Sundstrand usage chart

[cafoose 3,355]

Is there a usage chart as far as which models had a hydrogear and which models had a piston to piston Sundstrand? Also which Sundstrand models had 1 inch and which had 1 1/8 inch axles?

[daveoman1966 3,758]

Here is the models chart for Sundstrand Hydrogear vs Piston-Piston.  This is derived from an all-inclusive list of Wheelhorse models thru 1985.

HYDRO-GEAR vs PISTON-PISTON MODELS.xlsx

[cafoose 3,355]

@daveoman1966 According to that chart, all GT-14 models have hydrogear. I have six GT-14 tractors, some for parts and others running or to be running some day. Do you suppose someone replaced the hydrogear with a piston to piston in my three with a piston to piston? If so, is it possible to use  the differential case from a piston to piston on a hydrogear unit? My 1-0500 1971 has a cracked case that leaks. I would like to put the gears in the 1971 1-0500 case into the case from the 1-0502 1972 hydrogear case and then put that 1972 1-0502 case onto the 1971 1-0500 piston to piston unit. Here is a list of my tractors with the types of Sundstrands in them:

 

1-7441 hydrogear         1969 parts tractor

1-7451 piston to piston 1970 running

1-7452 hydrogear         1970 parts or fix up later

1-0500 piston to piston 1971 running with FEL and 3 point

1-0500 piston to piston 1971 running, case leaking

1-0502 hydrogear         1972 parts tractor

[daveoman1966 3,758]

The TORO MPV shows all GT-14s have OEM Hydrogear model 90-2062.  If someone has swapped over a piston-piston unit, I've no idea.  go here:  https://lookup3.toro.com/partdex/index.cfm?xCaller=Toro&lang=us_en

Enter model # as :GT-14, then clik SEARCH.   (not model list)

Clik on product details...

Edited March 19, 2023 by daveoman1966

[cafoose 3,355]

7 minutes ago, daveoman1966 said:

The TORO MPV shows all GT-14s have OEM Hydrogear model 90-2062

That's what I came up with in my own research. I guess three of my tractors had them swapped out then So, will a hydro gear differential case work on a piston to piston unit if I put the piston to piston gears inside it?

Edited March 19, 2023 by cafoose

[953 nut 55,739]

The attached post is one of the first posts I ever did on Red Square. The output gear from the hydro gear from a 12" rim   can be removed and replaced by the one from a GT-14. I doubt that the piston to piston output gear would be able to be exchanged to a hydro-gear. Since you have all of those potential donors you could take a look and let us know what you find. When I did the job in the attached post I had been told it couldn't be done, turned out to be a reasonably easy job. Do the piston to piston transaxles have the four bolt mount where the three point lift arms?

 

[cafoose 3,355]

@953 nut  I still need to get the hubs off the 1-0502 1972 hydrogear transaxle. I also need to get the 1-0500 1971 tractor that leaks disassembled before I can look at the output gears. I have no idea what the PO has done to any of them before I got them. According to what I found, they all left the factory with hydrogear units. These are all my piston to piston tractors. First picture is the one that leaks 1-0500 1971. Second picture is 1-7451 1970 currently running no with problems. Third and fourth are 1-0500 1971 with three point and loader.

 

[953 nut 55,739]

First picture the axles appear to be a bit longer, perhaps they are from a "D" Model. All seem to have the correct Transaxle case. This could get very interesting.

[cafoose 3,355]

1 hour ago, 953 nut said:

First picture the axles appear to be a bit longer, perhaps they are from a "D" Model. All seem to have the correct Transaxle case. This could get very interesting.

That seems to give me more evidence that someone was in there before. From what I've seen, most have the hubs closer to the case. Maybe a PO changed the hydrogear to a piston to piston. If so, what else did he use from the donor. If it was from a "D" what other "D" parts were used. The best I can see is to disassemble both and compare parts. The hubs on my hydrogear GT-14 tractors all seem to be about one inch from the case.