Hydro Transmission Questions
 

I was told that there is a difference between the transmissions for a 982 and a 782. What is the difference here? Is it a different hydraulic motor? The only differences I saw were the hydraulic motor and the brake assemblies. If the only difference is the hydraulic motor, what makes them different? Are they interchangeable?

Thanks in advance,

Nate

YES....there is a difference. It is in the output shafts. See attachment....

The output shaft of the hydro pump is different, but that's not what Roland posted a picture of. The hydro output shaft has one less tooth on a 982, and consequently the driven reduction gear is larger. You cannot interchange the pumps on a rearend without changing the driven reduction gear to whichever one belongs with the pump you are using. Also, the 982 pump has a splined input shaft.

Roland's picture is of two pinion shafts, with the one on the left being from a cast iron rearend, and the one on the right from an aluminum rearend, which could be either out of a 982 or 782 or something else...it doesn't matter, because the pinion shaft is not different between a 782 and 982, provided both have either a CI rear or both have an aluminum rear.

So would the reduction gear from an aluminum rear fit on the pinion shaft from a CI rear? The fact that the input splines on the pinion shaft are the same and that the pinion shafts are the same part number leads me to believe they are the same. Is this correct?

There were three (3) basic Hydro units that IH bought from Sundstrand

* 717-3032 Non Ported
* 717-3033 Ported
* 717-3034 High Capacity SGT

There is a difference between the 717-3034 (SGT) and the 717-3033. IIRC correctly, it is two fold. Different output shafts and they label 717-3034 as "high capacity".


Matt:

How do you explain, that for example, the 782, that the Hydro Unit for the Cast Iron Rear and Aluminum Rear is the SAME (717-3033) per the Parts Manual.

What about a 1450/1650 rear? The parts comparisons look like the only differences are:
- Reduction gear would have to be changed to the 68-tooth
- Hydro pump from the super (3034) would have to be used instead of standard (3033)
It looks like the bevel pinion shaft input splines are all the same. Looks like any reduction gear will fit on any bevel pinon shaft - is this correct?

The hydro units are the same in all of them except. First it being ported or not, and even the ported "plugged" ones can be converted to a full ported pump.

And that the "super " pumps have a spline input shaft, and a different tooth count on the output shaft. The output shaft of the super will only mesh with the reduction gear from a super and the same goes for the "regular" non super pumps. The reduction gear has a splined hole in it that will fit any pinion shaft. The only difference in pinion shafts is whether they are straight cut or angle cut. This also will play a part in what ring gear, carrier , and axles you use.

But if I don't change any ring gears or axles, I should just be able to switch the reduction gear, use a super pump, and everything will work out fine, right?

Nate

Yes, what exactly are you trying to accomplish ?

I am trying to find a cast iron rear for my super and am wanting to know if a few modifications to a standard cast iron rear from a 1450, 1650, 782 would suffice if I switch the reduction gear and hydro drive motor.

Thoughts or comments? Most importantly, will it work?

Nate

maddog784-

Visit my website in my signature line and go to the 'tractors' page and then the '1872' page, as I have replaced the aluminum rear in my 1872 with a CI one, and documented the process there.



Huh? What does that have to do with either the picture you posted initially, or the question the OP asked? You aren't making any sense at all...

Thanks for the walkthrough, Matt. It doesn't seem like I have any questions, but I don't intend on changing out the rear diff carrier and other hardware. Thanks again guys, you have given me confidence. This may not be a good thing:bigthink:

You might as well swap it out too, as it's all got to come out so you can swap reduction gears.

Mad Dog

I just did one in my 1872 and followed Matts guidelines. It took me about 3.5 hrs for the first time. Youll want to get a new welch plug for the front, AND DONT RUIN the clup on the front, its NLA and as of now I cant find another one.

Vince,
which clip?
One that holds that shaft under that plug?

It seems that's the one that you shouldn't ruin - as someone who tinkered with that freakin' plug today, I can understand accidentally (or purposefully) breaking that PITA. The new gear is in - no issues. Next I need to prep for painting and get it sealed back up.

I am not one to take advice well, but seeing how MattG has never given bad advice, I decided to take the inners from the aluminum and put them in the CI rear. Great advice, Matt.