Steering Box adjustments questions '78 Kubota B7100D

lake rat · Aug 11, 2009

Hi,

Just bought it 2 months ago...1100 hours. Steering went out last weekend. Pulled the upper steering box and shaft. Upper roller bearing on steering shaft disintegrated. Bearings in the lower box and worm gear. Some visible wear on steering shaft worm gear but the knuckle & down line gears look good.

local dealer quotes $359 for new steering shaft - not in stock. Elected to replace upper and lower roller bearings, upper oil seal and top steering shaft bushing. Put 'er back together and still no steering. Totally free play.

Can I make adjustments to the steering box. Lots of adjustment screws exist on the right side off the box if you're sitting in the drivers seat.

What do they do? What can I try before giving in to the dealers $500+ repair agenda?

Thanks in advance...

Egon · Aug 11, 2009

Trying to recall what I did when I replaced the steering boxes on mine but the memory is kinda dim.

Is the shaft sector in with the gears able to make contact with the worm gear. Does the worm gear have all the ball bearings in it?

My first gear box went out at about 1100 hours also. The second at about 2000 hours and the third at 3000 hours.

lake rat · Aug 11, 2009

Egon said:
Trying to recall what I did when I replaced the steering boxes on mine but the memory is kinda dim.
Is the shaft sector in with the gears able to make contact with the worm gear. Does the worm gear have all the ball bearings in it?

My first gear box went out at about 1100 hours also. The second at about 2000 hours and the third at 3000 hours.

Egon- Doesn't seem like the shaft sector/worm gear on steering shaft are contacting much at all. The worm gear DOES have all bearings. I fished our ALL the bearings which had fallen out of the top thrust bearing. bottom thrsut bearing was in tact. I replaced both sets of thrust bearings (upper at top of the gear box) and lower-which the bottom of the steering shaft, bottom of the worm gear, sits on.

Attached is a schematic/parts list to assist the discussion:

lake rat · Aug 11, 2009

Also, what I called the "knuckle" in my original post is listed as part #3 "Assy nut ball" on the diagram attached to my last posting. I did manually move the tires full range back and forth, left and right, to ensure the knuckle/assy nut ball was full seated on the bottom thrust bearing (aka diagram part #4, "bearing thrust ball." Is that the correct position for the assy nut ball?

Greased the **** out of both thrust bearings, but have not yet refilled the gear case. Thinkin' it's not fixed yet and with help from some of you on TBN I might be back in it to try again in the near term.

Again - I appreciate your feedback and need all the help I can get.

Egon · Aug 12, 2009

Afraid my memory has failed but I may have centered the "Assembly nut ball" on threaded portion of the shaft going up to the steering wheel. Then placed it in the case and then slid the "Shaft Sector" in place with the gears at midpoint and tightened the "Adjusting Screw" so that proper contact was made. When the gear case was bolted down I'd have found center for the steering wheel and then put the "Pitman Arm" in place.

Hope this is of help as I'm not sure if it is the proper procedure to follow.

lake rat · Aug 12, 2009

Egon - I will retry with the centered assembly nut ball and pitman arm instructions you just offerred. Also found these sites (1) with steering gearbox rebuild instructions which may be useful & (2) general kubota :

1. Contact us

2. Kubotabooks.com

THANKS a BUNCH.