CA Lift Capacity - 3 point adapters
Printed From: Unofficial Allis
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=211499
Printed Date: 18 Sep 2026 at 9:32am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: CA Lift Capacity - 3 point adapters
Posted By: dfwallis
Subject: CA Lift Capacity - 3 point adapters
Date Posted: 27 Jun 2026 at 9:28am
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Those with an add on 3 point hitch may find that attaching the leveling arms at the cultivator pin hole 3.25 inches in from the end of the ca lift arms results in improved lift capacity, depending on geometry (or not, since the distance to the load is shorter regardless). In my case, fairly significant. Those holes better align with the lift arm attachment position also. I needed a short extender for clearance reasons. I used a weld on lift arm ball with a 5/8 hole added (TSC). I used a bent one so that I can adjust it for greater side to side play for the lower lift arms. Flip it right or left as needed. I also made a spacer to keep it in position left side or right as needed. Of course lift height is reduced a little. ------------- 1952 CA13092, CA Pickup Plow, CA Cultivator, CA Two Row Planter, Dunham-Lehr GC78 Disc, Grader Blade, 3pt Fm180 Finish Mower |
Replies:
Posted By: SyncPil
Date Posted: 27 Jun 2026 at 9:41am
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Thanks for sharing this. It's a clever modification. I'm sure it'll help some of us looking to get a little more lift capacity out of their 3-point setup. |
Posted By: dfwallis
Date Posted: 01 Jul 2026 at 1:08pm
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I've decided to experiment with flat bar inserts inside the CA lift arms. I can then add multiple connection point holes for the 3 point leveling arms along it's bottom length. I don't want to mod the tractor itself. An insert that uses existing holes in the CA lift arms allows me multiple force vs lift height tradeoff options for lift capacity. Superficially (thought experiment), this seems like the best most flexible option so far. Hopefully, this doesn't allow more force than the CA lift arm welds can handle. ------------- 1952 CA13092, CA Pickup Plow, CA Cultivator, CA Two Row Planter, Dunham-Lehr GC78 Disc, Grader Blade, 3pt Fm180 Finish Mower |
Posted By: steve(ill)
Date Posted: 01 Jul 2026 at 9:41pm
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i wish you had a picture to go along with this to visualize the modifcation.. ------------- Like them all, but love the "B"s. |
Posted By: dfwallis
Date Posted: 02 Jul 2026 at 8:41am
------------- 1952 CA13092, CA Pickup Plow, CA Cultivator, CA Two Row Planter, Dunham-Lehr GC78 Disc, Grader Blade, 3pt Fm180 Finish Mower |
Posted By: dfwallis
Date Posted: 02 Jul 2026 at 9:20am
I do see a lot of tractors where the upper attachments of the leveling arms are very far back from the attachment to the lower lift arms (the upper lift arms are very short in many cases). This makes the leveling arms have a very steep angle toward the tractor. I wonder if there's an "ideal" angle.  ------------- 1952 CA13092, CA Pickup Plow, CA Cultivator, CA Two Row Planter, Dunham-Lehr GC78 Disc, Grader Blade, 3pt Fm180 Finish Mower |
Posted By: steve(ill)
Date Posted: 02 Jul 2026 at 9:49am
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the PERFECT angle from a design force point of view would be 90 degrees... Of course that is not always possible.. Given a big enough cylinder and pressure, you can change the angle to anything you want. REAL STEEP angles use a lot of wasted force to lift the load.. The upper arms being short , have the pivot pin only travel a short distance compared to the pin end of the lower 3 point arm... Your right, its a "give and take" to get what you want.. Lots of lift (distance), or lots of force (load)... or a compromise inbetween. ------------- Like them all, but love the "B"s. |
Posted By: dfwallis
Date Posted: 02 Jul 2026 at 10:18am
90 deg is what I would assume, but during some portion of the lift, even the above angled attachment will be close to 90 degrees. Looks complicated to find the best angle of attachment when you're lifting through two different arcs (upper and lower). i would have thought you'd want the most advantage at the bottom, but maybe you want it in the middle of the throw and split the difference. ------------- 1952 CA13092, CA Pickup Plow, CA Cultivator, CA Two Row Planter, Dunham-Lehr GC78 Disc, Grader Blade, 3pt Fm180 Finish Mower |
steve(ill) wrote:Posted By: Les Kerf
Date Posted: 02 Jul 2026 at 1:30pm
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Rule #1: Every engineering endeavor is a compromise Rule #2: EVERYTHING is a spring
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Posted By: dfwallis
Date Posted: 02 Jul 2026 at 7:31pm
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I've done a brief image survey and it seems like the majority of 3 point leveling arm connections across brands are at about a 30-40 degree angle like shown above, when in the down position. That doesn'tseem optimal. ------------- 1952 CA13092, CA Pickup Plow, CA Cultivator, CA Two Row Planter, Dunham-Lehr GC78 Disc, Grader Blade, 3pt Fm180 Finish Mower |
Posted By: dfwallis
Date Posted: 05 Jul 2026 at 8:25pm
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I've decided to also design an improved top link bracket. The below is the one I had selected (OK Tractor), but it slides on the rock shaft. I don't want to mod the rockshaft (no welding, no new holes). I designed a clamp for this to reduce sliding (I bought this extra wide one thinking the clamping force would be better), but it is insufficient when you're trying to dig a dirt scoop into the ground. While it is fine for pulling support, pushing on something can cause it to rotate up toward the seat. It is blocked from going down by the PTO guard. I believe I can just add a bar/angle all the way across the rockshaft and attach it to the lift arms to prevent rotation (of course the whole thing will still rotate with the rockshaft, just not independently). I'll use horizontal top link mounting bracket holes rather than this one which is vertical and not quite ideally compatible with the range of motion of the top links themselves. 
------------- 1952 CA13092, CA Pickup Plow, CA Cultivator, CA Two Row Planter, Dunham-Lehr GC78 Disc, Grader Blade, 3pt Fm180 Finish Mower |