D6C Front Idler Confusion.

In February, I bought a 1967 D6C Direct Drive Dozer with serial # 74A2663. It started right up, had good oil pressure, no significant smoke, and sounded great. The chains, pads, and sprocket sections looked nearly brand new. I should have lifted it up and checked the bottom rolls, as they were junk on both sides. Fortunately, a complete set of NOS Rolls and 2 NOS Idlers were included in the sale, indicating someone had started an undercarriage job but didn’t complete it.

I replaced the right side of the machine, including adjuster seals, which was easy. Moving to the left side, the track and adjuster came apart quickly. However, I discovered 6 broken bolts holding the front idler assembly together, causing a toe-in situation and uneven wear on the idler itself. Despite heating, pounding, drilling, and some cursing, it didn’t come apart. Though the 4 big bolts holding the idler bearings came out easily, the yoke was the issue. According to my factory service manual, technicians could remove the 2 bolts on the end of the recoil rod, strike it with a hammer to separate it from the yoke, slide the rod out the back, and lift the yoke out from the front. Well, that didn’t happen. I used a 12lb sledgehammer with limited swing room, to no avail. It seemed it had never been apart since assembly.

Frustrated, I cut the recoil rod with a torch and got everything out on the ground. Here’s the dilemma: the parts book says I should have a Cat #7M1844 yoke. However, stamped on my yoke is #7M1775, and the side plates are #7M1776. I’m thinking it’s best to install new parts that match the ones that came out.

I have the correct parts book, and it indicates the recoil rod should slide in or out of the unit the equalizer bar and forward top roll mount to. It looks very tight to me. Does anyone have experience with this procedure or insights on these part number discrepancies? The number 2P7984 has also come up during my yoke search. Thanks in advance for any wisdom.

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I have a CASE 310 crawler. It looks as though the flanges on both crawlers are worn thin. I don't know what new ones look like, but I assume they were originally thicker at the perimeter than my nearly knife-edged ones.

I've noticed on other crawlers that the middle island on the idlers is solid. I’m wondering if I could use some 1/4" hot roll steel, form it around the idler over the flanges, and weld it in place to extend the idlers' life. Has anyone had experience wrapping strip steel around the idlers to rebuild them? Welding build-up would take an enormous amount of time and would need smoothing afterward.

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How wide should the island or center rib for the idler be when new? Alternatively, I may try to find someone to roll flat stock 1/4" X 3/4" edgewise into a ring and weld a ring to each side of the flanged island to widen it.

Does anyone have experience building up idlers and rollers on a crawler undercarriage? Any opinions on the do's and don'ts when rebuilding idlers and rollers? KRM

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