Sundstrand transaxle question- AGAIN...

[kpinnc 11,877]

First off, thanks for all the help with my previous post about looking for a manual for the auto trannies. As many times as I have been to the Toro site, I hadn't figured out a "back door" to getting a manual for just the tranny by searching for a DIFFERENT model tractor than my Bronco.

Of course, this question may make me look like an even bigger doofus, but I can handle that...

I've really dug deep into the manual, and it's very detailed. One of the points made in the service section is to look closely at the strainer and magnet at the intake for the charge pump if you remove the hydrogear assembly. It says that if there is "alot" of metal on the magnet and strainer it is an indication of the overall condition of the pump internals. Sounds like common sense, right? OK, WHAT IS "ALOT"? The manual says to clean the strainer and magnet before re-assembling, so that tells me SOME residual metal "GOO" is acceptable. I truthfully expected something similar to what you find in a car tranny on the magnet in the tranny sump on a fluid change, and for the most part, that's what I found. There were a few little slivers (comparible to say, and this is the closest thing I can think of, razor stubble in the bathroom sink when you shave) of metal on the magnet, but it appeared to be just a few. Of course there was trash and a few flakes/slivers on the OUTSIDE of the strainer, but that didn't really concern me. And, it looks like the filter on this tranny is the one that came with it new. It's a 1971 model...

I know a few of you have been inside one of these, but it's my first Sundstrand, so I'm reaching a bit. Also, keep in mind I have no idea as to the condition of the tranny. I dropped some trash in the thing by accident the first day I got it and didn't run it for fear I would mess it up.

To summarize this long, drawn out question, I need to know if anyone can give me an idea about how much metal they found during teardown of the tranny. I have no idea what "alot" means in the manual. I don't want to tear into the hydrogear if I don't have to, and I'm trying to make a guess without much prior experience. Has anyone else noticed any metal in the strainer, or am I just over-reacting to what is normal wear?

If anyone can help, I'd sure appreciate it. I'm trying to make the decison on whether it would be worth tearing the thing down further. My origional plan was to just flush it out and put it to work.

Thanks!

[kj4kicks 151]

ok, opinions are like... well, you know... But here's mine: from what you describe, flush it out, put new oil in it and a new filter on it, and run it. Mine chewed up a snap ring and retainer, so I did see "alot" af big pieces. Otherwise, just some small slivers and goo, like you described.

Here's a hint, use a dab of grease to hold that strainer in place while you assemble everything. If it jumps out of it's groove, the gasket won't seal.

If you have access to a high pressure gauge, run a test when you get it back together. The manual has the specs and port location.

Even if you have to tear it down again, the gaskets should be re-usable, since they haven't been heat cycled.

The hydro isn't too tough to overhaul, except for that slipper valve assembly in the motor section. They are tough to get apart, unless the retainer fails and it blows apart (like mine did). That being said, if the pressure test is good, don't spend the time rebuilding it. About the only parts you can get are the o-rings and gaskets.

Eldon.... driving the C160 like I stole it !!

[kpinnc 11,877]

Thanks Eldon, I was hoping you'd be one to reply to this. From what I've heard today as well from a couple other folks, I'm gonna do just that.

When I think about it, a few tiny slivers and some goo isn't bad for a 36 year old tractor. I'm not sure about the filter, but I'm certain I'm the first to have opened it up.

Do you run 10W-30 in yours? Mine has Dextron II in it, but I've read that motor oil is what to use now.

Thanks again!

[kj4kicks 151]

The old 1077 uses ATF. The newer C160 and 520H use 10w30. Check the manual for what your's is supposed to have. They changed over around 1973 or so (I think).

When I rebuilt mine, it had an old red Wheel Horse filter. May have been original, maybe just been awhile since it was changed. I was happy to see that the parts inside showed very little wear, even after eating a snap ring and frying a retainer clip.

Enjoy the ride.....

Eldon.

[kpinnc 11,877]

Yeah, I split the case on the transaxle last night. I've opened 4 or 5 trannies now, and this was by far the cleanest, and all the bearings were smooth and tight. All the surfaces were polished, but with no visible wear at all. Had it not been for the fact that I'm swapping differentials (from 10 pinion to 8), I would've regretted going into it.

As far as the oil, you're right per the manual. but it does say many older ones have been converted to 10W30. Problem is, you have to flush ALL of the ATF out of it. There's a warning about it, but it dosen't explain why. Given the fact I have hydraulics, and how well it has worked with ATF, I'm gonna stick with it.

Thanks Eldon!

Kevin

[kj4kicks 151]

Hi Kevin, no problem at all.

Basically, ATF is equivalent to straight 10 weight oil, but of course with more additives. Personally, I would not change from what it calls for, but I guess some people do. Machined clearances are designed around what weight lubricant is specified. That's why car dealers add gear lube to a noisy engine, it takes up the extra clearance (wear).

The viscosity of 10w30 is 30 when it's warm, so it is actaully "thicker" than ATF.

When it comes to oil, stick with what the manufacturer recommends.

Congrats on the upgrade.

Eldon.... with all the right fluids.....