Grader Build Planning
 

I am starting a grader build and will preferably keep the engine in the proper orientation under the hood which means it will be spinning opposite of the standard rotation. I am considering some sort of parallel gearbox or belt setup. I don't have an super tight budget mainly I want to do it right. Does anyone have any war stories to share in regards to this? Thank you.

:American Flag 1:

A few years back another built a grader. Here is the link.

https://www.onlycubcadets.net/forum/...ad.php?t=56461

He has it all on YouTube, here's link....
https://www.youtube.com/watch?v=Gl26X0A6YcA

Thanks for the help, I have seen both of those. Unfortunately they both have the motor spun 180deg in the engine bay. I am using a 1250 which has side panels and the exhaust comes out the front (which will be the new rear), I have considered rotating the engine in the bay and running a new exhaust pipe to the back but the problem is the hot air from the engine fan will need to go down past the hydros in that configuration because of the side panels. This is one of those projects where appearance is as important as function so I guess I need to put my engineering hat on. Thanks again for the help!

:American Flag 1:

Hydro Ops
 

So I am running into a slight issue with my design. Because I am using a 1250 for the engine bay it is almost impossible to rotate the engine in the bay to have the correct rotation for the hydros that will be sitting underneath the engine. I ran the hydro in reverse operation with a drill to check if it would work and it did. Of course reverse is now fast and forward is now slow, is it as simple as taking the swashplate out and flipping it to make forward the faster speed? Does anyone have any experience running the input in reverse rotation? I know the pickup now is in a different location and oil starvation could be an issue, are there any other concerns?

FWIW:
If you didn't know, those old Sundstrand Hydro's were used in a boat load of Mobile vehicles, way to many to list.
That said, some needed the input shaft rotation changed because of driving off engines that used the PTO end of the crankshaft unlike Cub that used the Flywheel end of the crankshaft.
To change the input rotation, just turn the charge pump 1/2 turn and bolt it back on.
Yes it is as easy as that.
If one tries to drive the input shaft reverse of what cub's rotation is, it will not
operate, unless the charge pump if flipped or turned.
in other words,
the notch on the one ear of the charge pump mounting bolt flange, needs to be on the other side.
Clear as mud? :bigthink:

Now that said,
it is not advisable to run cub differentials reverse of what they were built for,
as the ring and pinion, being driven in reverse direction, tends to stress the snap ring on the differential pinion shaft small end,
as the pinion is now being pulled into the ring gear instead of being pushed away with the thrust no longer being on the tapered pinion bearing.
Best to use the hydro's and differentials as designed as far as rotation, unless you are only using the hydro's and some other differential setup.
Hope I've not confused you more. :bigeyes:

Adding to what ol'George said,
here's a link to the "flip ring" question on another forum.
Maybe it'll help ya or just make it more muddy....
https://www.redpowermagazine.com/for...ing-ring-gear/

Thank you both! I had a 125 as a kid used it to mow then entered it in our town's inaugural garden tractor pull in 1990 and won. I was impressed then as to how over-built the tractors are and now even more impressed with the strength and versatility of the parts. All I need is to reverse the input rotation to accommodate the engine being rotated 180 deg, the drivetrain will all be rotating in the same direction as stock. I have been scratching my head for a week trying to find some sort of 1:1 reversing gearbox or running a pully on the backside of a belt to make it all work, I should have known they had some insanely simple solution!!!! Thanks again!!!!!!!

:beerchug:

So I went out into the shop. Took the two bolts out of the charge pump, rotated it 180 deg and it still runs in the same direction. CCW input, push back on the hydro lever, wheels drive forward. I think I am clear on the charge pump, it is the forward input shaft with two bolts, one ear has a flat side the other has a rounded side. Just remove the two bolts, spin the cover 180 and rebolt?

If you change the input rotation, then you have to change the pump lens plate. That's the round flat bronze on one side plate that the barrel face rides on. They are rotation specific. CW or CCW. It will work at very low rpm but at operating rpm it will be noisy then self destruct.

Why do you want to run it backwards?

Thanks for the info, I am trying to build a grader. Because I am putting the engine over the axles with the front becoming the back the rotation is opposite from original.

Is there something you don't like about the way Sawdustdad (in Delta's link above) moved his engine back and ran off the front pulley. Pretty efficient and straight forward.

On Sawdustdad's build, the engine has the original orientation, it's moved back and over the axle with the "front' pully over the hydro input. The grill support and hood are backwards. If your doing all that fabbing anyway it should be fairly easy to maintain the hood orientation as well. Not sure how you'll close in the back to make it look "factory".

Maybe post some sketches or mock ups so people get a better idea of what you're aiming for.

Because I'm using a 1250 for the hood and side panels the engine will need to stay oriented with the hood to keep the exhaust and cooling air going out the grill. I considered changing the orientation in the engine bay but things like the air cleaner have their own bump in the sheet metal side panels which makes it a lot harder to spin the engine in the bay.

I guess I'm just missing something in what you're trying to accomplish.

I have attached a sketch of the issue. The most basic way to explain it is the engine from the factory had the flywheel and the hydro facing each other which means the input to the hydro spins CCW. I am trying to put the engine over the hydro with the flywheel and the hydro facing the same direction which will turn the input the opposite direction. I cannot turn the engine to use the PTO end of the engine because the sheet metal doesn't work with the side panels.Attachment 115664

I know you guys are pretty far along in the grader topic on this thread.... but I want to backtrack and ask you (Ambush) this for my own edification: You advised the OP against changing the rotation because the lens plate are rotation specific unless some changes were made. I was also wondering about the charge pump? Isn't that rotation specific?

Is this something that can be flipped or do I need a different part. I had the charge pump opened up and that is as far as I got into it. I assume the lens plate is deeper in?

You can change the rotation of the charge pump just by rotating the housing 180 degrees. You have to change the hydro pump lens plate for one of the opposite rotation. Rotation is always determined by looking at the input shaft. CW is right hand rotation, CCW is left hand.

You have to partially disassemble the hydro to change the lens plate, if you can find one.

Got it, thank you for the info. To put this one to rest and be sure I am understanding you correctly, If I rotate the charge pump housing 180deg, and find a CW lens plate and run the input shaft CW the drive and axle will operate as it did originally? I am just trying to keep my drivetrain as simple as I can.

You need something like this, kinda pricey though....
https://www.colemanracing.com/Steeri...Drive-Gear-Box

I should clarify and probably add some confusion at the same time :bigeyes:

When I said " pump rotation is from looking at the input end" I should have said for standard applications. In the case of these hydros, the shaft protruding from the "back" is actually the input for normal pumps.

So even though your "input" turns CCW (left hand) the lens plate inside is CW (right hand). If you want to change direction, you will need a CCW plate.

There are several videos online that will give you a very good idea of what is involved in a teardown and hardware inside, but each one contains a few things that are definitely not the correct procedure. But still very helpful from an understanding point of view.

Just google sundstrand U15 repair video


You could consider turning your engine and driving to the rear pump shaft. Looking AT the flywheel, it is turning CW. Placing the engine with the flywheel to the rear over the rear shaft of the hydro should give you the correct pump rotation.

It's early morning here and I'm only done half of my first coffee, so verify that.

The price of that doesn't scare me away and conceptually that is what I need the only problem with that specific one is it would never handle continuous power, it is just made to reverse a steering shaft.

I appreciate the info. I would simply rotate the engine if it would work with the sheet metal. I am using a 1250 with side panels and wanted to keep it all intact for asthetics, cool is expensive...:Thanks:

Looking forward to seeing your build progress. Keep us updated.

Always interesting to watch innovation. Good luck!