Farm Equipment - Ac d17 series 3 lift arms down speed

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Ac d17 series 3 lift arms down speed

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=208826
Printed Date: 07 Nov 2025 at 11:40pm
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Topic: Ac d17 series 3 lift arms down speed

Posted By: Vwcountry
Subject: Ac d17 series 3 lift arms down speed
Date Posted: 07 Nov 2025 at 4:36pm

The lift arms work just fine but when you let them down you can’t do it slowly it comes down like a hammer. Is this normal thanks

Replies:

Posted By: DrAllis
Date Posted: 07 Nov 2025 at 5:52pm

I guess, yes. What exactly are you doing that causes you to complain?? A "rate-of-drop" valve could be installed in-line to adjust oil return to the sump while not affecting raise speed.

Posted By: Clay
Date Posted: 07 Nov 2025 at 6:07pm

On the left hand side sheet is a one inch hole for the lowering adjustment.

This is the LIFT_LOWER Lever Linkage adjustment knob.

Turning the knob to the to the right increases the lowering adjustment. Turning it to the left slows the lowering adjustment.

I have a series II D-17. Not sure if it applies to other series.

Posted By: DrAllis
Date Posted: 07 Nov 2025 at 6:16pm

That adjustment screw only works when using the Traction Booster system, like on a mounted plow. If you've ever plowed, the plow still drops like a brick at the end of the field. That speed drop adjustment screw keeps the hand lever at the top of the bottom window and meters the return oil when the TBoost system is releasing the lift pressure. Early model D-17's did not have this, and the performance of the weight transfer system was lacking. So,this feature had to be created and works well if it is adjusted correctly. EDIT: I've never tried this but maybe it could work. If you screw that speed adjustment screw "in" (clockwise) as far as it will go, maybe the lift/lower lever stroke would be altered enough to where the hold valve plunger releases up higher into the mid-range of the levers stroke. Then, your hand could better control drop speed. Try it.

Posted By: Clay
Date Posted: 07 Nov 2025 at 9:05pm

I pulled out my operators manual and Dr Allis is right. It works with the traction booster.

Page 37 in my OPERATING INSTRUCTIONS.

ADJUSTMENT(LIFT-LOWER Lever Linkage)

Effective on tractors D17 - 17846 and up, with the 1" hole in the left hand side sheet.

1. Place the TRACTION BOOSTER hand lever at bottom of quadrant.

2. With engine running, move the LIFT-LOWER lever to the lift position and unload pump. At this time pressure will be indicated on the TRACTION BOOSTER gauge.

3. Carefully lower the LIFT-LOWER lever until you feel the lever contact with the hold position valve plunger. Without releasing the pressure indicated on the TRACTION BOOSTER gauge, turn the lowering control adjusting nut (located through hole in left hand side sheet below fuel tank) counterclockwise until the LIFT-LOWER lever latches in the lower window on quadrant. Now turn the adjusting nut clockwise until the gauge pressure drops.