Yard Machine tractor, transmission trouble!?

[dart451]

I have a Yard Machine lawn tractor, 13A6695G118 w/tecumseh engine, OHV17 204605B. I have adjusted the linkage for this tranny so it will go forward/reverse. Works fine...then you drive it and cut grass for awhile and all of a sudden it won't go forward or reverse anymore! I cannot for the life of me figure out what's changing? When I first got the older tractor, it wouldn't go in reverse at all...but adjusting the barrel nut allowed me to get reverse neutral and forward. It seems to change by itself and I can't figure out why? Anyone have a clue?

[RoyM]

Does it have two belts connected by a variable speed sheave between the engine and transmission? It will be at least 10 years old with a Tecumseh engine, the belts or sheave could be worn out.

[KE4AVB]

Has Hydrogear hydrostatic tranny. One drive belt.

Check fluid level. With giving problem after heating up it probably internal leaks from worn parts. IPL doesn't list the model of the tranny so the OP needs to find its model number and see if it is one the serviceable units parts wise.

[wristpin]

Transmission moving on its mounts putting the selector rod "out of adjustment" ?

[dart451]

The tranny is due back at my shop today but it hasn't shown up yet. I will check the tranny...I have never checked the fluid on the tranny...thought they were sealed. KE4AVB, where does one add fluid and what type of fluid does it require? Thank you.

[wristpin]

The Hydrogears that I have worked on used a standard 20/50 engine oil.

[bgsengine]

The tranny is due back at my shop today but it hasn't shown up yet. I will check the tranny...I have never checked the fluid on the tranny...thought they were sealed.

They are. That particular transmission is sealed, no fluid check readily available - basically have to tear out the transmission in any event *some* of them have a plastic or rubber fill plug where you can check or add oil.
KE4AVB, where does one add fluid and what type of fluid does it require? Thank you.[/quote]
They are serviceable (Parts from hydrogear not from MTD) but odds are good, you need the slipper block and both valve blocks replaced - It is fairly common and probably cost almost as much to rebuild (depends on your labor rate) as to replace - The valve piston blocks run at about $85 each and the slipper block is something like another $65 , plus seal kit , oil, etc.

What usually happens with them as they wear (high hours) eventually they get slivers of metal working loose and when they catch in the holes in the valve block (Steel) and the slipper block (aluminum) it scores a small gouge in between the holes and oil leaks past there, so the transmission loses power - gets worse hot. - Heat makes the wear problem much worse, so it is important to clean the grass buildup on those transmissions like your life depended on it - they don't have much in the way of cooling fins, and also the cooling fan has a habit of hardening up and breaking the fan blades off.. no cooling = trashed tranny.

However, with some patience and a "not too deeply gouged" slipper block, it is *POSSIBLE* (couple hours of elbow grease) to refurbish the mating surfaces with 600 grit wet or dry paper on a piece of thick, perfectly flat glass (and lots of water) you can bring back that mirror polish and remove the gouges (even a half a thousandth depth of gouge will give you that problem) - if the gouges are any deeper than .002" , it's trash.

I used to refurbish SundStrand hydrostatic transmissions that way (re-polishing) but that was back when a new transmission was $900+, the slipper plates and blocks were $300+ , and labor rates were $25/hour.

[dart451]

Trannies are about 729.00...tractor isn't near worth that much! But I certainly thank you bgsengine for filling me in on this information! Looks like quite a procedure if you've never done it before!? I may just trying to change out the engine...put it in another craftsman tractor that is still good but has no engine. Course, not sure how the Tehcumsi engine will fit in the chassis though...that might not be doable!