Sunstrand hydro... what fluid?

[JimmyJam 542]

Hi! I have a 1968 Electro 12 with a Sunstrand hydro transmission. I acquired the tractor over a year ago, not running. I topped off the the tranny fluid w/ what I thought was ATF. Unknown what PO used (this tractor was so bastardized with repairs/maintenance's.). The hydro had no hoses or lift cylinder; the PO put large hex bolts into the tranny ports. I am going to purchase hoses from Lowell @wheelhorseman. What do I do?? Next? Original manual calls for 10w-30 oil for transmission. The Service Manual was updated in BOLD TYPE to use ATF type "A". Confusing???

 

 

[JimmyJam 542]

I also purchased an another Sundstrand transmission from Joe's Outdoor (He use to be a vendor here) as an alternative, just in case. ++ I have a 1973 "No-Name"  parts tractor with same tranny.

[wheelhorseman 3,211]

Pm sent

[953 nut 55,005]

37 minutes ago, JimmyJam said:

purchased an another Sundstrand transmission from Joe's Outdoor

Joe won't sell anything he hasn't tested so it should be a good one.             

[R. L. Addison 299]

I bought a Sundstrand unit (complete transaxle) from Joe several years ago and put it on a shelf with plans for it a little later (did not work out) and had a problem with the one in my C141, and when I went to install; the unit I got from Joe I drained the oil and did not like the gummy sludge that came out when I drained I it before installation. I split it to clean it out, & the first thing I found was the intake strainer in three pieces. Joe legitimately would not have known that, but when I tore into it and found the pump & motor plates in worse shape than the failed one I pulled from my tractor, (which he said he had tested and was "good operating condition") I immediately decided it had not been PROPERLY tested. It either had not been warmed up at all, or someone who knew nothing about testing one had done the test, or both. I then decided some of the gummy sludge must have been STP, or similar. There was no way that would have pulled its self up a small hill. 

 

All I can say in conclusion is you have to be careful on used units from unknown entities.   Ron

[JimmyJam 542]

Thanks Ron. I did notice that a clearer fluid was leaking out of the Sunstrand that I got @ Joe's. Looked thinner than new motor oil. I didn't smell it to confirm what it might be. What I do know is that the Electro 12 I purchased was used for mowing a very large, hilly lot. PO probably never lifted the deck because he removed the lift cylinder and hoses and plugged the transmission ports with large hex bolts. He also converted the electric clutch to manual type. Which leads me to think he was abusing his machine by cobbling things together just to keep it running. I bought it near dead and not running. I wanted to salvage and revive the poor thing! 

Edited February 26, 2018 by JimmyJam

[R. L. Addison 299]

Not trying to run anyone down, just saying in that particular instance I felt someone dropped the ball on that particular deal. Not that I'm trying to defend him, but the volume of business he does, he has to have help, and we all know the quality of some of the help now-a-days. Ron

[Sarge 3,463]

Most likely at one time the Electro's hoses went south and start leaking or one blew - a lot of hydraulic shops do not stock #4 & #5 ORB fittings to work on the WH cylinders and Sundstrand hyro units , so he blocked them off. The real question you have is to check those ports on that pump block very closely and look for signs of damage to the bottom of the hole as well as the ring area at the surface . There are o-rings that seal these ports on the hoses or factory plugs - if those ports are mangled, forget trying to seal it in the future. Also, there are some very specific valves and springs that control the lift cylinder pressure in that block - if they were not removed it may have damaged the pump already - you won't know for sure until it's fully warmed up and put under a load. Tied off to a tree or whatever, it should easily spin the tires in both directions with no whining or noises - it's common for them to get weak in reverse first and that's a sign of scored/worn parts internally. Some things in that pump can be repaired but for the most part you're better off going to a '73 or later pump unit. The later type is a piston to piston pump that is serviceable and parts are available for it . Everything basically bolts up the same as well with the direction control and such. It is possible that yours has the smaller #4 ports, it will just take a set of hoses with 2 different size ends to address that.

 

The later version pump was used in any older model that had a failed hydrogear - this was part of a dealer bulletin when the pump design was changed some time in late '72 or so...common to see older machines with the newer style pump. I never recommend anyone buying a used hydrogear unless it's free - they really cannot be rebuilt or serviced much, so it's a dead end. Far better off with the more plentiful later model pump anyway.

 

Sarge

[pfrederi 17,635]

Over the years i have accumulated several pumps and motors for D's.  Most all came from "Good Working Tractors".  Upon opening and exam it is wonder the tractor could drive itself to the junk yard.

 

If the PO operated it with the lift hose ports blocked and didn't remove the implement relief valve and move the charge pump relief that would be the equivalent of running the lift to the end of the stoke and continuing to hold the valve open. 

 

It is worth opening it up and looking at the slippers and piston block.  if they are in decent shape then you could go ahead dress them up a bit, check the acceleration valves, clean things up put in new seals and it may work well for you. If the slippers and piston block are badly worm/scarred then you have to assume the gear motor is also been hurt and it is time for a total replacement

[JimmyJam 542]

Thanks @Sarge and @pfrederi!!! This is my first experience with a WH hydro, so what you are telling me sounds like a foreign language to me... I am a hydro Newbie! I just printed up the appropriate Sundstrand Service manual. My Electro 12 is, I believe is a 1968 according to ID tag, but the Kohler K301 tag appears to be a 1969. Transitional year's model or transplant??? The Sundstrand transmission I bought from Joe's Outdoor is the the same Sundstrand but different serial # (obviously), which I have noticed leaking a very clear liquid, thinner than new motor oil (haven't done sniff test) while it is sitting on bench. Hmmm? The good news is that I acquired a 1973 "No Name" Automatic 12 roller. Thinking of swapping that Sundstrand and lift cylinder out. Thoughts? 

[Sarge 3,463]

It would be worthwhile to at least bolt up and test both of those older hydrogear units - they are tougher than most will give them credit for...

The unit from the '73 Auto is the newer model piston to piston pump and should be a direct swap.

 

Sarge

[JimmyJam 542]

On 2/28/2018 at 10:01 AM, Sarge said:

It would be worthwhile to at least bolt up and test both of those older hydrogear units - they are tougher than most will give them credit for...

So @Sarge, I drained ATF from my Electro12 (I saw it had been leaking due the fact the PO must have used Form-a-Gasket on hydro-pump). So I removed the entire hydro-pump. My question is Where do I find a replacement gasket so I can mount the hydro-gear from Joe's Outdoor (to see if it works)?

[Sarge 3,463]

@wheelhorseman

He should have it . If someone used rtv on that hydro that is a real problem  - might want to check out the pickup screen very closely for any debris. No silicone should ever be used around a hydrostatic transmission.

 

Sarge

[JimmyJam 542]

Thanks @Sarge

[pfrederi 17,635]

That you found form-a-gasket in a Hydro it means who ever was in there before didn't have a clue what he was doing. in addition to Sarges advice about the screen i would pull the acceleration valves.  the ports in them are minuscule and easily plugged by stray form-a-gasket bits.

[JimmyJam 542]

Well I took the original hydro gear off. So much junk! Form-a-Gasket bits everywhere. No wonder it leaked and barely creeped forward/reverse!!!

 

 

 

PO was a hack. OOOpps did I say that out loud???  

 

 

Edited March 10, 2018 by JimmyJam

[Sarge 3,463]

I'd hate to see what has gotten sucked into the pump at this point. You're going to be deep into the manual just to clean it out. The good news is there are parts available to fix any damage caused,  just going to take some time and care.

 

Sarge

[pfrederi 17,635]

The good news is that RTV will not do permanent damage to slippers or valve plates...just plugs stuff up

 

What did the suction screen in the transaxle look like?

 

"Put down the RTV and step away from the hydro" should be labeled on every hydro unit.

 

 

 

 

[JimmyJam 542]

Well the Sundstrand #90-2046 that I got from Joe's Outdoor continues to leak clear, thin oil; I did the smell test. No odor at all. Thinking it's mineral oil. I guess after I order the gasket #5955 which is  NLA and replaced by possibly Toro part #102759 from ??? (who, other than Toro)???, I should once again flush the system with ATF. Anyone have any  preferences as to what ATF they use? I will buy by the gallon, because it's cheaper that way to flush. Anyone use Tractor Supply "Traveller" ATF?

Edited March 13, 2018 by JimmyJam

[pfrederi 17,635]

I have used both Wally World and TSC.

[JimmyJam 542]

Thanks @pfrederi!! TSC is just up the road from me and I use the Neighbor's Rewards all the time. I avoid Wally World as much as possible... to the point of boycotting them. I feel they are monopolizing the retail industry. I would rather go out of my way to shop @ a mom & pop hardware store than go to Wally's World. BTW: I have 2 Super Walmarts in my town just a few miles apart. What? NO!!!! Will not go! Just my opinion!