/562-tractor-1966-876-da-om-ipl-wiring-snpdf/

I think the seat has to be raised and you get to this through a hole in the front of the "tool" box. Mine is actually an ALLEN head, and it is tight enough that I couldn't easily move it, so I didn't.

If Ken has mowed for 2 yrs. and hasn't found this valve yet I think it's unlikely that the valve is now open.I'm thinking a hub key or the trans has given up. Do you feel any resistance in the hydro lever? When my hydro went the pressure build up forced the hydro lever back to neutral. It turned out my hydro motor was bad. The pump built up the pressure but the motor would not let it flow causing it to have too much pressure.


Here is another thought,The motion control arm where it connects to the trans has an allen screw locking it to the shaft on the hydro. Maybe when you tightened the plastic cam, it is now too tight and that arm is now slipping on that shaft. If it slips you can move that lever forward but the shaft on the trans doesn't move. That could be why you tightened the plastic cam? Before my hydro went that allen screw fell out of my C-160 and I had erratic speed control. Someone got in there before I got it trying to correct a problem and made things worse by playing with that screw.

Hubs are tight. The motion control arm that moves the shaft appears to be tight....I can see the shaft rotate side to side when the motion control lever is moved.
It was very low on fluid, although it didn't have any major leaks. I check it regularly, but it now was really low. Still have problems after refilling with ATF.