# Ariens S-12 Hydrostatic



## film495 (Nov 1, 2013)

I was swapping the filter on my hydrostatic transmission, first time I did on this tractor and not sure when it was done before, so I syphoned off a little extra of the fluid and ended up adding about 2 quarts of 10W-30 to top off including what was added to fill the filter before putting it in. So, I knew the park lock needed to be fixed anyway, but after I changed the filter and topped off - the machine now creeps forward slowly. I have the manual to adjust it, but found it curious that 2 quarts of oil and a new filter could have an immediate change. I don't really know anything about the transmission or pump etc, but figure the new oil added to the mix is making it easier for the pump to generate pressure? It was only 2 quarts, and I'm not sure how big the resevoir is, or what percent of the fluid is new vs. old. Possibly someone has some insight.


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## bellnygreen (Aug 4, 2007)

It sounds like more of an adjustment issue. Double check your specs for fluid levels etc. You have a good little machine there but I'm not all that familiar with the Ariens line. On my old Case 446 they recommend reservoir level be 4-6 inches below the top of the tank to allow for expansion.


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## film495 (Nov 1, 2013)

Basically there's 2 forks that face one another horizontally. The right fork moving front and back is the forward/reverse, and in neutral the control lever can be moved to the left into the other fork and pulled back to initate a lock/park in the transmission. I adjusted the neutral position at the cam slot in the shift mechanism, and it hits neutral in the right position now. It does however seem more sensitive than before, meaning the range of motion in the forward/reverse slot is smaller for neutral, it will creep a hair forward or reverse if the fork isn't shifted exactly. It didn't do this before, I do wonder if I slightly overfilled the hydrolics or if it's just become a little livelier with the fresh filter and a little new fluid. It's possible that it was a little low before too.


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## film495 (Nov 1, 2013)

Doing the maintenance, I found the transmission needed about a pint of oil to top it off. If this normal or do I need to track down a slow leak someplace.


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## bellnygreen (Aug 4, 2007)

Glad to hear your pulling some maintenance. That means your getting some seat time and operating that old Ariens. A full pint does seem excessive, but it could also be how hard the machine was used and even the amount of time it sat before you purchased it from the PO. Check fill caps etc. Easiest, most obvious first. Sometimes just eyeballing the area will reveal a leak. Maybe some dried out seals?


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## film495 (Nov 1, 2013)

Yea, I used it today to move a few inches of slushy snow. It gets clogged up pretty easy, but I know that was likely with wet snow. At some point I'll likely see about painting and waxing the areas where the snow gets clogged up. I put a piece of plywood in the yard to park it on, I don't like the idea of the tires freezing to the ground, but also figure I can track down oily spots or leaks on the board if I've got any drips.


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## Country Boy (Mar 18, 2010)

The transmission reservoir should be filled so that with the tractor idling in neutral, the oil comes up to the top of the threads on the fill elbow in the back of the tractor. It takes something like 5-6 quarts IIRC to fill it. They recommend 5w-30 engine oil for the transmission and you should change it and the filter every 4-500 hours. Your linkage may have been out of adjustment before, but bad oil may have been able to leak by the pump pistons, masking the problem. New oil can make a world of difference in transmission performance. I've had tractors that couldn't climb a 10% grade spin the tires on a 30% grade after an oil change. Many new transmissions claim to have a "lifetime oil" and don't recommend changing it. I've saved several slipping transmissions by changing the oil.

You can get an owner's, parts, and service manual for that tractor by going to www.ariens.com and clicking on the "Support" link at the top. There is a section for you to download the manuals for your tractor or have them printed and shipped to you. Downloading is free, don't know about shipping. The model number should be a six digit number starting with 931. You will need that to download the manual for your tractor.


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## film495 (Nov 1, 2013)

Just a note on the transmission, I ran the machine all winter and didn't look at the transmission level at all. It was warm yesterday and I got the weight box and snowthrower off the machine. Funny, I was as motivated to get it off for spring as I was enthused to get it on for winter. In checking the transmission level, to my surprise it was perfect, right up to the threads at the bottom of the fill hole. I sort of didn't believe it, but the more I stared at it, there it was; perfect.


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## film495 (Nov 1, 2013)

picked up a used deck


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## film495 (Nov 1, 2013)

ran my mower deck for the first time. looked around after and found this below where the pto connects into the gear box. looks like a good bit of the slurry I put into the gear box ran out. do I need to use a thicker grease? or is opening up the gearbox and fixing a seal or something in my future?


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## jhngardner367 (Apr 5, 2011)

Looks like a bad seal. I ran mine,on my Bolens that way,and it destroyed itself!


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## film495 (Nov 1, 2013)

This is the gearbox from the manual. Looks like part 25 is what they're calling an adjustment plug. Any idea how I would adjust that? Possibly there is just too much play and a little turn on that plug might close up that seal, no? Wishful thinking?


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## film495 (Nov 1, 2013)

well, it appears that part 26 is a zerk, so if that's actually there - I'll check my machine later. I think I'll just estimate the amount that comes out, and pump that much back in through the zerk. I also wonder if the other seal or seals are leaking out the bottom. I'd like to avoid blowing up the gearbox.


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## film495 (Nov 1, 2013)

a note on this, I mowed a couple times again. It made a small puddle a little smaller than the one in the picture, and then didn't do it again. Probably a total of about 2 or 3 liquid ounces leaked out. I'm thinking it just squirted the excess out cause I overfilled the gearbox and then stopped. Hopefully, I'm that lucky.


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