Mini Motor Grader build

[Sam Mac]

Originally Posted by sawdustdad

No. Not planning to use one. Just commenting that they were belt driven. In response to Sam Mac's comment that a Cub hydro input shaft can't take side loads such as from a pulley mounted to the shaft. I was noting that the Sunstrand on other tractors is belt driven.

I looked at the charge pump, it has a roller bearing in it. I think it will be fine with a pulley on the input shaft.

Your call.

[ol'George]

https://www.machinedesign.com/learni...tween-bearings

[sawdustdad]

Originally Posted by ol'George

https://www.machinedesign.com/learni...tween-bearings

Charge pump has roller bearings, or, maybe due to size are classified as needle bearings, both good for radial loads. they look similar to those used in the axle housings.

[sawdustdad]

Some progress. Focus now is on getting the engine configured to run, extending choke and throttle cables, basic wiring, etc. In process of fabricating the front panel to hold the forward end of the hood, which will include a solid panel to stop hot air flow toward operator. Once engine is in running shape, I'll put the four rear wheels on and go for a test ride.

[twoton]

Good to see your progress and that you've recovered from your injuries.

[sawdustdad]

Originally Posted by twoton

Good to see your progress and that you've recovered from your injuries.

Thank you. I'm about 95%. Still some range of motion limitations behind my back from the rotator cuff surgery. But mostly doing everything as before.

Update on the grader build. I've spent the past week mounting the fuel tank, carb, starter, etc, then extending the wiring harness, choke and throttle cables to the rear. Everything's hooked up and works from the existing dash.

Turns out the starter is not strong enough to start the engine with the two hydros attached. Not sure why because I did not have this issue with the Tandem I built two years ago. And the tandem also had a hydraulic pump in line as well. It starts easily, even when cold.

I tried a different starter, no improvement. I disconnected the drive belt and the engine started instantly and ran great. It's a new overhaul, so first start is always very satisfying. I hooked up the drive belt and using two batteries in parallel got the engine started, and it ran fine. But subsequent start attempts did not go well. Just too much drag on the starter.

I have to adjust the tie rod between these two hydros as they are clearly not sync'd. With the axles in the air on jack stands, it's easy to tell. I don't think that is causing excess drag as each axle is free to spin independently.

My plan now is to install the PTO clutch throw-out arm and use that to disengage the PTO to make starting easier.

I'm looking at a hydraulic pump/motor set up but that complicates things a bunch but also solves some issues. Will keep working with the belt drive for the time being and see how it goes but I don't have high confidence in it.

[ironman]

sawdustdad, just musing about your starting woes, you never mentioned the operational status of the donor tractors.....
could it be that one of the hydro pumps has an internal issue and is providing more drag than it should?
Maybe if you remove the spirol pin from the coupler on the front hydro so the driveshaft is free to spin,
try starter again and see if it turns any easier with just one hydro to spin.