Weird Hydro problem

[squonk 41,329]

I've got a C-160 with the piston -piston hydro trans that I got last fall. It plowed snow great all winter. Today I used it to pull a lawn cart around and later

I was towing my spreader. As I was going along with the spreader it felt like all of a sudden it slowed down and seemed like it was struggling. I bumped the lever and it took off again. I thought maybe a tire got caught in a hole or something. It did it again about 10 min later. This time the trans was a little louder and I know it didn't get caught on something. I checked the oil and it was fine. Thew trans felt warm but not hot.

I have no idea how old the trans oil and filter is.The oil is clean but the filter is red and faded as same as the rest of the paint. It's obvious it's been on a long time. The engine oil was very black when I got it and it looks like the rest of the tractor had little maintenance.

I was planning on changing the trans oil and filter but I'm going to do it now instead of later. I see a small allen head plug on the bottom of the trans. Is that the drain? And how much oil does it take? Does anyone feel it may resolve my problem? Thanks Mike

[squonk 41,329]

I forgot to mention, I was running the engine at half throttle when the problem occurred. I finished up at full throttle. I don't know if it makes a difference or not.

[MikesRJ 552]

The transmission service manual calls for changing the oil ad filter as the first step in troubleshooting a tranny which runs in both directions but sluggish when it gets warmed up. It certainly can't hurt at this point. It also goes on to say that the tranny should be serviced every 100 hours or once each year. Sounds like that schedule wasn't followed in the past by the PO.

The plug in the bottom is the drain plug, and it should take approximately 6 quarts. Make sure to clean the tranny area and don't let any foreign materials get into the tranny while changing the fluid and filter.

Manual: http://www.mywheelhorse.com/graphics/file/...n_1965-1982.pdf

[squonk 41,329]

Thanks Mike. Red Square members are the best! :wh:

[squonk 41,329]

I see the manual says 10w30 or 10w40. Would 10/40 be the better choice?

[dgoyette 12]

I would check the plastic cam plate to make sure the guides are not loose or maybe even one side fell off.

[can whlvr 993]

u should run a hyro wide open allways to spin the fan fast enough for the hydro and really the engine too

[MikesRJ 552]

Either would do. It really won't make much difference which one you put in so long as your draining the unit completely, and you are absolutely sure the tranny does not have ATF in it.

[squonk 41,329]

Either would do. It really won't make much difference which one you put in so long as your draining the unit completely, and you are absolutely sure the tranny does not have ATF in it.

The oil in it is Amber

[squonk 41,329]

I would check the plastic cam plate to make sure the guides are not loose or maybe even one side fell off.

THe tractor operated normally after restart but I will check it anyway.

[halbert 0]

The only thing, other than something being broken or loose, that comes to mind for me is the possibility of "cavitation" or low oil level. It seems you've checked the oil level so that leaves cavitation. In this case, if your hydrostatic system is anything like the one in my WH/Sundstrand manual, with a "strainer" in the inlet or "suction" side of the charge pump, I'd see if I could locate where it is and try to clean it. Given the possible lack of maintenance and possibly cleanliness as well, the strainer could be getting clogged up and keeping the charge pump from drawing sufficient oil to keep the closed loop of the hydrostatic charged (full). Cavitation can cause a hydraulic system to do some pretty strange things. If allowed to go on for an extended time, cavitation can cause severe damage to the pumping elements of both the charge pump and/or the closed loop piston pump. Cavitation is almost like having an abrasive blaster at work on the discharge side of a pump.

Henry

[squonk 41,329]

I just changed the oil. I ran it around the yard for about 15 min. to warm the oil then I changed the oil and filter. I ran it around some more and within 5 min it started acting up. The tractor slows, the trans whines and the engine starts to load up like the trans is fighting it. I didn't notice any strainers in the manual but I'll look again :thumbs:

[squonk 41,329]

According to the manual . There appears to be a strainer in the area where the trans motor mounts to the rest of the trans housing.

[can whlvr 993]

yes there is a basket strainer in there,be careful because i dont beleive its available any more,it sounds worse than that though :thumbs:

[squonk 41,329]

I found a service bulletin for " sudden loss of power" #195 . I points to a snap ring failure on the hydro motor shaft. Parts are NLA. I may be able to get a trans out of a C165 with out a lift. Will it fit and can my lift valves be put in?

[squonk 41,329]

Talked to an old time mower guy today and he told me to change the oil again and use Mobil 1. I figured why not what can it hurt. I ran the tractor about 1/2 hour around the yard with no problems today. I don't know if it's fixed yet but I figure if there was something really broken in the hydro it should have still acted up. I will keep you posted.

[can whlvr 993]

hopfully you are good to go

[squonk 41,329]

Nope. Acted up again tonight. Off to the shop it goes. :thumbs:

[squonk 41,329]

While waiting for the guy who is going to work on it to get back from an Easter trip I've done some reading and checking on other things. The service manual seemed to point to the hydro motor so I got one if needed. I ran it a few min. the other night and I felt like something was binding rather than a loss of hydro pressure. I went to move it this morning to get my other mower out and discovered that the tractor cannot be pushed with the tow valve open. It will roll about 6 " then stop. The valve only opens an oil passage so I'm thinking it is indeed the hydro motor or something in the differential.