Recently I've been doing a lot of grading with a Gannon rollover scraper. The B series adjustable link rod is a PITA, so began looking for alternatives, ideally something adjustable from the seat. Weaver compact tractor parts was suggested. They have the below box leveler on their website, dimensions are good for B series, but obviously requires modification of the knuckle to fit the B26 upper lift arm ball socket. Unfortunately it's listed as not available and a phone call to Weaver indicated they don't have a restock date.
Kubota makes a ratcheting type leveling rod for B series, but pricey ($350), so took the advice of one response to my previous thread - fab it. Found a suitable candidate at Reliable Aftermarket Parts Inc, SBA370010122 Assembly. Similar to the Weaver, but it's minimum length is about the same as the fixed link rod length on the B26. Figured I could shorten it to work with the B26. With coupon got it for slightly less than $100.
The knuckle obviously needs modified, along with the extension length, and the fork pin holes are larger than the B26 lower lift arm fork attachment openings. Cut/grinded out the area between the knuckle upper pin openings (pic) to create a cavity for the lift arm ball socket. Used bushings to adapt the 7/8 knuckle openings to the 5/8 pin. Seemed a decent idea until I fitted the SBA to the lift arm and discovered the SBA motion was limited by the lift arm. Oops. Lesson learned, do a mockup first.
Knuckle modification plan B. Had already removed the SBA fork to replace with the B26 link rod fork. After a mockup, decided to extend the upper knuckle pin holes 1.5" using the legs of the removed SBA fork. The legs use the same 5/8 pin as the upper lift arm eyeballs, so no bushings needed. Adding the fork legs extended the opening for the lift arm, solving the lift arm clearance issue. Added some metal back to the cavity area near the pin hole in above pic.
SBA specs listed the adjustable center to center range of 16.5 - 20.5". The actual minimum length was 17". Adding the 1.5" fork legs to the knuckle increased the min length to 18.5". Removed an additional 1.25" from the lower cylinder to obtain 17.25" minimum. The goal was to end up with a mid-travel length of 17.25", equal to the fixed lift rod length of the B26. The leveler box is basically two sections, the upper knuckle/gearbox/screw/cylinder section and the lower cylinder/fork section which contains a threaded segment, at the top, which rides up/down on the screw as the handle is rotated. Lower cylinder is smaller diameter than upper cylinder so they overlap. The drive screw extends approx an inch beyond the upper cylinder. Tac welded the B26 fork to the lower cylinder, with a slight offset like the original, to do full mockup and make the cuts to the screw and upper cylinder to achieve the 17.25" mid length goal.
Shortening the drive screw would obviously effect the adjustment range. After some math and measurements, decided to take 1.5" off the screw (and cylinder) to obtain a 15.75" minimum. Did this in a couple increments, double checking after each cut. Given that the screw was now 1.5" shorter, the overall extension spec was reduced. Decided that a 3" range was a reasonable compromise given the SBA specs and shortened screw length. Thus, the 15.75" minimum put the modified SBA at 18.75" max extension, 1.5" up/down from the 17.25". Hope this makes sense. Finish weld on the fork and mounted on the B26. Can adjust from the seat. All that's left is to paint in Kubota dark grey.
Kubota makes a ratcheting type leveling rod for B series, but pricey ($350), so took the advice of one response to my previous thread - fab it. Found a suitable candidate at Reliable Aftermarket Parts Inc, SBA370010122 Assembly. Similar to the Weaver, but it's minimum length is about the same as the fixed link rod length on the B26. Figured I could shorten it to work with the B26. With coupon got it for slightly less than $100.
The knuckle obviously needs modified, along with the extension length, and the fork pin holes are larger than the B26 lower lift arm fork attachment openings. Cut/grinded out the area between the knuckle upper pin openings (pic) to create a cavity for the lift arm ball socket. Used bushings to adapt the 7/8 knuckle openings to the 5/8 pin. Seemed a decent idea until I fitted the SBA to the lift arm and discovered the SBA motion was limited by the lift arm. Oops. Lesson learned, do a mockup first.
Knuckle modification plan B. Had already removed the SBA fork to replace with the B26 link rod fork. After a mockup, decided to extend the upper knuckle pin holes 1.5" using the legs of the removed SBA fork. The legs use the same 5/8 pin as the upper lift arm eyeballs, so no bushings needed. Adding the fork legs extended the opening for the lift arm, solving the lift arm clearance issue. Added some metal back to the cavity area near the pin hole in above pic.
SBA specs listed the adjustable center to center range of 16.5 - 20.5". The actual minimum length was 17". Adding the 1.5" fork legs to the knuckle increased the min length to 18.5". Removed an additional 1.25" from the lower cylinder to obtain 17.25" minimum. The goal was to end up with a mid-travel length of 17.25", equal to the fixed lift rod length of the B26. The leveler box is basically two sections, the upper knuckle/gearbox/screw/cylinder section and the lower cylinder/fork section which contains a threaded segment, at the top, which rides up/down on the screw as the handle is rotated. Lower cylinder is smaller diameter than upper cylinder so they overlap. The drive screw extends approx an inch beyond the upper cylinder. Tac welded the B26 fork to the lower cylinder, with a slight offset like the original, to do full mockup and make the cuts to the screw and upper cylinder to achieve the 17.25" mid length goal.
Shortening the drive screw would obviously effect the adjustment range. After some math and measurements, decided to take 1.5" off the screw (and cylinder) to obtain a 15.75" minimum. Did this in a couple increments, double checking after each cut. Given that the screw was now 1.5" shorter, the overall extension spec was reduced. Decided that a 3" range was a reasonable compromise given the SBA specs and shortened screw length. Thus, the 15.75" minimum put the modified SBA at 18.75" max extension, 1.5" up/down from the 17.25". Hope this makes sense. Finish weld on the fork and mounted on the B26. Can adjust from the seat. All that's left is to paint in Kubota dark grey.
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