109 Hydrostatic will not move

[Buickguy]

I have a 109 with hydrostatic drive that will not move when I move the lever forward in reverse.

The one valve on top of the transmission was sticking and I removed it trying to free it up. I got it so the pin on top stays in the up position but the tractor still will not move.

Originally it almost feels like the forward and reverse are being applied together. Now nothing. Just like it is in neutral.

Does anyone know where I should be looking to see why?

Your help is appreciated.

[R Bedell]

Remove the tunnel cover. Pay attention to the coupler between the end of the Drive Shaft and the Input Shaft of the Hydro Transmission. Are they turning or revolving (RPM) at the same speed. Observe and report back.

[Buickguy]

I removed the cover and started the tractor. The input shaft that has the fan and the fabric joint is turning and where the joint couples with the input shaft with the roll pin also rotates. I can see the input shaft rotating.

I appreciate your help.

[ol'George]

What do you know about this GT?
Is it new to you or has it been working, and just quit?
The more history you can provide, the better we can help.
Going to the Dr and saying "I don't feel good" makes it difficult.

[Alvy]

Sounds like you should do new fluid and recommended filter. Inspect inside of rear after removing cover to drain

[Buickguy]

I will give you the best history that I can.

I have had this tractor for 40 years and for the most part it worked fine. For the last few years when I would move the lever for forward or reverse, there would be a slow start of movement on initial cold start up.

This last weekend the marginal engine drain plug failed and I needed to put in a larger drain plug. That fixed the oil dripping from the engine.

To move the tractor I pulled up on the lever that depresses the two valves on the top of the transmission like I have done hundreds of times to put the tractor into neutral.

Finished with the engine drain plug and tried to move the tractor and it would not move. Nothing, but then it jerked forward when pushing the lever forward. Some times it seemed that the forward and reverse was being engaged at the same time.

Same thing happened in reverse. I played with it a few times and then it started to work kind of normal.

I started cutting the grass and got about 1/2 way finished when it just stopped. I took off the cover to inspect the two valves and found the right valve pin depressed into the nut. I took the valve off and tried to clean it but it did not seem to help. I positioned it in he up position and reinstalled it. Still no movement.

I dragged it into the garage and now it seems to be in neutral.

As noted earlier the input to the transmission seems to working properly. The linkages on the left side of the transmission move.

I now have nothing.

Thanks for your help.

[J-Mech]

How long since you changed the oil and filter on the hydrostat?

[Jeff in Pa]

Originally Posted by J-Mech

How long since you changed the oil and filter on the hydrostat?

I agree with J-Mech's "hint". it sounds like you need to change the fluid and filter.

You will need the correct hydro filter and I highly recommend Hy Tran fluid. Yes it is a little pricy but it sounds like you got quite a decades out of the last fluid change.

[Buickguy]

I will do that tomorrow. Thanks for the suggestion. Hope it works.

PS: how many quarts of fluid?

[Alvy]

Originally Posted by Buickguy

I will do that tomorrow. Thanks for the suggestion. Hope it works.

PS: how many quarts of fluid?

7