Power steering conversion on my kubota B8200

[fatjay]

I finished my cab & snowblower on my b8200, pulled it out of the garage the night before our one and only snow storm, turned the wheels and snapped the steering column. It was tough to steer before, but with the blower up, the added weight was to much I guess.

I mended it, but not much of a long term solution. Steering was loose before as it was, I would have to end up replacing the entire thing with a new one, then still have hard steering. And that will cost me $600+. There's no universal kits anymore for this or anything similar that I could find. Basically not a lot of options.

I picked up a power steering valve from a john deere 318/322/324 or a few others. Basically it's the entire steering column plus valve outlets on the bottom in one piece. Quite convenient and compact, so it should be easy to adapt. I also picked up a 15" hydraulic cylinder to control the wheels. The thought is to come off the hydraulic block supplied on the tractor, into the steering column, and out to the cylinder, to move the wheels left and right. Couldn't be easier, right?

Taking off the old power steering was a challenge, gas tank needed to come off. When I put it back in place, I had a lot less room to work with than I originally thought. Also, to give myself the clearance I needed for the hydraulic lines, I'd have to have it much higher than it was on the old one. I'll worry about that when it works, for now it's getting it mounted. I'm going to get some 90 degree fittings for the valve so I know how much space I have to work with and have it still clear.

The other option is the block fits right into the hole, get the lower mount, so the ports are inside. I don't like that option as it puts the lines next to the driveshaft, but on the other hand I'd be able to use the original mount bolts and it would already be lowered to a more comfortable position.

I grabbed a piece of scrap angle iron and cleaned it up to cut for some test fitments. I'll post info as I go.

 

[2458n]

Water runs right down the steering column. Sits in the bottom and freezes. I armstronged mine and broke the spiral with the ball bearings. No one to blame butt myself. Parts were still available then. Fixed it back up and put silicon under the plastic steering wheel cap covering nut and shaft. Wrapped the top of the column very tightly with electrical tape,reversing the first layer so column would not be trapped. 25 yrs later living outdoors in Ohio the power steering is still working. L245DT.

 

[fatjay]

That's what I thought happened but when I took it apart, the whole thing was filled with oil properly. I broke the part at the top of the spiral that the pin goes through, which tells me it just couldn't handle the force. When turning it was being pulled apart by the gear pulling down as the spiral spins. Moving the tractor without steering was a challenge.

 

[TMGT]

I have a b7200 with an aftermarket ps system similar to what your doing, you'll want a priority valve also.

 

[fatjay]

What's a priority valve?

Got my cylinder in as well as the angles for the steering valve. While the wife wasn't looking I put them on the dining room table and got them set up. Going to make the mounts hopefully this weekend, time permitting. 4 right angles and a cap for the AUX port. I'm not convinced you can cap the AUX, but I read several places that you could so I'm going to see what happens.

 

[CADplans]

I'm not convinced you can cap the AUX, but I read several places that you could so I'm going to see what happens.

I think the AUX is like power beyond.
If you are powering the power steering with a charge pump (ie,, a garden tractor) the pressure is low,,
Possibly that application will allow capping.
A kubota could destroy a hydraulic pump,, if you cap a power beyond port.

 

[TMGT]

What's a priority valve?

Got my cylinder in as well as the angles for the steering valve. While the wife wasn't looking I put them on the dining room table and got them set up. Going to make the mounts hopefully this weekend, time permitting. 4 right angles and a cap for the AUX port. I'm not convinced you can cap the AUX, but I read several places that you could so I'm going to see what happens.

Priority flow valve, on a single pump system it makes sure the ps system has adaquate flow, any access is used for the downstream hydraulics. Otherwise you can lose steering if you operate another valve at the same time.

 

[fatjay]

I'm pretty sure that's built into the hydraulic block. The block has dedicated ports only for power steering, and other ports for other hydraulics. This will be the only thing on this hydraulic line. The only other hydraulics I even use is the 3pt lift on the back for the mower.

The only thing that really concerns me is the deere 318 this is from is very light in comparrison to the kubota, at 1900lbs. I broke my steering column trying to turn the wheels with the blower up, so I'm hoping this can handle the pressure.

 

[TMGT]

Did your 8200 have PS originally?

 

[fatjay]

It did not, but they all come with the ports for it, just capped off. These two on top here are for the PS, the two bigger ones on the side are for heavier devices like the FEL. I'm basing this off looking at my father's B7200, which has the same block, has factory power steering, and a factory loader.

 

[TMGT]

Then you're good to go, my B7200 doesn't have that valve so it has an aftermarket priority valve off the pump.
Might have come on the loader equipped tractors or if it had factory PS?

 

[fatjay]

That's possible, his blocked looked a lot like mine.

So I got the cylinder on. Drilled out the wheels side to 1/2" and used a hardened bolt with nylon nut. Used the factory rear hole with a M10 1.25 pitch 8.8 bolt. I may try and find a 12.9 but I'm not sure I will actually need it. Everything is snug, feels like it was made for it. The cylinder's ends being rounded eliminates the need for tie rod ends, I'm not sure how much wear it will endure though. No way to grease or lube it other than slathering it on.

 

[TMGT]

My Simplicity Sunstar uses the same ends on the PS cylinder and doesn't have any notable wear at 1k hrs, although it doesn't have as much load on it either.

 

[fatjay]

Got a rough cut of the mount for the steering column done.

 

[fatjay]

Had the hoses made today. Only thing they didn't have was an adapter from the hydraulic block on the kubota to the 37* JIC, so I'm waiting for that to come in. Nothing's tightened down yet as I'm still testing fitment.

Parts were 3x12" ½" hoses, 1x18" ½" hose, 1x26" ½" hose, 1 ½" T, 2 elbows on the hydraulic cylinder, 5 elbows on the steering cylinder, and waiting on the adapter from banjo to ½".

 

[kebo]

That rounded piece of sheet metal that the tank sits on makes a great paper towel holder, it looks like it was made for it! :laughing: Seriously, that's some good "engineering on the fly" you're doing there. I hope when you fire it up and start using it, it works great. I'm sure it will be major improvement driving and steering it.

 

[CCWKen]

Yeah, looks good! I thought this was going to turn into a 10-cent carnival ride but it's turning out to look great. :thumbsup:

 

[Egon]

Very nice job. Good workmanship.

Years ago I was thinking about putting power steering on my B7100. The local Kubota mechanic talked me out of it as the pump flow rate was not really high enough. Seems they had tried it a few times.

Just for interest I was going to use a 70's GM. Recirculating ball steering box. It would have been a very simple mount. Just placing it where the original box went and putting the steering shaft on top of it. The pitman arm?? Would have been an easy fit.

 

[fatjay]

Finally picking up the last parts today. Two adapters that go from JIC into the banjo on the power steering supply block.

The only complication I'm anticipating is the length of the steering shaft. It's about 2" longer as it sits, preventing me from getting the dash up and over. I think I'm going to cut it down, but also cut the steering wheel mount off the old system and weld it on, so I can use the kubota steering wheel. Assuming all goes well, I should be up and running tonight.

 

[kebo]

Finally picking up the last parts today. Two adapters that go from JIC into the banjo on the power steering supply block.

The only complication I'm anticipating is the length of the steering shaft. It's about 2" longer as it sits, preventing me from getting the dash up and over. I think I'm going to cut it down, but also cut the steering wheel mount off the old system and weld it on, so I can use the kubota steering wheel. Assuming all goes well, I should be up and running tonight.

That will make for some extra work now, but I think it will be worth it in the end as it will help make the reassembly (fit/finish) easier and better looking. Good luck.