CA Rockshaft Diameter and Clearance
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Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=194108
Printed Date: 05 Sep 2025 at 1:13am
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Topic: CA Rockshaft Diameter and Clearance
Posted By: dfwallis
Subject: CA Rockshaft Diameter and Clearance
Date Posted: 16 Mar 2023 at 8:41pm
| Does someone know the diameter of the rockshaft bar and how much clearance there is between it and the footboard or anything else within the region from the bearings inward 3 or 4 inches? Is there 0.5 to 1 inch of clearance or greater? Can I clamp a typical split bearing block on it (block itself fixed and non-rotating with base/attachment towards the rear). |
Replies:
Posted By: tomwmn
Date Posted: 17 Mar 2023 at 2:26pm
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Hi Rocker shaft O D is 1.75 inches. Clearance between shaft and floor pan depends on how straight yours is. On mine, one side is less than 3/8 inch. Other side almost rubbing. Good luck! |
Posted By: dfwallis
Date Posted: 17 Mar 2023 at 2:46pm
hmmm, that clearance is disappointing but agrees with my very old memory. Not much room for me to wrap a split bearing around it without mods.
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tomwmn wrote:Posted By: dfwallis
Date Posted: 17 Mar 2023 at 3:41pm
I suppose a free spinning metal loop might work. Won't really impede the hydraulic actuation much. I can make it a little thin but wider for strength if needed.
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Posted By: steve(ill)
Date Posted: 17 Mar 2023 at 3:59pm
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cut a notch in the floor plate 2 inches wide and 1/2 inch deep... then plenty or room for a strap... or weld on. ------------- Like them all, but love the "B"s. |
Posted By: dfwallis
Date Posted: 17 Mar 2023 at 4:56pm
If I did that though, I might be able to make enough room for a split bearing, which would be nicer engineering wise. Was hoping not to have to cut the floor pan though.
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Posted By: tomwmn
Date Posted: 17 Mar 2023 at 5:33pm
| Find a piece of tubing with correct ID, and not too thick. Cut in half. Then modify as needed. Tubing comes in many sizes and strengths!!! |
Posted By: dfwallis
Date Posted: 17 Mar 2023 at 6:46pm
Yes, I've done that for similar uses. A bronze sleeve bearing might work also, if I decide it's sufficiently wear resistant. But I'll still have to make some sort of custom pillow block.
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Posted By: steve(ill)
Date Posted: 17 Mar 2023 at 7:11pm
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Gary... your going to find out that Steel on Steel is OK in this application.. It only move 20- 30 degrees on the shaft and / seldom moves/ very slow... Wipe grease on it before assembly and that will be good for 10 years. ...... I have that on a tractor.
you can make it as complicated as you want.. or this simple.  ------------- Like them all, but love the "B"s. |
Posted By: dfwallis
Date Posted: 17 Mar 2023 at 7:23pm
Yup, i've seen those brackets. Probably good enough. I can make a bracket for the bracket :)
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Posted By: dfwallis
Date Posted: 17 Mar 2023 at 7:24pm
I am/was an actual engineer before I retired, I like make it 'better' :)
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Posted By: steve(ill)
Date Posted: 17 Mar 2023 at 7:28pm
yea... i did that for 40 years in a prior life also...... Enjoy "modifying" and making something out of something else .  ------------- Like them all, but love the "B"s. |
Posted By: Dakota Dave
Date Posted: 17 Mar 2023 at 7:38pm
| My rock shaft just has 2 tabs welded to it with a hole through them for the top link pin the shaft rotates less than 45 deg the welded tabs dont slide around like the U clamp does. It makes for a much better top link. |
Posted By: dfwallis
Date Posted: 17 Mar 2023 at 8:12pm
I prefer to leave the tractor as original as possible besides tire size and maybe an engine tweak (and LED bulbs). Don't really want to weld anything to it, hoping for simple bolt on additions. I'm sure I can devise a clamp improvement to prevent rotation of the bracket if it turns out to be a problem. Anyway, dad has mostly drawbar implements, I just want it to be a bit more flexible. I've never encountered snap coupler implements. If I ever need to, I'll make it triple compatible :)
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