Kubota B7100 Steering box

[Pacific Pete]

Kubota B7100 1100 hours.

Hi Guys have had this tractor for 20 years now. Bought it used at 300 hours, and it has been well maintained,and serviced all its life.

Pushing snow the other day the steering became stiff, and a cracking sound came out of the steering box. I had just changed the oil ,and winterized the tractor. So we ripped it apart and found the upper trust bearing in the steering box had let go, allowing the ball bearings to migrate into the areas below.

After getting all the parts out I find the steering shaft ,that the steering wheel, attaches to has also been damaged. Went to the dealer for parts and I find this shaft is no longer available as a spare part.

Anybody out there that can suggest a place to look for this part, or a substiute used part, would be greatly appreciated.

Tractor still runs well and is ued around here daily for snow removal, rototilling and cutting grass.

Thanks in advance Pacific pete

[Egon]

Try an auto wrecker and see if you can find a manual steering box that will fit in the old ones place. Might take some revising but may work. Some of the GM circulating ball power steering boxes would fit with no problem.

[charlz]

There's been more than a few threads on b7100 steering. When mine went out the only way I got one was out of some dealers in Texas back room. Must have been the last one.

One option is to go to power steering, couple threads on that.

This site:

Kubota Tractor Parts: Steering Parts || Weaver's Compact Tractor Parts & Compact Tractor Salvage

shows some steering parts for other tractors, maybe you will get lucky and can get one that's close in length or whatever and have it modified to fit. If you go that route please post the info.

[Soundguy]

What's damaged about the steering wormshaft? The area where the bearing rides? I'd sleave it.. or weld it up and then turn it true.

I've got a ford 8n that's had it's steering wormshaft fixed that way... 20$ vs 250$

soundguy

[Kernopelli]

Give these folks a call, if you scroll down the page you will see they carry some old Kubota steering parts.

Little Miami Trading Company - Tractor Parts Books

[myyaz33]

Don't have the Kubota B6100 anymore, but I bought the whole replacement assembly from the link below for $135(bottom of page). It should also fit the B7100, I think..

No way would I spend $400 that the Little Miami Trading Company wants for one. (Call me frugal!)

Kubota

[charlz]

What's damaged about the steering wormshaft? The area where the bearing rides? I'd sleave it.. or weld it up and then turn it true.

I've got a ford 8n that's had it's steering wormshaft fixed that way... 20$ vs 250$

soundguy

I kept my old one, will have to look at it again. I think the key problem was that when the upper thrust bearing dissolved it toasted the 'ball nut' and bearings/races... which is what damaged the shaft (bad nicks). The site I posted sells a nut and bearing/race kit by themselves. Have to measure and see if that is a workable replacement or not for the b7100. Likely the nut doesn't really get damaged and a guy could get away with new/repaired worm shaft and bearings/races.

[Soundguy]

Bearing race? Big deal.. snatch or weld it out and replace.. that's why cups are replaceable..

Ballnut.. permanently damaged by the upper thrust bearing disintegrated.. ok.. but I've never seen that on any steering box I've ever rebuilt that used a recirculating ballnut.. and every one of them had a thrust bearing in some state of damage from near good to nonexistant.

nicks on the shaft? where? 95% of the shaft is not a contact surface so nicks don't count. nicks on a bearing surface can be fixed by sleave or build/cut.

post back some details.. unless you are just dead set on $$$BUYING$$$ a replacement, vs FIX$ING your current one.

soundguy

[Pacific Pete]

Thanks for all the replies,and suggestions.

I took the steering shaft to a machine shop today. They are going to rebuild the bearing surface on the shaft, by welding, and then turning it down to fit the new bearing. Cost estimate is $100.00.

I bought new bearings and seals at a bearing supply store, so will be set to go, once I put it together.

Kubota dealers around here ,were helpful, but only on new parts. There is a substitute,steering shaft that is still available, but it is 3/4 longer, which is no big deal. Cost 255.00 from Kubota.

Had this tractor for over 25 years now, so it is time to look for a newer version of Kubota.

Thanks for your help and relplies, they were a big help. Happy New Year to all Pacific pete

[charlz]

Bearing race? Big deal.. snatch or weld it out and replace.. that's why cups are replaceable..

I meant the 'races' (tubes) for the recirculating bearings.

Ballnut.. permanently damaged by the upper thrust bearing disintegrated.. ok.. but I've never seen that on any steering box I've ever rebuilt that used a recirculating ballnut.. and every one of them had a thrust bearing in some state of damage from near good to nonexistant.

My old ballnut does appear to have some superficial nicks in it. I think the key problem is between the nicks on the shaft and the damage to the tubes bearings were allowed to slip out. If you assemble my old one and run it back and forth a bit bearings start falling out of it.

nicks on the shaft? where? 95% of the shaft is not a contact surface so nicks don't count. nicks on a bearing surface can be fixed by sleave or build/cut.

What do you mean by 'sleeve'?

post back some details.. unless you are just dead set on $$$BUYING$$$ a replacement, vs FIX$ING your current one.

Well, I am not the OP... my tractor works I am just curious because I think I bought the last new b7100 ball nut assembly in existence. I also recently acquired a small lathe so I am curious now if I can fix my old one.