I have an 8n with the early steering box. The steering started to lock up and stick so I opened up the gear box and the upper thrust bearing was destroyed. I started the rebuild by replacing the Welsch plug in the bottom and put new lower and upper races and bearings in. I followed the shop manual on the install but when trying to adjust the preload and sector arm backlash I keep destroying the new bearings. I need to order a third set. when making the adjustments I have the front wheels off the ground so there is no load. Any advice??
I put the welsh plug in with the curve down (when looking down from the top of the box the plug looks like a bowl). I set the bottom race and bearing. I put the steering shaft in with the worm drive in the middle. I put a new race in the steering shaft cover tube. When I put the steering tube in place the steering shaft is naturally wanting to push hard toward the rear of the tractor and I had to push on it to center it in the tube. I put a new bearing cup in the top of the tube. When trying to set the preload without the sector shafts in place it feels really tight even with a full shim pack (3 or 4) installed. I don't get any noticable end play but the shaft will turn with the steering wheel. I added some thin washers on top of the shim pack to try to loosen up the preload, but it still feels tight. I installed both sector shafts and I believe the teeth are aligned according to the manual. There is not any noticeable adjustment to the backlash by turning the eccentric covers so I'm keeping the grooves in the cover at 6 o'clock which seems to fit together the best. when i turn the wheel everything feels fairly smooth and easy to turn. When I hook the tie rods back on and try to turn the wheel with the front jacked up i get tightness and sticking and then the steering shaft pushes up and both thrust bearings bend and the top bearing falls apart. It seems that turning the steering to the right causes the worm gear to drive the gear all the way to the bottom bearing and that pushed the steering shaft up hard enough to destroy the bearings.
What am I doing wrong? Is the welsh plug supposed to support the steering shaft do i have that upside down? Do I need more shims? I'm at a loss....
thanks
Rob
I put the welsh plug in with the curve down (when looking down from the top of the box the plug looks like a bowl). I set the bottom race and bearing. I put the steering shaft in with the worm drive in the middle. I put a new race in the steering shaft cover tube. When I put the steering tube in place the steering shaft is naturally wanting to push hard toward the rear of the tractor and I had to push on it to center it in the tube. I put a new bearing cup in the top of the tube. When trying to set the preload without the sector shafts in place it feels really tight even with a full shim pack (3 or 4) installed. I don't get any noticable end play but the shaft will turn with the steering wheel. I added some thin washers on top of the shim pack to try to loosen up the preload, but it still feels tight. I installed both sector shafts and I believe the teeth are aligned according to the manual. There is not any noticeable adjustment to the backlash by turning the eccentric covers so I'm keeping the grooves in the cover at 6 o'clock which seems to fit together the best. when i turn the wheel everything feels fairly smooth and easy to turn. When I hook the tie rods back on and try to turn the wheel with the front jacked up i get tightness and sticking and then the steering shaft pushes up and both thrust bearings bend and the top bearing falls apart. It seems that turning the steering to the right causes the worm gear to drive the gear all the way to the bottom bearing and that pushed the steering shaft up hard enough to destroy the bearings.
What am I doing wrong? Is the welsh plug supposed to support the steering shaft do i have that upside down? Do I need more shims? I'm at a loss....
thanks
Rob
